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14726903c8
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
7494 lines
193 KiB
C
7494 lines
193 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* memcontrol.c - Memory Controller
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*
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* Copyright IBM Corporation, 2007
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* Author Balbir Singh <balbir@linux.vnet.ibm.com>
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*
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* Copyright 2007 OpenVZ SWsoft Inc
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* Author: Pavel Emelianov <xemul@openvz.org>
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*
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* Memory thresholds
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* Copyright (C) 2009 Nokia Corporation
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* Author: Kirill A. Shutemov
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*
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* Kernel Memory Controller
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* Copyright (C) 2012 Parallels Inc. and Google Inc.
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* Authors: Glauber Costa and Suleiman Souhlal
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*
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* Native page reclaim
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* Charge lifetime sanitation
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* Lockless page tracking & accounting
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* Unified hierarchy configuration model
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* Copyright (C) 2015 Red Hat, Inc., Johannes Weiner
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*
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* Per memcg lru locking
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* Copyright (C) 2020 Alibaba, Inc, Alex Shi
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*/
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#include <linux/page_counter.h>
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#include <linux/memcontrol.h>
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#include <linux/cgroup.h>
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#include <linux/pagewalk.h>
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#include <linux/sched/mm.h>
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#include <linux/shmem_fs.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/vm_event_item.h>
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#include <linux/smp.h>
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#include <linux/page-flags.h>
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#include <linux/backing-dev.h>
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#include <linux/bit_spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/limits.h>
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/spinlock.h>
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#include <linux/eventfd.h>
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#include <linux/poll.h>
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#include <linux/sort.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/vmpressure.h>
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#include <linux/mm_inline.h>
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#include <linux/swap_cgroup.h>
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#include <linux/cpu.h>
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#include <linux/oom.h>
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#include <linux/lockdep.h>
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#include <linux/file.h>
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#include <linux/tracehook.h>
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#include <linux/psi.h>
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#include <linux/seq_buf.h>
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#include "internal.h"
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#include <net/sock.h>
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#include <net/ip.h>
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#include "slab.h"
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#include <linux/uaccess.h>
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#include <trace/events/vmscan.h>
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struct cgroup_subsys memory_cgrp_subsys __read_mostly;
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EXPORT_SYMBOL(memory_cgrp_subsys);
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struct mem_cgroup *root_mem_cgroup __read_mostly;
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/* Active memory cgroup to use from an interrupt context */
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DEFINE_PER_CPU(struct mem_cgroup *, int_active_memcg);
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EXPORT_PER_CPU_SYMBOL_GPL(int_active_memcg);
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/* Socket memory accounting disabled? */
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static bool cgroup_memory_nosocket __ro_after_init;
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/* Kernel memory accounting disabled? */
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bool cgroup_memory_nokmem __ro_after_init;
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/* Whether the swap controller is active */
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#ifdef CONFIG_MEMCG_SWAP
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bool cgroup_memory_noswap __ro_after_init;
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#else
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#define cgroup_memory_noswap 1
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#endif
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#ifdef CONFIG_CGROUP_WRITEBACK
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static DECLARE_WAIT_QUEUE_HEAD(memcg_cgwb_frn_waitq);
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#endif
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/* Whether legacy memory+swap accounting is active */
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static bool do_memsw_account(void)
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{
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return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_noswap;
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}
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/* memcg and lruvec stats flushing */
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static void flush_memcg_stats_dwork(struct work_struct *w);
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static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork);
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static void flush_memcg_stats_work(struct work_struct *w);
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static DECLARE_WORK(stats_flush_work, flush_memcg_stats_work);
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static DEFINE_PER_CPU(unsigned int, stats_flush_threshold);
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static DEFINE_SPINLOCK(stats_flush_lock);
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#define THRESHOLDS_EVENTS_TARGET 128
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#define SOFTLIMIT_EVENTS_TARGET 1024
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/*
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* Cgroups above their limits are maintained in a RB-Tree, independent of
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* their hierarchy representation
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*/
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struct mem_cgroup_tree_per_node {
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struct rb_root rb_root;
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struct rb_node *rb_rightmost;
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spinlock_t lock;
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};
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struct mem_cgroup_tree {
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struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
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};
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static struct mem_cgroup_tree soft_limit_tree __read_mostly;
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/* for OOM */
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struct mem_cgroup_eventfd_list {
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struct list_head list;
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struct eventfd_ctx *eventfd;
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};
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/*
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* cgroup_event represents events which userspace want to receive.
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*/
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struct mem_cgroup_event {
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/*
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* memcg which the event belongs to.
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*/
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struct mem_cgroup *memcg;
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/*
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* eventfd to signal userspace about the event.
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*/
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struct eventfd_ctx *eventfd;
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/*
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* Each of these stored in a list by the cgroup.
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*/
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struct list_head list;
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/*
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* register_event() callback will be used to add new userspace
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* waiter for changes related to this event. Use eventfd_signal()
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* on eventfd to send notification to userspace.
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*/
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int (*register_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd, const char *args);
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/*
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* unregister_event() callback will be called when userspace closes
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* the eventfd or on cgroup removing. This callback must be set,
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* if you want provide notification functionality.
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*/
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void (*unregister_event)(struct mem_cgroup *memcg,
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struct eventfd_ctx *eventfd);
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/*
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* All fields below needed to unregister event when
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* userspace closes eventfd.
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*/
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poll_table pt;
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wait_queue_head_t *wqh;
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wait_queue_entry_t wait;
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struct work_struct remove;
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};
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static void mem_cgroup_threshold(struct mem_cgroup *memcg);
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static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
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/* Stuffs for move charges at task migration. */
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/*
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* Types of charges to be moved.
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*/
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#define MOVE_ANON 0x1U
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#define MOVE_FILE 0x2U
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#define MOVE_MASK (MOVE_ANON | MOVE_FILE)
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/* "mc" and its members are protected by cgroup_mutex */
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static struct move_charge_struct {
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spinlock_t lock; /* for from, to */
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struct mm_struct *mm;
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struct mem_cgroup *from;
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struct mem_cgroup *to;
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unsigned long flags;
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unsigned long precharge;
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unsigned long moved_charge;
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unsigned long moved_swap;
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struct task_struct *moving_task; /* a task moving charges */
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wait_queue_head_t waitq; /* a waitq for other context */
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} mc = {
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.lock = __SPIN_LOCK_UNLOCKED(mc.lock),
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.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
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};
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/*
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* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
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* limit reclaim to prevent infinite loops, if they ever occur.
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*/
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#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
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#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
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/* for encoding cft->private value on file */
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enum res_type {
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_MEM,
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_MEMSWAP,
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_OOM_TYPE,
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_KMEM,
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_TCP,
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};
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#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
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#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
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#define MEMFILE_ATTR(val) ((val) & 0xffff)
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/* Used for OOM notifier */
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#define OOM_CONTROL (0)
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/*
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* Iteration constructs for visiting all cgroups (under a tree). If
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* loops are exited prematurely (break), mem_cgroup_iter_break() must
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* be used for reference counting.
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*/
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#define for_each_mem_cgroup_tree(iter, root) \
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for (iter = mem_cgroup_iter(root, NULL, NULL); \
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iter != NULL; \
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iter = mem_cgroup_iter(root, iter, NULL))
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#define for_each_mem_cgroup(iter) \
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for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
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iter != NULL; \
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iter = mem_cgroup_iter(NULL, iter, NULL))
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static inline bool should_force_charge(void)
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{
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return tsk_is_oom_victim(current) || fatal_signal_pending(current) ||
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(current->flags & PF_EXITING);
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}
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/* Some nice accessors for the vmpressure. */
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struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
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{
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if (!memcg)
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memcg = root_mem_cgroup;
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return &memcg->vmpressure;
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}
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struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr)
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{
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return container_of(vmpr, struct mem_cgroup, vmpressure);
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}
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#ifdef CONFIG_MEMCG_KMEM
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extern spinlock_t css_set_lock;
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bool mem_cgroup_kmem_disabled(void)
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{
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return cgroup_memory_nokmem;
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}
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static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
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unsigned int nr_pages);
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static void obj_cgroup_release(struct percpu_ref *ref)
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{
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struct obj_cgroup *objcg = container_of(ref, struct obj_cgroup, refcnt);
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unsigned int nr_bytes;
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unsigned int nr_pages;
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unsigned long flags;
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/*
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* At this point all allocated objects are freed, and
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* objcg->nr_charged_bytes can't have an arbitrary byte value.
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* However, it can be PAGE_SIZE or (x * PAGE_SIZE).
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*
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* The following sequence can lead to it:
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* 1) CPU0: objcg == stock->cached_objcg
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* 2) CPU1: we do a small allocation (e.g. 92 bytes),
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* PAGE_SIZE bytes are charged
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* 3) CPU1: a process from another memcg is allocating something,
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* the stock if flushed,
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* objcg->nr_charged_bytes = PAGE_SIZE - 92
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* 5) CPU0: we do release this object,
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* 92 bytes are added to stock->nr_bytes
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* 6) CPU0: stock is flushed,
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* 92 bytes are added to objcg->nr_charged_bytes
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*
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* In the result, nr_charged_bytes == PAGE_SIZE.
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* This page will be uncharged in obj_cgroup_release().
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*/
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nr_bytes = atomic_read(&objcg->nr_charged_bytes);
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WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1));
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nr_pages = nr_bytes >> PAGE_SHIFT;
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if (nr_pages)
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obj_cgroup_uncharge_pages(objcg, nr_pages);
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spin_lock_irqsave(&css_set_lock, flags);
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list_del(&objcg->list);
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spin_unlock_irqrestore(&css_set_lock, flags);
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percpu_ref_exit(ref);
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kfree_rcu(objcg, rcu);
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}
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static struct obj_cgroup *obj_cgroup_alloc(void)
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{
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struct obj_cgroup *objcg;
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int ret;
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objcg = kzalloc(sizeof(struct obj_cgroup), GFP_KERNEL);
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if (!objcg)
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return NULL;
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ret = percpu_ref_init(&objcg->refcnt, obj_cgroup_release, 0,
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GFP_KERNEL);
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if (ret) {
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kfree(objcg);
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return NULL;
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}
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INIT_LIST_HEAD(&objcg->list);
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return objcg;
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}
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static void memcg_reparent_objcgs(struct mem_cgroup *memcg,
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struct mem_cgroup *parent)
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{
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struct obj_cgroup *objcg, *iter;
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objcg = rcu_replace_pointer(memcg->objcg, NULL, true);
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spin_lock_irq(&css_set_lock);
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/* 1) Ready to reparent active objcg. */
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list_add(&objcg->list, &memcg->objcg_list);
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/* 2) Reparent active objcg and already reparented objcgs to parent. */
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list_for_each_entry(iter, &memcg->objcg_list, list)
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WRITE_ONCE(iter->memcg, parent);
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/* 3) Move already reparented objcgs to the parent's list */
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list_splice(&memcg->objcg_list, &parent->objcg_list);
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spin_unlock_irq(&css_set_lock);
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percpu_ref_kill(&objcg->refcnt);
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}
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/*
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* This will be used as a shrinker list's index.
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* The main reason for not using cgroup id for this:
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* this works better in sparse environments, where we have a lot of memcgs,
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* but only a few kmem-limited. Or also, if we have, for instance, 200
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* memcgs, and none but the 200th is kmem-limited, we'd have to have a
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* 200 entry array for that.
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*
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* The current size of the caches array is stored in memcg_nr_cache_ids. It
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* will double each time we have to increase it.
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*/
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static DEFINE_IDA(memcg_cache_ida);
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int memcg_nr_cache_ids;
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/* Protects memcg_nr_cache_ids */
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static DECLARE_RWSEM(memcg_cache_ids_sem);
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void memcg_get_cache_ids(void)
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{
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down_read(&memcg_cache_ids_sem);
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}
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void memcg_put_cache_ids(void)
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{
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up_read(&memcg_cache_ids_sem);
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}
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/*
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* MIN_SIZE is different than 1, because we would like to avoid going through
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* the alloc/free process all the time. In a small machine, 4 kmem-limited
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* cgroups is a reasonable guess. In the future, it could be a parameter or
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* tunable, but that is strictly not necessary.
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*
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* MAX_SIZE should be as large as the number of cgrp_ids. Ideally, we could get
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* this constant directly from cgroup, but it is understandable that this is
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* better kept as an internal representation in cgroup.c. In any case, the
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* cgrp_id space is not getting any smaller, and we don't have to necessarily
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* increase ours as well if it increases.
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*/
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#define MEMCG_CACHES_MIN_SIZE 4
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#define MEMCG_CACHES_MAX_SIZE MEM_CGROUP_ID_MAX
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/*
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* A lot of the calls to the cache allocation functions are expected to be
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* inlined by the compiler. Since the calls to memcg_slab_pre_alloc_hook() are
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* conditional to this static branch, we'll have to allow modules that does
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* kmem_cache_alloc and the such to see this symbol as well
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*/
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DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key);
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EXPORT_SYMBOL(memcg_kmem_enabled_key);
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#endif
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/**
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* mem_cgroup_css_from_page - css of the memcg associated with a page
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* @page: page of interest
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*
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* If memcg is bound to the default hierarchy, css of the memcg associated
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* with @page is returned. The returned css remains associated with @page
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* until it is released.
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*
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* If memcg is bound to a traditional hierarchy, the css of root_mem_cgroup
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* is returned.
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*/
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struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page)
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{
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struct mem_cgroup *memcg;
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memcg = page_memcg(page);
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if (!memcg || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
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memcg = root_mem_cgroup;
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return &memcg->css;
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}
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/**
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* page_cgroup_ino - return inode number of the memcg a page is charged to
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* @page: the page
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*
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* Look up the closest online ancestor of the memory cgroup @page is charged to
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* and return its inode number or 0 if @page is not charged to any cgroup. It
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* is safe to call this function without holding a reference to @page.
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*
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* Note, this function is inherently racy, because there is nothing to prevent
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* the cgroup inode from getting torn down and potentially reallocated a moment
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* after page_cgroup_ino() returns, so it only should be used by callers that
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* do not care (such as procfs interfaces).
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*/
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ino_t page_cgroup_ino(struct page *page)
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{
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struct mem_cgroup *memcg;
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unsigned long ino = 0;
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rcu_read_lock();
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memcg = page_memcg_check(page);
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while (memcg && !(memcg->css.flags & CSS_ONLINE))
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memcg = parent_mem_cgroup(memcg);
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if (memcg)
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ino = cgroup_ino(memcg->css.cgroup);
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rcu_read_unlock();
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return ino;
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}
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static struct mem_cgroup_per_node *
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mem_cgroup_page_nodeinfo(struct mem_cgroup *memcg, struct page *page)
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{
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int nid = page_to_nid(page);
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|
|
return memcg->nodeinfo[nid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_node *
|
|
soft_limit_tree_node(int nid)
|
|
{
|
|
return soft_limit_tree.rb_tree_per_node[nid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_node *
|
|
soft_limit_tree_from_page(struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
|
|
return soft_limit_tree.rb_tree_per_node[nid];
|
|
}
|
|
|
|
static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
|
|
struct mem_cgroup_tree_per_node *mctz,
|
|
unsigned long new_usage_in_excess)
|
|
{
|
|
struct rb_node **p = &mctz->rb_root.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct mem_cgroup_per_node *mz_node;
|
|
bool rightmost = true;
|
|
|
|
if (mz->on_tree)
|
|
return;
|
|
|
|
mz->usage_in_excess = new_usage_in_excess;
|
|
if (!mz->usage_in_excess)
|
|
return;
|
|
while (*p) {
|
|
parent = *p;
|
|
mz_node = rb_entry(parent, struct mem_cgroup_per_node,
|
|
tree_node);
|
|
if (mz->usage_in_excess < mz_node->usage_in_excess) {
|
|
p = &(*p)->rb_left;
|
|
rightmost = false;
|
|
} else {
|
|
p = &(*p)->rb_right;
|
|
}
|
|
}
|
|
|
|
if (rightmost)
|
|
mctz->rb_rightmost = &mz->tree_node;
|
|
|
|
rb_link_node(&mz->tree_node, parent, p);
|
|
rb_insert_color(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = true;
|
|
}
|
|
|
|
static void __mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
|
|
struct mem_cgroup_tree_per_node *mctz)
|
|
{
|
|
if (!mz->on_tree)
|
|
return;
|
|
|
|
if (&mz->tree_node == mctz->rb_rightmost)
|
|
mctz->rb_rightmost = rb_prev(&mz->tree_node);
|
|
|
|
rb_erase(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = false;
|
|
}
|
|
|
|
static void mem_cgroup_remove_exceeded(struct mem_cgroup_per_node *mz,
|
|
struct mem_cgroup_tree_per_node *mctz)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&mctz->lock, flags);
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
spin_unlock_irqrestore(&mctz->lock, flags);
|
|
}
|
|
|
|
static unsigned long soft_limit_excess(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long nr_pages = page_counter_read(&memcg->memory);
|
|
unsigned long soft_limit = READ_ONCE(memcg->soft_limit);
|
|
unsigned long excess = 0;
|
|
|
|
if (nr_pages > soft_limit)
|
|
excess = nr_pages - soft_limit;
|
|
|
|
return excess;
|
|
}
|
|
|
|
static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
unsigned long excess;
|
|
struct mem_cgroup_per_node *mz;
|
|
struct mem_cgroup_tree_per_node *mctz;
|
|
|
|
mctz = soft_limit_tree_from_page(page);
|
|
if (!mctz)
|
|
return;
|
|
/*
|
|
* Necessary to update all ancestors when hierarchy is used.
|
|
* because their event counter is not touched.
|
|
*/
|
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) {
|
|
mz = mem_cgroup_page_nodeinfo(memcg, page);
|
|
excess = soft_limit_excess(memcg);
|
|
/*
|
|
* We have to update the tree if mz is on RB-tree or
|
|
* mem is over its softlimit.
|
|
*/
|
|
if (excess || mz->on_tree) {
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&mctz->lock, flags);
|
|
/* if on-tree, remove it */
|
|
if (mz->on_tree)
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
/*
|
|
* Insert again. mz->usage_in_excess will be updated.
|
|
* If excess is 0, no tree ops.
|
|
*/
|
|
__mem_cgroup_insert_exceeded(mz, mctz, excess);
|
|
spin_unlock_irqrestore(&mctz->lock, flags);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_tree_per_node *mctz;
|
|
struct mem_cgroup_per_node *mz;
|
|
int nid;
|
|
|
|
for_each_node(nid) {
|
|
mz = memcg->nodeinfo[nid];
|
|
mctz = soft_limit_tree_node(nid);
|
|
if (mctz)
|
|
mem_cgroup_remove_exceeded(mz, mctz);
|
|
}
|
|
}
|
|
|
|
static struct mem_cgroup_per_node *
|
|
__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
|
|
{
|
|
struct mem_cgroup_per_node *mz;
|
|
|
|
retry:
|
|
mz = NULL;
|
|
if (!mctz->rb_rightmost)
|
|
goto done; /* Nothing to reclaim from */
|
|
|
|
mz = rb_entry(mctz->rb_rightmost,
|
|
struct mem_cgroup_per_node, tree_node);
|
|
/*
|
|
* Remove the node now but someone else can add it back,
|
|
* we will to add it back at the end of reclaim to its correct
|
|
* position in the tree.
|
|
*/
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
if (!soft_limit_excess(mz->memcg) ||
|
|
!css_tryget(&mz->memcg->css))
|
|
goto retry;
|
|
done:
|
|
return mz;
|
|
}
|
|
|
|
static struct mem_cgroup_per_node *
|
|
mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_node *mctz)
|
|
{
|
|
struct mem_cgroup_per_node *mz;
|
|
|
|
spin_lock_irq(&mctz->lock);
|
|
mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
spin_unlock_irq(&mctz->lock);
|
|
return mz;
|
|
}
|
|
|
|
/**
|
|
* __mod_memcg_state - update cgroup memory statistics
|
|
* @memcg: the memory cgroup
|
|
* @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
|
|
* @val: delta to add to the counter, can be negative
|
|
*/
|
|
void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
__this_cpu_add(memcg->vmstats_percpu->state[idx], val);
|
|
cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id());
|
|
}
|
|
|
|
/* idx can be of type enum memcg_stat_item or node_stat_item. */
|
|
static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
|
|
{
|
|
long x = 0;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
x += per_cpu(memcg->vmstats_percpu->state[idx], cpu);
|
|
#ifdef CONFIG_SMP
|
|
if (x < 0)
|
|
x = 0;
|
|
#endif
|
|
return x;
|
|
}
|
|
|
|
void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
|
|
int val)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
struct mem_cgroup *memcg;
|
|
|
|
pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
|
|
memcg = pn->memcg;
|
|
|
|
/* Update memcg */
|
|
__mod_memcg_state(memcg, idx, val);
|
|
|
|
/* Update lruvec */
|
|
__this_cpu_add(pn->lruvec_stats_percpu->state[idx], val);
|
|
if (!(__this_cpu_inc_return(stats_flush_threshold) % MEMCG_CHARGE_BATCH))
|
|
queue_work(system_unbound_wq, &stats_flush_work);
|
|
}
|
|
|
|
/**
|
|
* __mod_lruvec_state - update lruvec memory statistics
|
|
* @lruvec: the lruvec
|
|
* @idx: the stat item
|
|
* @val: delta to add to the counter, can be negative
|
|
*
|
|
* The lruvec is the intersection of the NUMA node and a cgroup. This
|
|
* function updates the all three counters that are affected by a
|
|
* change of state at this level: per-node, per-cgroup, per-lruvec.
|
|
*/
|
|
void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
|
|
int val)
|
|
{
|
|
/* Update node */
|
|
__mod_node_page_state(lruvec_pgdat(lruvec), idx, val);
|
|
|
|
/* Update memcg and lruvec */
|
|
if (!mem_cgroup_disabled())
|
|
__mod_memcg_lruvec_state(lruvec, idx, val);
|
|
}
|
|
|
|
void __mod_lruvec_page_state(struct page *page, enum node_stat_item idx,
|
|
int val)
|
|
{
|
|
struct page *head = compound_head(page); /* rmap on tail pages */
|
|
struct mem_cgroup *memcg;
|
|
pg_data_t *pgdat = page_pgdat(page);
|
|
struct lruvec *lruvec;
|
|
|
|
rcu_read_lock();
|
|
memcg = page_memcg(head);
|
|
/* Untracked pages have no memcg, no lruvec. Update only the node */
|
|
if (!memcg) {
|
|
rcu_read_unlock();
|
|
__mod_node_page_state(pgdat, idx, val);
|
|
return;
|
|
}
|
|
|
|
lruvec = mem_cgroup_lruvec(memcg, pgdat);
|
|
__mod_lruvec_state(lruvec, idx, val);
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL(__mod_lruvec_page_state);
|
|
|
|
void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val)
|
|
{
|
|
pg_data_t *pgdat = page_pgdat(virt_to_page(p));
|
|
struct mem_cgroup *memcg;
|
|
struct lruvec *lruvec;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_obj(p);
|
|
|
|
/*
|
|
* Untracked pages have no memcg, no lruvec. Update only the
|
|
* node. If we reparent the slab objects to the root memcg,
|
|
* when we free the slab object, we need to update the per-memcg
|
|
* vmstats to keep it correct for the root memcg.
|
|
*/
|
|
if (!memcg) {
|
|
__mod_node_page_state(pgdat, idx, val);
|
|
} else {
|
|
lruvec = mem_cgroup_lruvec(memcg, pgdat);
|
|
__mod_lruvec_state(lruvec, idx, val);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/*
|
|
* mod_objcg_mlstate() may be called with irq enabled, so
|
|
* mod_memcg_lruvec_state() should be used.
|
|
*/
|
|
static inline void mod_objcg_mlstate(struct obj_cgroup *objcg,
|
|
struct pglist_data *pgdat,
|
|
enum node_stat_item idx, int nr)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct lruvec *lruvec;
|
|
|
|
rcu_read_lock();
|
|
memcg = obj_cgroup_memcg(objcg);
|
|
lruvec = mem_cgroup_lruvec(memcg, pgdat);
|
|
mod_memcg_lruvec_state(lruvec, idx, nr);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* __count_memcg_events - account VM events in a cgroup
|
|
* @memcg: the memory cgroup
|
|
* @idx: the event item
|
|
* @count: the number of events that occurred
|
|
*/
|
|
void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
|
|
unsigned long count)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
__this_cpu_add(memcg->vmstats_percpu->events[idx], count);
|
|
cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id());
|
|
}
|
|
|
|
static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
|
|
{
|
|
return READ_ONCE(memcg->vmstats.events[event]);
|
|
}
|
|
|
|
static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
|
|
{
|
|
long x = 0;
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
x += per_cpu(memcg->vmstats_percpu->events[event], cpu);
|
|
return x;
|
|
}
|
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
int nr_pages)
|
|
{
|
|
/* pagein of a big page is an event. So, ignore page size */
|
|
if (nr_pages > 0)
|
|
__count_memcg_events(memcg, PGPGIN, 1);
|
|
else {
|
|
__count_memcg_events(memcg, PGPGOUT, 1);
|
|
nr_pages = -nr_pages; /* for event */
|
|
}
|
|
|
|
__this_cpu_add(memcg->vmstats_percpu->nr_page_events, nr_pages);
|
|
}
|
|
|
|
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_target target)
|
|
{
|
|
unsigned long val, next;
|
|
|
|
val = __this_cpu_read(memcg->vmstats_percpu->nr_page_events);
|
|
next = __this_cpu_read(memcg->vmstats_percpu->targets[target]);
|
|
/* from time_after() in jiffies.h */
|
|
if ((long)(next - val) < 0) {
|
|
switch (target) {
|
|
case MEM_CGROUP_TARGET_THRESH:
|
|
next = val + THRESHOLDS_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_SOFTLIMIT:
|
|
next = val + SOFTLIMIT_EVENTS_TARGET;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
__this_cpu_write(memcg->vmstats_percpu->targets[target], next);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check events in order.
|
|
*
|
|
*/
|
|
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
/* threshold event is triggered in finer grain than soft limit */
|
|
if (unlikely(mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_THRESH))) {
|
|
bool do_softlimit;
|
|
|
|
do_softlimit = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_SOFTLIMIT);
|
|
mem_cgroup_threshold(memcg);
|
|
if (unlikely(do_softlimit))
|
|
mem_cgroup_update_tree(memcg, page);
|
|
}
|
|
}
|
|
|
|
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
|
|
{
|
|
/*
|
|
* mm_update_next_owner() may clear mm->owner to NULL
|
|
* if it races with swapoff, page migration, etc.
|
|
* So this can be called with p == NULL.
|
|
*/
|
|
if (unlikely(!p))
|
|
return NULL;
|
|
|
|
return mem_cgroup_from_css(task_css(p, memory_cgrp_id));
|
|
}
|
|
EXPORT_SYMBOL(mem_cgroup_from_task);
|
|
|
|
static __always_inline struct mem_cgroup *active_memcg(void)
|
|
{
|
|
if (!in_task())
|
|
return this_cpu_read(int_active_memcg);
|
|
else
|
|
return current->active_memcg;
|
|
}
|
|
|
|
/**
|
|
* get_mem_cgroup_from_mm: Obtain a reference on given mm_struct's memcg.
|
|
* @mm: mm from which memcg should be extracted. It can be NULL.
|
|
*
|
|
* Obtain a reference on mm->memcg and returns it if successful. If mm
|
|
* is NULL, then the memcg is chosen as follows:
|
|
* 1) The active memcg, if set.
|
|
* 2) current->mm->memcg, if available
|
|
* 3) root memcg
|
|
* If mem_cgroup is disabled, NULL is returned.
|
|
*/
|
|
struct mem_cgroup *get_mem_cgroup_from_mm(struct mm_struct *mm)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
/*
|
|
* Page cache insertions can happen without an
|
|
* actual mm context, e.g. during disk probing
|
|
* on boot, loopback IO, acct() writes etc.
|
|
*
|
|
* No need to css_get on root memcg as the reference
|
|
* counting is disabled on the root level in the
|
|
* cgroup core. See CSS_NO_REF.
|
|
*/
|
|
if (unlikely(!mm)) {
|
|
memcg = active_memcg();
|
|
if (unlikely(memcg)) {
|
|
/* remote memcg must hold a ref */
|
|
css_get(&memcg->css);
|
|
return memcg;
|
|
}
|
|
mm = current->mm;
|
|
if (unlikely(!mm))
|
|
return root_mem_cgroup;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
do {
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
memcg = root_mem_cgroup;
|
|
} while (!css_tryget(&memcg->css));
|
|
rcu_read_unlock();
|
|
return memcg;
|
|
}
|
|
EXPORT_SYMBOL(get_mem_cgroup_from_mm);
|
|
|
|
static __always_inline bool memcg_kmem_bypass(void)
|
|
{
|
|
/* Allow remote memcg charging from any context. */
|
|
if (unlikely(active_memcg()))
|
|
return false;
|
|
|
|
/* Memcg to charge can't be determined. */
|
|
if (!in_task() || !current->mm || (current->flags & PF_KTHREAD))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter - iterate over memory cgroup hierarchy
|
|
* @root: hierarchy root
|
|
* @prev: previously returned memcg, NULL on first invocation
|
|
* @reclaim: cookie for shared reclaim walks, NULL for full walks
|
|
*
|
|
* Returns references to children of the hierarchy below @root, or
|
|
* @root itself, or %NULL after a full round-trip.
|
|
*
|
|
* Caller must pass the return value in @prev on subsequent
|
|
* invocations for reference counting, or use mem_cgroup_iter_break()
|
|
* to cancel a hierarchy walk before the round-trip is complete.
|
|
*
|
|
* Reclaimers can specify a node in @reclaim to divide up the memcgs
|
|
* in the hierarchy among all concurrent reclaimers operating on the
|
|
* same node.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev,
|
|
struct mem_cgroup_reclaim_cookie *reclaim)
|
|
{
|
|
struct mem_cgroup_reclaim_iter *iter;
|
|
struct cgroup_subsys_state *css = NULL;
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct mem_cgroup *pos = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
if (prev && !reclaim)
|
|
pos = prev;
|
|
|
|
rcu_read_lock();
|
|
|
|
if (reclaim) {
|
|
struct mem_cgroup_per_node *mz;
|
|
|
|
mz = root->nodeinfo[reclaim->pgdat->node_id];
|
|
iter = &mz->iter;
|
|
|
|
if (prev && reclaim->generation != iter->generation)
|
|
goto out_unlock;
|
|
|
|
while (1) {
|
|
pos = READ_ONCE(iter->position);
|
|
if (!pos || css_tryget(&pos->css))
|
|
break;
|
|
/*
|
|
* css reference reached zero, so iter->position will
|
|
* be cleared by ->css_released. However, we should not
|
|
* rely on this happening soon, because ->css_released
|
|
* is called from a work queue, and by busy-waiting we
|
|
* might block it. So we clear iter->position right
|
|
* away.
|
|
*/
|
|
(void)cmpxchg(&iter->position, pos, NULL);
|
|
}
|
|
}
|
|
|
|
if (pos)
|
|
css = &pos->css;
|
|
|
|
for (;;) {
|
|
css = css_next_descendant_pre(css, &root->css);
|
|
if (!css) {
|
|
/*
|
|
* Reclaimers share the hierarchy walk, and a
|
|
* new one might jump in right at the end of
|
|
* the hierarchy - make sure they see at least
|
|
* one group and restart from the beginning.
|
|
*/
|
|
if (!prev)
|
|
continue;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Verify the css and acquire a reference. The root
|
|
* is provided by the caller, so we know it's alive
|
|
* and kicking, and don't take an extra reference.
|
|
*/
|
|
memcg = mem_cgroup_from_css(css);
|
|
|
|
if (css == &root->css)
|
|
break;
|
|
|
|
if (css_tryget(css))
|
|
break;
|
|
|
|
memcg = NULL;
|
|
}
|
|
|
|
if (reclaim) {
|
|
/*
|
|
* The position could have already been updated by a competing
|
|
* thread, so check that the value hasn't changed since we read
|
|
* it to avoid reclaiming from the same cgroup twice.
|
|
*/
|
|
(void)cmpxchg(&iter->position, pos, memcg);
|
|
|
|
if (pos)
|
|
css_put(&pos->css);
|
|
|
|
if (!memcg)
|
|
iter->generation++;
|
|
else if (!prev)
|
|
reclaim->generation = iter->generation;
|
|
}
|
|
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter_break - abort a hierarchy walk prematurely
|
|
* @root: hierarchy root
|
|
* @prev: last visited hierarchy member as returned by mem_cgroup_iter()
|
|
*/
|
|
void mem_cgroup_iter_break(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev)
|
|
{
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
}
|
|
|
|
static void __invalidate_reclaim_iterators(struct mem_cgroup *from,
|
|
struct mem_cgroup *dead_memcg)
|
|
{
|
|
struct mem_cgroup_reclaim_iter *iter;
|
|
struct mem_cgroup_per_node *mz;
|
|
int nid;
|
|
|
|
for_each_node(nid) {
|
|
mz = from->nodeinfo[nid];
|
|
iter = &mz->iter;
|
|
cmpxchg(&iter->position, dead_memcg, NULL);
|
|
}
|
|
}
|
|
|
|
static void invalidate_reclaim_iterators(struct mem_cgroup *dead_memcg)
|
|
{
|
|
struct mem_cgroup *memcg = dead_memcg;
|
|
struct mem_cgroup *last;
|
|
|
|
do {
|
|
__invalidate_reclaim_iterators(memcg, dead_memcg);
|
|
last = memcg;
|
|
} while ((memcg = parent_mem_cgroup(memcg)));
|
|
|
|
/*
|
|
* When cgruop1 non-hierarchy mode is used,
|
|
* parent_mem_cgroup() does not walk all the way up to the
|
|
* cgroup root (root_mem_cgroup). So we have to handle
|
|
* dead_memcg from cgroup root separately.
|
|
*/
|
|
if (last != root_mem_cgroup)
|
|
__invalidate_reclaim_iterators(root_mem_cgroup,
|
|
dead_memcg);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_scan_tasks - iterate over tasks of a memory cgroup hierarchy
|
|
* @memcg: hierarchy root
|
|
* @fn: function to call for each task
|
|
* @arg: argument passed to @fn
|
|
*
|
|
* This function iterates over tasks attached to @memcg or to any of its
|
|
* descendants and calls @fn for each task. If @fn returns a non-zero
|
|
* value, the function breaks the iteration loop and returns the value.
|
|
* Otherwise, it will iterate over all tasks and return 0.
|
|
*
|
|
* This function must not be called for the root memory cgroup.
|
|
*/
|
|
int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
|
|
int (*fn)(struct task_struct *, void *), void *arg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
int ret = 0;
|
|
|
|
BUG_ON(memcg == root_mem_cgroup);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
struct css_task_iter it;
|
|
struct task_struct *task;
|
|
|
|
css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it);
|
|
while (!ret && (task = css_task_iter_next(&it)))
|
|
ret = fn(task, arg);
|
|
css_task_iter_end(&it);
|
|
if (ret) {
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
memcg = page_memcg(page);
|
|
|
|
if (!memcg)
|
|
VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page);
|
|
else
|
|
VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != memcg, page);
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* lock_page_lruvec - lock and return lruvec for a given page.
|
|
* @page: the page
|
|
*
|
|
* These functions are safe to use under any of the following conditions:
|
|
* - page locked
|
|
* - PageLRU cleared
|
|
* - lock_page_memcg()
|
|
* - page->_refcount is zero
|
|
*/
|
|
struct lruvec *lock_page_lruvec(struct page *page)
|
|
{
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_page_lruvec(page);
|
|
spin_lock(&lruvec->lru_lock);
|
|
|
|
lruvec_memcg_debug(lruvec, page);
|
|
|
|
return lruvec;
|
|
}
|
|
|
|
struct lruvec *lock_page_lruvec_irq(struct page *page)
|
|
{
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_page_lruvec(page);
|
|
spin_lock_irq(&lruvec->lru_lock);
|
|
|
|
lruvec_memcg_debug(lruvec, page);
|
|
|
|
return lruvec;
|
|
}
|
|
|
|
struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
|
|
{
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_page_lruvec(page);
|
|
spin_lock_irqsave(&lruvec->lru_lock, *flags);
|
|
|
|
lruvec_memcg_debug(lruvec, page);
|
|
|
|
return lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_update_lru_size - account for adding or removing an lru page
|
|
* @lruvec: mem_cgroup per zone lru vector
|
|
* @lru: index of lru list the page is sitting on
|
|
* @zid: zone id of the accounted pages
|
|
* @nr_pages: positive when adding or negative when removing
|
|
*
|
|
* This function must be called under lru_lock, just before a page is added
|
|
* to or just after a page is removed from an lru list (that ordering being
|
|
* so as to allow it to check that lru_size 0 is consistent with list_empty).
|
|
*/
|
|
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
|
|
int zid, int nr_pages)
|
|
{
|
|
struct mem_cgroup_per_node *mz;
|
|
unsigned long *lru_size;
|
|
long size;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
|
|
lru_size = &mz->lru_zone_size[zid][lru];
|
|
|
|
if (nr_pages < 0)
|
|
*lru_size += nr_pages;
|
|
|
|
size = *lru_size;
|
|
if (WARN_ONCE(size < 0,
|
|
"%s(%p, %d, %d): lru_size %ld\n",
|
|
__func__, lruvec, lru, nr_pages, size)) {
|
|
VM_BUG_ON(1);
|
|
*lru_size = 0;
|
|
}
|
|
|
|
if (nr_pages > 0)
|
|
*lru_size += nr_pages;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_margin - calculate chargeable space of a memory cgroup
|
|
* @memcg: the memory cgroup
|
|
*
|
|
* Returns the maximum amount of memory @mem can be charged with, in
|
|
* pages.
|
|
*/
|
|
static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long margin = 0;
|
|
unsigned long count;
|
|
unsigned long limit;
|
|
|
|
count = page_counter_read(&memcg->memory);
|
|
limit = READ_ONCE(memcg->memory.max);
|
|
if (count < limit)
|
|
margin = limit - count;
|
|
|
|
if (do_memsw_account()) {
|
|
count = page_counter_read(&memcg->memsw);
|
|
limit = READ_ONCE(memcg->memsw.max);
|
|
if (count < limit)
|
|
margin = min(margin, limit - count);
|
|
else
|
|
margin = 0;
|
|
}
|
|
|
|
return margin;
|
|
}
|
|
|
|
/*
|
|
* A routine for checking "mem" is under move_account() or not.
|
|
*
|
|
* Checking a cgroup is mc.from or mc.to or under hierarchy of
|
|
* moving cgroups. This is for waiting at high-memory pressure
|
|
* caused by "move".
|
|
*/
|
|
static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *from;
|
|
struct mem_cgroup *to;
|
|
bool ret = false;
|
|
/*
|
|
* Unlike task_move routines, we access mc.to, mc.from not under
|
|
* mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
|
|
*/
|
|
spin_lock(&mc.lock);
|
|
from = mc.from;
|
|
to = mc.to;
|
|
if (!from)
|
|
goto unlock;
|
|
|
|
ret = mem_cgroup_is_descendant(from, memcg) ||
|
|
mem_cgroup_is_descendant(to, memcg);
|
|
unlock:
|
|
spin_unlock(&mc.lock);
|
|
return ret;
|
|
}
|
|
|
|
static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
|
|
{
|
|
if (mc.moving_task && current != mc.moving_task) {
|
|
if (mem_cgroup_under_move(memcg)) {
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
|
|
/* moving charge context might have finished. */
|
|
if (mc.moving_task)
|
|
schedule();
|
|
finish_wait(&mc.waitq, &wait);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
struct memory_stat {
|
|
const char *name;
|
|
unsigned int idx;
|
|
};
|
|
|
|
static const struct memory_stat memory_stats[] = {
|
|
{ "anon", NR_ANON_MAPPED },
|
|
{ "file", NR_FILE_PAGES },
|
|
{ "kernel_stack", NR_KERNEL_STACK_KB },
|
|
{ "pagetables", NR_PAGETABLE },
|
|
{ "percpu", MEMCG_PERCPU_B },
|
|
{ "sock", MEMCG_SOCK },
|
|
{ "shmem", NR_SHMEM },
|
|
{ "file_mapped", NR_FILE_MAPPED },
|
|
{ "file_dirty", NR_FILE_DIRTY },
|
|
{ "file_writeback", NR_WRITEBACK },
|
|
#ifdef CONFIG_SWAP
|
|
{ "swapcached", NR_SWAPCACHE },
|
|
#endif
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
{ "anon_thp", NR_ANON_THPS },
|
|
{ "file_thp", NR_FILE_THPS },
|
|
{ "shmem_thp", NR_SHMEM_THPS },
|
|
#endif
|
|
{ "inactive_anon", NR_INACTIVE_ANON },
|
|
{ "active_anon", NR_ACTIVE_ANON },
|
|
{ "inactive_file", NR_INACTIVE_FILE },
|
|
{ "active_file", NR_ACTIVE_FILE },
|
|
{ "unevictable", NR_UNEVICTABLE },
|
|
{ "slab_reclaimable", NR_SLAB_RECLAIMABLE_B },
|
|
{ "slab_unreclaimable", NR_SLAB_UNRECLAIMABLE_B },
|
|
|
|
/* The memory events */
|
|
{ "workingset_refault_anon", WORKINGSET_REFAULT_ANON },
|
|
{ "workingset_refault_file", WORKINGSET_REFAULT_FILE },
|
|
{ "workingset_activate_anon", WORKINGSET_ACTIVATE_ANON },
|
|
{ "workingset_activate_file", WORKINGSET_ACTIVATE_FILE },
|
|
{ "workingset_restore_anon", WORKINGSET_RESTORE_ANON },
|
|
{ "workingset_restore_file", WORKINGSET_RESTORE_FILE },
|
|
{ "workingset_nodereclaim", WORKINGSET_NODERECLAIM },
|
|
};
|
|
|
|
/* Translate stat items to the correct unit for memory.stat output */
|
|
static int memcg_page_state_unit(int item)
|
|
{
|
|
switch (item) {
|
|
case MEMCG_PERCPU_B:
|
|
case NR_SLAB_RECLAIMABLE_B:
|
|
case NR_SLAB_UNRECLAIMABLE_B:
|
|
case WORKINGSET_REFAULT_ANON:
|
|
case WORKINGSET_REFAULT_FILE:
|
|
case WORKINGSET_ACTIVATE_ANON:
|
|
case WORKINGSET_ACTIVATE_FILE:
|
|
case WORKINGSET_RESTORE_ANON:
|
|
case WORKINGSET_RESTORE_FILE:
|
|
case WORKINGSET_NODERECLAIM:
|
|
return 1;
|
|
case NR_KERNEL_STACK_KB:
|
|
return SZ_1K;
|
|
default:
|
|
return PAGE_SIZE;
|
|
}
|
|
}
|
|
|
|
static inline unsigned long memcg_page_state_output(struct mem_cgroup *memcg,
|
|
int item)
|
|
{
|
|
return memcg_page_state(memcg, item) * memcg_page_state_unit(item);
|
|
}
|
|
|
|
static char *memory_stat_format(struct mem_cgroup *memcg)
|
|
{
|
|
struct seq_buf s;
|
|
int i;
|
|
|
|
seq_buf_init(&s, kmalloc(PAGE_SIZE, GFP_KERNEL), PAGE_SIZE);
|
|
if (!s.buffer)
|
|
return NULL;
|
|
|
|
/*
|
|
* Provide statistics on the state of the memory subsystem as
|
|
* well as cumulative event counters that show past behavior.
|
|
*
|
|
* This list is ordered following a combination of these gradients:
|
|
* 1) generic big picture -> specifics and details
|
|
* 2) reflecting userspace activity -> reflecting kernel heuristics
|
|
*
|
|
* Current memory state:
|
|
*/
|
|
cgroup_rstat_flush(memcg->css.cgroup);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memory_stats); i++) {
|
|
u64 size;
|
|
|
|
size = memcg_page_state_output(memcg, memory_stats[i].idx);
|
|
seq_buf_printf(&s, "%s %llu\n", memory_stats[i].name, size);
|
|
|
|
if (unlikely(memory_stats[i].idx == NR_SLAB_UNRECLAIMABLE_B)) {
|
|
size += memcg_page_state_output(memcg,
|
|
NR_SLAB_RECLAIMABLE_B);
|
|
seq_buf_printf(&s, "slab %llu\n", size);
|
|
}
|
|
}
|
|
|
|
/* Accumulated memory events */
|
|
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGFAULT),
|
|
memcg_events(memcg, PGFAULT));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGMAJFAULT),
|
|
memcg_events(memcg, PGMAJFAULT));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGREFILL),
|
|
memcg_events(memcg, PGREFILL));
|
|
seq_buf_printf(&s, "pgscan %lu\n",
|
|
memcg_events(memcg, PGSCAN_KSWAPD) +
|
|
memcg_events(memcg, PGSCAN_DIRECT));
|
|
seq_buf_printf(&s, "pgsteal %lu\n",
|
|
memcg_events(memcg, PGSTEAL_KSWAPD) +
|
|
memcg_events(memcg, PGSTEAL_DIRECT));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGACTIVATE),
|
|
memcg_events(memcg, PGACTIVATE));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGDEACTIVATE),
|
|
memcg_events(memcg, PGDEACTIVATE));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREE),
|
|
memcg_events(memcg, PGLAZYFREE));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(PGLAZYFREED),
|
|
memcg_events(memcg, PGLAZYFREED));
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_FAULT_ALLOC),
|
|
memcg_events(memcg, THP_FAULT_ALLOC));
|
|
seq_buf_printf(&s, "%s %lu\n", vm_event_name(THP_COLLAPSE_ALLOC),
|
|
memcg_events(memcg, THP_COLLAPSE_ALLOC));
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
/* The above should easily fit into one page */
|
|
WARN_ON_ONCE(seq_buf_has_overflowed(&s));
|
|
|
|
return s.buffer;
|
|
}
|
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10))
|
|
/**
|
|
* mem_cgroup_print_oom_context: Print OOM information relevant to
|
|
* memory controller.
|
|
* @memcg: The memory cgroup that went over limit
|
|
* @p: Task that is going to be killed
|
|
*
|
|
* NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
|
|
* enabled
|
|
*/
|
|
void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p)
|
|
{
|
|
rcu_read_lock();
|
|
|
|
if (memcg) {
|
|
pr_cont(",oom_memcg=");
|
|
pr_cont_cgroup_path(memcg->css.cgroup);
|
|
} else
|
|
pr_cont(",global_oom");
|
|
if (p) {
|
|
pr_cont(",task_memcg=");
|
|
pr_cont_cgroup_path(task_cgroup(p, memory_cgrp_id));
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_print_oom_meminfo: Print OOM memory information relevant to
|
|
* memory controller.
|
|
* @memcg: The memory cgroup that went over limit
|
|
*/
|
|
void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
|
|
{
|
|
char *buf;
|
|
|
|
pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->memory)),
|
|
K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt);
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->swap)),
|
|
K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt);
|
|
else {
|
|
pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->memsw)),
|
|
K((u64)memcg->memsw.max), memcg->memsw.failcnt);
|
|
pr_info("kmem: usage %llukB, limit %llukB, failcnt %lu\n",
|
|
K((u64)page_counter_read(&memcg->kmem)),
|
|
K((u64)memcg->kmem.max), memcg->kmem.failcnt);
|
|
}
|
|
|
|
pr_info("Memory cgroup stats for ");
|
|
pr_cont_cgroup_path(memcg->css.cgroup);
|
|
pr_cont(":");
|
|
buf = memory_stat_format(memcg);
|
|
if (!buf)
|
|
return;
|
|
pr_info("%s", buf);
|
|
kfree(buf);
|
|
}
|
|
|
|
/*
|
|
* Return the memory (and swap, if configured) limit for a memcg.
|
|
*/
|
|
unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long max = READ_ONCE(memcg->memory.max);
|
|
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
|
|
if (mem_cgroup_swappiness(memcg))
|
|
max += min(READ_ONCE(memcg->swap.max),
|
|
(unsigned long)total_swap_pages);
|
|
} else { /* v1 */
|
|
if (mem_cgroup_swappiness(memcg)) {
|
|
/* Calculate swap excess capacity from memsw limit */
|
|
unsigned long swap = READ_ONCE(memcg->memsw.max) - max;
|
|
|
|
max += min(swap, (unsigned long)total_swap_pages);
|
|
}
|
|
}
|
|
return max;
|
|
}
|
|
|
|
unsigned long mem_cgroup_size(struct mem_cgroup *memcg)
|
|
{
|
|
return page_counter_read(&memcg->memory);
|
|
}
|
|
|
|
static bool mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
int order)
|
|
{
|
|
struct oom_control oc = {
|
|
.zonelist = NULL,
|
|
.nodemask = NULL,
|
|
.memcg = memcg,
|
|
.gfp_mask = gfp_mask,
|
|
.order = order,
|
|
};
|
|
bool ret = true;
|
|
|
|
if (mutex_lock_killable(&oom_lock))
|
|
return true;
|
|
|
|
if (mem_cgroup_margin(memcg) >= (1 << order))
|
|
goto unlock;
|
|
|
|
/*
|
|
* A few threads which were not waiting at mutex_lock_killable() can
|
|
* fail to bail out. Therefore, check again after holding oom_lock.
|
|
*/
|
|
ret = should_force_charge() || out_of_memory(&oc);
|
|
|
|
unlock:
|
|
mutex_unlock(&oom_lock);
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
|
|
pg_data_t *pgdat,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
struct mem_cgroup *victim = NULL;
|
|
int total = 0;
|
|
int loop = 0;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
struct mem_cgroup_reclaim_cookie reclaim = {
|
|
.pgdat = pgdat,
|
|
};
|
|
|
|
excess = soft_limit_excess(root_memcg);
|
|
|
|
while (1) {
|
|
victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
|
|
if (!victim) {
|
|
loop++;
|
|
if (loop >= 2) {
|
|
/*
|
|
* If we have not been able to reclaim
|
|
* anything, it might because there are
|
|
* no reclaimable pages under this hierarchy
|
|
*/
|
|
if (!total)
|
|
break;
|
|
/*
|
|
* We want to do more targeted reclaim.
|
|
* excess >> 2 is not to excessive so as to
|
|
* reclaim too much, nor too less that we keep
|
|
* coming back to reclaim from this cgroup
|
|
*/
|
|
if (total >= (excess >> 2) ||
|
|
(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
total += mem_cgroup_shrink_node(victim, gfp_mask, false,
|
|
pgdat, &nr_scanned);
|
|
*total_scanned += nr_scanned;
|
|
if (!soft_limit_excess(root_memcg))
|
|
break;
|
|
}
|
|
mem_cgroup_iter_break(root_memcg, victim);
|
|
return total;
|
|
}
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
static struct lockdep_map memcg_oom_lock_dep_map = {
|
|
.name = "memcg_oom_lock",
|
|
};
|
|
#endif
|
|
|
|
static DEFINE_SPINLOCK(memcg_oom_lock);
|
|
|
|
/*
|
|
* Check OOM-Killer is already running under our hierarchy.
|
|
* If someone is running, return false.
|
|
*/
|
|
static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter, *failed = NULL;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter->oom_lock) {
|
|
/*
|
|
* this subtree of our hierarchy is already locked
|
|
* so we cannot give a lock.
|
|
*/
|
|
failed = iter;
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
} else
|
|
iter->oom_lock = true;
|
|
}
|
|
|
|
if (failed) {
|
|
/*
|
|
* OK, we failed to lock the whole subtree so we have
|
|
* to clean up what we set up to the failing subtree
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter == failed) {
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
}
|
|
iter->oom_lock = false;
|
|
}
|
|
} else
|
|
mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return !failed;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
mutex_release(&memcg_oom_lock_dep_map, _RET_IP_);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->oom_lock = false;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->under_oom++;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
/*
|
|
* Be careful about under_oom underflows because a child memcg
|
|
* could have been added after mem_cgroup_mark_under_oom.
|
|
*/
|
|
spin_lock(&memcg_oom_lock);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
if (iter->under_oom > 0)
|
|
iter->under_oom--;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
|
|
|
|
struct oom_wait_info {
|
|
struct mem_cgroup *memcg;
|
|
wait_queue_entry_t wait;
|
|
};
|
|
|
|
static int memcg_oom_wake_function(wait_queue_entry_t *wait,
|
|
unsigned mode, int sync, void *arg)
|
|
{
|
|
struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
|
|
struct mem_cgroup *oom_wait_memcg;
|
|
struct oom_wait_info *oom_wait_info;
|
|
|
|
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
|
|
oom_wait_memcg = oom_wait_info->memcg;
|
|
|
|
if (!mem_cgroup_is_descendant(wake_memcg, oom_wait_memcg) &&
|
|
!mem_cgroup_is_descendant(oom_wait_memcg, wake_memcg))
|
|
return 0;
|
|
return autoremove_wake_function(wait, mode, sync, arg);
|
|
}
|
|
|
|
static void memcg_oom_recover(struct mem_cgroup *memcg)
|
|
{
|
|
/*
|
|
* For the following lockless ->under_oom test, the only required
|
|
* guarantee is that it must see the state asserted by an OOM when
|
|
* this function is called as a result of userland actions
|
|
* triggered by the notification of the OOM. This is trivially
|
|
* achieved by invoking mem_cgroup_mark_under_oom() before
|
|
* triggering notification.
|
|
*/
|
|
if (memcg && memcg->under_oom)
|
|
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
|
|
}
|
|
|
|
enum oom_status {
|
|
OOM_SUCCESS,
|
|
OOM_FAILED,
|
|
OOM_ASYNC,
|
|
OOM_SKIPPED
|
|
};
|
|
|
|
static enum oom_status mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
|
|
{
|
|
enum oom_status ret;
|
|
bool locked;
|
|
|
|
if (order > PAGE_ALLOC_COSTLY_ORDER)
|
|
return OOM_SKIPPED;
|
|
|
|
memcg_memory_event(memcg, MEMCG_OOM);
|
|
|
|
/*
|
|
* We are in the middle of the charge context here, so we
|
|
* don't want to block when potentially sitting on a callstack
|
|
* that holds all kinds of filesystem and mm locks.
|
|
*
|
|
* cgroup1 allows disabling the OOM killer and waiting for outside
|
|
* handling until the charge can succeed; remember the context and put
|
|
* the task to sleep at the end of the page fault when all locks are
|
|
* released.
|
|
*
|
|
* On the other hand, in-kernel OOM killer allows for an async victim
|
|
* memory reclaim (oom_reaper) and that means that we are not solely
|
|
* relying on the oom victim to make a forward progress and we can
|
|
* invoke the oom killer here.
|
|
*
|
|
* Please note that mem_cgroup_out_of_memory might fail to find a
|
|
* victim and then we have to bail out from the charge path.
|
|
*/
|
|
if (memcg->oom_kill_disable) {
|
|
if (!current->in_user_fault)
|
|
return OOM_SKIPPED;
|
|
css_get(&memcg->css);
|
|
current->memcg_in_oom = memcg;
|
|
current->memcg_oom_gfp_mask = mask;
|
|
current->memcg_oom_order = order;
|
|
|
|
return OOM_ASYNC;
|
|
}
|
|
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
locked = mem_cgroup_oom_trylock(memcg);
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
if (mem_cgroup_out_of_memory(memcg, mask, order))
|
|
ret = OOM_SUCCESS;
|
|
else
|
|
ret = OOM_FAILED;
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_unlock(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_oom_synchronize - complete memcg OOM handling
|
|
* @handle: actually kill/wait or just clean up the OOM state
|
|
*
|
|
* This has to be called at the end of a page fault if the memcg OOM
|
|
* handler was enabled.
|
|
*
|
|
* Memcg supports userspace OOM handling where failed allocations must
|
|
* sleep on a waitqueue until the userspace task resolves the
|
|
* situation. Sleeping directly in the charge context with all kinds
|
|
* of locks held is not a good idea, instead we remember an OOM state
|
|
* in the task and mem_cgroup_oom_synchronize() has to be called at
|
|
* the end of the page fault to complete the OOM handling.
|
|
*
|
|
* Returns %true if an ongoing memcg OOM situation was detected and
|
|
* completed, %false otherwise.
|
|
*/
|
|
bool mem_cgroup_oom_synchronize(bool handle)
|
|
{
|
|
struct mem_cgroup *memcg = current->memcg_in_oom;
|
|
struct oom_wait_info owait;
|
|
bool locked;
|
|
|
|
/* OOM is global, do not handle */
|
|
if (!memcg)
|
|
return false;
|
|
|
|
if (!handle)
|
|
goto cleanup;
|
|
|
|
owait.memcg = memcg;
|
|
owait.wait.flags = 0;
|
|
owait.wait.func = memcg_oom_wake_function;
|
|
owait.wait.private = current;
|
|
INIT_LIST_HEAD(&owait.wait.entry);
|
|
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
locked = mem_cgroup_oom_trylock(memcg);
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
|
|
if (locked && !memcg->oom_kill_disable) {
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
mem_cgroup_out_of_memory(memcg, current->memcg_oom_gfp_mask,
|
|
current->memcg_oom_order);
|
|
} else {
|
|
schedule();
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
}
|
|
|
|
if (locked) {
|
|
mem_cgroup_oom_unlock(memcg);
|
|
/*
|
|
* There is no guarantee that an OOM-lock contender
|
|
* sees the wakeups triggered by the OOM kill
|
|
* uncharges. Wake any sleepers explicitly.
|
|
*/
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
cleanup:
|
|
current->memcg_in_oom = NULL;
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_get_oom_group - get a memory cgroup to clean up after OOM
|
|
* @victim: task to be killed by the OOM killer
|
|
* @oom_domain: memcg in case of memcg OOM, NULL in case of system-wide OOM
|
|
*
|
|
* Returns a pointer to a memory cgroup, which has to be cleaned up
|
|
* by killing all belonging OOM-killable tasks.
|
|
*
|
|
* Caller has to call mem_cgroup_put() on the returned non-NULL memcg.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_get_oom_group(struct task_struct *victim,
|
|
struct mem_cgroup *oom_domain)
|
|
{
|
|
struct mem_cgroup *oom_group = NULL;
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return NULL;
|
|
|
|
if (!oom_domain)
|
|
oom_domain = root_mem_cgroup;
|
|
|
|
rcu_read_lock();
|
|
|
|
memcg = mem_cgroup_from_task(victim);
|
|
if (memcg == root_mem_cgroup)
|
|
goto out;
|
|
|
|
/*
|
|
* If the victim task has been asynchronously moved to a different
|
|
* memory cgroup, we might end up killing tasks outside oom_domain.
|
|
* In this case it's better to ignore memory.group.oom.
|
|
*/
|
|
if (unlikely(!mem_cgroup_is_descendant(memcg, oom_domain)))
|
|
goto out;
|
|
|
|
/*
|
|
* Traverse the memory cgroup hierarchy from the victim task's
|
|
* cgroup up to the OOMing cgroup (or root) to find the
|
|
* highest-level memory cgroup with oom.group set.
|
|
*/
|
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) {
|
|
if (memcg->oom_group)
|
|
oom_group = memcg;
|
|
|
|
if (memcg == oom_domain)
|
|
break;
|
|
}
|
|
|
|
if (oom_group)
|
|
css_get(&oom_group->css);
|
|
out:
|
|
rcu_read_unlock();
|
|
|
|
return oom_group;
|
|
}
|
|
|
|
void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
|
|
{
|
|
pr_info("Tasks in ");
|
|
pr_cont_cgroup_path(memcg->css.cgroup);
|
|
pr_cont(" are going to be killed due to memory.oom.group set\n");
|
|
}
|
|
|
|
/**
|
|
* lock_page_memcg - lock a page and memcg binding
|
|
* @page: the page
|
|
*
|
|
* This function protects unlocked LRU pages from being moved to
|
|
* another cgroup.
|
|
*
|
|
* It ensures lifetime of the locked memcg. Caller is responsible
|
|
* for the lifetime of the page.
|
|
*/
|
|
void lock_page_memcg(struct page *page)
|
|
{
|
|
struct page *head = compound_head(page); /* rmap on tail pages */
|
|
struct mem_cgroup *memcg;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* The RCU lock is held throughout the transaction. The fast
|
|
* path can get away without acquiring the memcg->move_lock
|
|
* because page moving starts with an RCU grace period.
|
|
*/
|
|
rcu_read_lock();
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
again:
|
|
memcg = page_memcg(head);
|
|
if (unlikely(!memcg))
|
|
return;
|
|
|
|
#ifdef CONFIG_PROVE_LOCKING
|
|
local_irq_save(flags);
|
|
might_lock(&memcg->move_lock);
|
|
local_irq_restore(flags);
|
|
#endif
|
|
|
|
if (atomic_read(&memcg->moving_account) <= 0)
|
|
return;
|
|
|
|
spin_lock_irqsave(&memcg->move_lock, flags);
|
|
if (memcg != page_memcg(head)) {
|
|
spin_unlock_irqrestore(&memcg->move_lock, flags);
|
|
goto again;
|
|
}
|
|
|
|
/*
|
|
* When charge migration first begins, we can have multiple
|
|
* critical sections holding the fast-path RCU lock and one
|
|
* holding the slowpath move_lock. Track the task who has the
|
|
* move_lock for unlock_page_memcg().
|
|
*/
|
|
memcg->move_lock_task = current;
|
|
memcg->move_lock_flags = flags;
|
|
}
|
|
EXPORT_SYMBOL(lock_page_memcg);
|
|
|
|
static void __unlock_page_memcg(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg && memcg->move_lock_task == current) {
|
|
unsigned long flags = memcg->move_lock_flags;
|
|
|
|
memcg->move_lock_task = NULL;
|
|
memcg->move_lock_flags = 0;
|
|
|
|
spin_unlock_irqrestore(&memcg->move_lock, flags);
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* unlock_page_memcg - unlock a page and memcg binding
|
|
* @page: the page
|
|
*/
|
|
void unlock_page_memcg(struct page *page)
|
|
{
|
|
struct page *head = compound_head(page);
|
|
|
|
__unlock_page_memcg(page_memcg(head));
|
|
}
|
|
EXPORT_SYMBOL(unlock_page_memcg);
|
|
|
|
struct obj_stock {
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
struct obj_cgroup *cached_objcg;
|
|
struct pglist_data *cached_pgdat;
|
|
unsigned int nr_bytes;
|
|
int nr_slab_reclaimable_b;
|
|
int nr_slab_unreclaimable_b;
|
|
#else
|
|
int dummy[0];
|
|
#endif
|
|
};
|
|
|
|
struct memcg_stock_pcp {
|
|
struct mem_cgroup *cached; /* this never be root cgroup */
|
|
unsigned int nr_pages;
|
|
struct obj_stock task_obj;
|
|
struct obj_stock irq_obj;
|
|
|
|
struct work_struct work;
|
|
unsigned long flags;
|
|
#define FLUSHING_CACHED_CHARGE 0
|
|
};
|
|
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
|
|
static DEFINE_MUTEX(percpu_charge_mutex);
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static void drain_obj_stock(struct obj_stock *stock);
|
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
|
|
struct mem_cgroup *root_memcg);
|
|
|
|
#else
|
|
static inline void drain_obj_stock(struct obj_stock *stock)
|
|
{
|
|
}
|
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
|
|
struct mem_cgroup *root_memcg)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Most kmem_cache_alloc() calls are from user context. The irq disable/enable
|
|
* sequence used in this case to access content from object stock is slow.
|
|
* To optimize for user context access, there are now two object stocks for
|
|
* task context and interrupt context access respectively.
|
|
*
|
|
* The task context object stock can be accessed by disabling preemption only
|
|
* which is cheap in non-preempt kernel. The interrupt context object stock
|
|
* can only be accessed after disabling interrupt. User context code can
|
|
* access interrupt object stock, but not vice versa.
|
|
*/
|
|
static inline struct obj_stock *get_obj_stock(unsigned long *pflags)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
|
|
if (likely(in_task())) {
|
|
*pflags = 0UL;
|
|
preempt_disable();
|
|
stock = this_cpu_ptr(&memcg_stock);
|
|
return &stock->task_obj;
|
|
}
|
|
|
|
local_irq_save(*pflags);
|
|
stock = this_cpu_ptr(&memcg_stock);
|
|
return &stock->irq_obj;
|
|
}
|
|
|
|
static inline void put_obj_stock(unsigned long flags)
|
|
{
|
|
if (likely(in_task()))
|
|
preempt_enable();
|
|
else
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/**
|
|
* consume_stock: Try to consume stocked charge on this cpu.
|
|
* @memcg: memcg to consume from.
|
|
* @nr_pages: how many pages to charge.
|
|
*
|
|
* The charges will only happen if @memcg matches the current cpu's memcg
|
|
* stock, and at least @nr_pages are available in that stock. Failure to
|
|
* service an allocation will refill the stock.
|
|
*
|
|
* returns true if successful, false otherwise.
|
|
*/
|
|
static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
unsigned long flags;
|
|
bool ret = false;
|
|
|
|
if (nr_pages > MEMCG_CHARGE_BATCH)
|
|
return ret;
|
|
|
|
local_irq_save(flags);
|
|
|
|
stock = this_cpu_ptr(&memcg_stock);
|
|
if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
|
|
stock->nr_pages -= nr_pages;
|
|
ret = true;
|
|
}
|
|
|
|
local_irq_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns stocks cached in percpu and reset cached information.
|
|
*/
|
|
static void drain_stock(struct memcg_stock_pcp *stock)
|
|
{
|
|
struct mem_cgroup *old = stock->cached;
|
|
|
|
if (!old)
|
|
return;
|
|
|
|
if (stock->nr_pages) {
|
|
page_counter_uncharge(&old->memory, stock->nr_pages);
|
|
if (do_memsw_account())
|
|
page_counter_uncharge(&old->memsw, stock->nr_pages);
|
|
stock->nr_pages = 0;
|
|
}
|
|
|
|
css_put(&old->css);
|
|
stock->cached = NULL;
|
|
}
|
|
|
|
static void drain_local_stock(struct work_struct *dummy)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs.
|
|
* drain_stock races is that we always operate on local CPU stock
|
|
* here with IRQ disabled
|
|
*/
|
|
local_irq_save(flags);
|
|
|
|
stock = this_cpu_ptr(&memcg_stock);
|
|
drain_obj_stock(&stock->irq_obj);
|
|
if (in_task())
|
|
drain_obj_stock(&stock->task_obj);
|
|
drain_stock(stock);
|
|
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/*
|
|
* Cache charges(val) to local per_cpu area.
|
|
* This will be consumed by consume_stock() function, later.
|
|
*/
|
|
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
|
|
stock = this_cpu_ptr(&memcg_stock);
|
|
if (stock->cached != memcg) { /* reset if necessary */
|
|
drain_stock(stock);
|
|
css_get(&memcg->css);
|
|
stock->cached = memcg;
|
|
}
|
|
stock->nr_pages += nr_pages;
|
|
|
|
if (stock->nr_pages > MEMCG_CHARGE_BATCH)
|
|
drain_stock(stock);
|
|
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/*
|
|
* Drains all per-CPU charge caches for given root_memcg resp. subtree
|
|
* of the hierarchy under it.
|
|
*/
|
|
static void drain_all_stock(struct mem_cgroup *root_memcg)
|
|
{
|
|
int cpu, curcpu;
|
|
|
|
/* If someone's already draining, avoid adding running more workers. */
|
|
if (!mutex_trylock(&percpu_charge_mutex))
|
|
return;
|
|
/*
|
|
* Notify other cpus that system-wide "drain" is running
|
|
* We do not care about races with the cpu hotplug because cpu down
|
|
* as well as workers from this path always operate on the local
|
|
* per-cpu data. CPU up doesn't touch memcg_stock at all.
|
|
*/
|
|
curcpu = get_cpu();
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
struct mem_cgroup *memcg;
|
|
bool flush = false;
|
|
|
|
rcu_read_lock();
|
|
memcg = stock->cached;
|
|
if (memcg && stock->nr_pages &&
|
|
mem_cgroup_is_descendant(memcg, root_memcg))
|
|
flush = true;
|
|
else if (obj_stock_flush_required(stock, root_memcg))
|
|
flush = true;
|
|
rcu_read_unlock();
|
|
|
|
if (flush &&
|
|
!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
|
|
if (cpu == curcpu)
|
|
drain_local_stock(&stock->work);
|
|
else
|
|
schedule_work_on(cpu, &stock->work);
|
|
}
|
|
}
|
|
put_cpu();
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
static int memcg_hotplug_cpu_dead(unsigned int cpu)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
|
|
stock = &per_cpu(memcg_stock, cpu);
|
|
drain_stock(stock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long reclaim_high(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages,
|
|
gfp_t gfp_mask)
|
|
{
|
|
unsigned long nr_reclaimed = 0;
|
|
|
|
do {
|
|
unsigned long pflags;
|
|
|
|
if (page_counter_read(&memcg->memory) <=
|
|
READ_ONCE(memcg->memory.high))
|
|
continue;
|
|
|
|
memcg_memory_event(memcg, MEMCG_HIGH);
|
|
|
|
psi_memstall_enter(&pflags);
|
|
nr_reclaimed += try_to_free_mem_cgroup_pages(memcg, nr_pages,
|
|
gfp_mask, true);
|
|
psi_memstall_leave(&pflags);
|
|
} while ((memcg = parent_mem_cgroup(memcg)) &&
|
|
!mem_cgroup_is_root(memcg));
|
|
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
static void high_work_func(struct work_struct *work)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = container_of(work, struct mem_cgroup, high_work);
|
|
reclaim_high(memcg, MEMCG_CHARGE_BATCH, GFP_KERNEL);
|
|
}
|
|
|
|
/*
|
|
* Clamp the maximum sleep time per allocation batch to 2 seconds. This is
|
|
* enough to still cause a significant slowdown in most cases, while still
|
|
* allowing diagnostics and tracing to proceed without becoming stuck.
|
|
*/
|
|
#define MEMCG_MAX_HIGH_DELAY_JIFFIES (2UL*HZ)
|
|
|
|
/*
|
|
* When calculating the delay, we use these either side of the exponentiation to
|
|
* maintain precision and scale to a reasonable number of jiffies (see the table
|
|
* below.
|
|
*
|
|
* - MEMCG_DELAY_PRECISION_SHIFT: Extra precision bits while translating the
|
|
* overage ratio to a delay.
|
|
* - MEMCG_DELAY_SCALING_SHIFT: The number of bits to scale down the
|
|
* proposed penalty in order to reduce to a reasonable number of jiffies, and
|
|
* to produce a reasonable delay curve.
|
|
*
|
|
* MEMCG_DELAY_SCALING_SHIFT just happens to be a number that produces a
|
|
* reasonable delay curve compared to precision-adjusted overage, not
|
|
* penalising heavily at first, but still making sure that growth beyond the
|
|
* limit penalises misbehaviour cgroups by slowing them down exponentially. For
|
|
* example, with a high of 100 megabytes:
|
|
*
|
|
* +-------+------------------------+
|
|
* | usage | time to allocate in ms |
|
|
* +-------+------------------------+
|
|
* | 100M | 0 |
|
|
* | 101M | 6 |
|
|
* | 102M | 25 |
|
|
* | 103M | 57 |
|
|
* | 104M | 102 |
|
|
* | 105M | 159 |
|
|
* | 106M | 230 |
|
|
* | 107M | 313 |
|
|
* | 108M | 409 |
|
|
* | 109M | 518 |
|
|
* | 110M | 639 |
|
|
* | 111M | 774 |
|
|
* | 112M | 921 |
|
|
* | 113M | 1081 |
|
|
* | 114M | 1254 |
|
|
* | 115M | 1439 |
|
|
* | 116M | 1638 |
|
|
* | 117M | 1849 |
|
|
* | 118M | 2000 |
|
|
* | 119M | 2000 |
|
|
* | 120M | 2000 |
|
|
* +-------+------------------------+
|
|
*/
|
|
#define MEMCG_DELAY_PRECISION_SHIFT 20
|
|
#define MEMCG_DELAY_SCALING_SHIFT 14
|
|
|
|
static u64 calculate_overage(unsigned long usage, unsigned long high)
|
|
{
|
|
u64 overage;
|
|
|
|
if (usage <= high)
|
|
return 0;
|
|
|
|
/*
|
|
* Prevent division by 0 in overage calculation by acting as if
|
|
* it was a threshold of 1 page
|
|
*/
|
|
high = max(high, 1UL);
|
|
|
|
overage = usage - high;
|
|
overage <<= MEMCG_DELAY_PRECISION_SHIFT;
|
|
return div64_u64(overage, high);
|
|
}
|
|
|
|
static u64 mem_find_max_overage(struct mem_cgroup *memcg)
|
|
{
|
|
u64 overage, max_overage = 0;
|
|
|
|
do {
|
|
overage = calculate_overage(page_counter_read(&memcg->memory),
|
|
READ_ONCE(memcg->memory.high));
|
|
max_overage = max(overage, max_overage);
|
|
} while ((memcg = parent_mem_cgroup(memcg)) &&
|
|
!mem_cgroup_is_root(memcg));
|
|
|
|
return max_overage;
|
|
}
|
|
|
|
static u64 swap_find_max_overage(struct mem_cgroup *memcg)
|
|
{
|
|
u64 overage, max_overage = 0;
|
|
|
|
do {
|
|
overage = calculate_overage(page_counter_read(&memcg->swap),
|
|
READ_ONCE(memcg->swap.high));
|
|
if (overage)
|
|
memcg_memory_event(memcg, MEMCG_SWAP_HIGH);
|
|
max_overage = max(overage, max_overage);
|
|
} while ((memcg = parent_mem_cgroup(memcg)) &&
|
|
!mem_cgroup_is_root(memcg));
|
|
|
|
return max_overage;
|
|
}
|
|
|
|
/*
|
|
* Get the number of jiffies that we should penalise a mischievous cgroup which
|
|
* is exceeding its memory.high by checking both it and its ancestors.
|
|
*/
|
|
static unsigned long calculate_high_delay(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages,
|
|
u64 max_overage)
|
|
{
|
|
unsigned long penalty_jiffies;
|
|
|
|
if (!max_overage)
|
|
return 0;
|
|
|
|
/*
|
|
* We use overage compared to memory.high to calculate the number of
|
|
* jiffies to sleep (penalty_jiffies). Ideally this value should be
|
|
* fairly lenient on small overages, and increasingly harsh when the
|
|
* memcg in question makes it clear that it has no intention of stopping
|
|
* its crazy behaviour, so we exponentially increase the delay based on
|
|
* overage amount.
|
|
*/
|
|
penalty_jiffies = max_overage * max_overage * HZ;
|
|
penalty_jiffies >>= MEMCG_DELAY_PRECISION_SHIFT;
|
|
penalty_jiffies >>= MEMCG_DELAY_SCALING_SHIFT;
|
|
|
|
/*
|
|
* Factor in the task's own contribution to the overage, such that four
|
|
* N-sized allocations are throttled approximately the same as one
|
|
* 4N-sized allocation.
|
|
*
|
|
* MEMCG_CHARGE_BATCH pages is nominal, so work out how much smaller or
|
|
* larger the current charge patch is than that.
|
|
*/
|
|
return penalty_jiffies * nr_pages / MEMCG_CHARGE_BATCH;
|
|
}
|
|
|
|
/*
|
|
* Scheduled by try_charge() to be executed from the userland return path
|
|
* and reclaims memory over the high limit.
|
|
*/
|
|
void mem_cgroup_handle_over_high(void)
|
|
{
|
|
unsigned long penalty_jiffies;
|
|
unsigned long pflags;
|
|
unsigned long nr_reclaimed;
|
|
unsigned int nr_pages = current->memcg_nr_pages_over_high;
|
|
int nr_retries = MAX_RECLAIM_RETRIES;
|
|
struct mem_cgroup *memcg;
|
|
bool in_retry = false;
|
|
|
|
if (likely(!nr_pages))
|
|
return;
|
|
|
|
memcg = get_mem_cgroup_from_mm(current->mm);
|
|
current->memcg_nr_pages_over_high = 0;
|
|
|
|
retry_reclaim:
|
|
/*
|
|
* The allocating task should reclaim at least the batch size, but for
|
|
* subsequent retries we only want to do what's necessary to prevent oom
|
|
* or breaching resource isolation.
|
|
*
|
|
* This is distinct from memory.max or page allocator behaviour because
|
|
* memory.high is currently batched, whereas memory.max and the page
|
|
* allocator run every time an allocation is made.
|
|
*/
|
|
nr_reclaimed = reclaim_high(memcg,
|
|
in_retry ? SWAP_CLUSTER_MAX : nr_pages,
|
|
GFP_KERNEL);
|
|
|
|
/*
|
|
* memory.high is breached and reclaim is unable to keep up. Throttle
|
|
* allocators proactively to slow down excessive growth.
|
|
*/
|
|
penalty_jiffies = calculate_high_delay(memcg, nr_pages,
|
|
mem_find_max_overage(memcg));
|
|
|
|
penalty_jiffies += calculate_high_delay(memcg, nr_pages,
|
|
swap_find_max_overage(memcg));
|
|
|
|
/*
|
|
* Clamp the max delay per usermode return so as to still keep the
|
|
* application moving forwards and also permit diagnostics, albeit
|
|
* extremely slowly.
|
|
*/
|
|
penalty_jiffies = min(penalty_jiffies, MEMCG_MAX_HIGH_DELAY_JIFFIES);
|
|
|
|
/*
|
|
* Don't sleep if the amount of jiffies this memcg owes us is so low
|
|
* that it's not even worth doing, in an attempt to be nice to those who
|
|
* go only a small amount over their memory.high value and maybe haven't
|
|
* been aggressively reclaimed enough yet.
|
|
*/
|
|
if (penalty_jiffies <= HZ / 100)
|
|
goto out;
|
|
|
|
/*
|
|
* If reclaim is making forward progress but we're still over
|
|
* memory.high, we want to encourage that rather than doing allocator
|
|
* throttling.
|
|
*/
|
|
if (nr_reclaimed || nr_retries--) {
|
|
in_retry = true;
|
|
goto retry_reclaim;
|
|
}
|
|
|
|
/*
|
|
* If we exit early, we're guaranteed to die (since
|
|
* schedule_timeout_killable sets TASK_KILLABLE). This means we don't
|
|
* need to account for any ill-begotten jiffies to pay them off later.
|
|
*/
|
|
psi_memstall_enter(&pflags);
|
|
schedule_timeout_killable(penalty_jiffies);
|
|
psi_memstall_leave(&pflags);
|
|
|
|
out:
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages)
|
|
{
|
|
unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages);
|
|
int nr_retries = MAX_RECLAIM_RETRIES;
|
|
struct mem_cgroup *mem_over_limit;
|
|
struct page_counter *counter;
|
|
enum oom_status oom_status;
|
|
unsigned long nr_reclaimed;
|
|
bool may_swap = true;
|
|
bool drained = false;
|
|
unsigned long pflags;
|
|
|
|
retry:
|
|
if (consume_stock(memcg, nr_pages))
|
|
return 0;
|
|
|
|
if (!do_memsw_account() ||
|
|
page_counter_try_charge(&memcg->memsw, batch, &counter)) {
|
|
if (page_counter_try_charge(&memcg->memory, batch, &counter))
|
|
goto done_restock;
|
|
if (do_memsw_account())
|
|
page_counter_uncharge(&memcg->memsw, batch);
|
|
mem_over_limit = mem_cgroup_from_counter(counter, memory);
|
|
} else {
|
|
mem_over_limit = mem_cgroup_from_counter(counter, memsw);
|
|
may_swap = false;
|
|
}
|
|
|
|
if (batch > nr_pages) {
|
|
batch = nr_pages;
|
|
goto retry;
|
|
}
|
|
|
|
/*
|
|
* Memcg doesn't have a dedicated reserve for atomic
|
|
* allocations. But like the global atomic pool, we need to
|
|
* put the burden of reclaim on regular allocation requests
|
|
* and let these go through as privileged allocations.
|
|
*/
|
|
if (gfp_mask & __GFP_ATOMIC)
|
|
goto force;
|
|
|
|
/*
|
|
* Unlike in global OOM situations, memcg is not in a physical
|
|
* memory shortage. Allow dying and OOM-killed tasks to
|
|
* bypass the last charges so that they can exit quickly and
|
|
* free their memory.
|
|
*/
|
|
if (unlikely(should_force_charge()))
|
|
goto force;
|
|
|
|
/*
|
|
* Prevent unbounded recursion when reclaim operations need to
|
|
* allocate memory. This might exceed the limits temporarily,
|
|
* but we prefer facilitating memory reclaim and getting back
|
|
* under the limit over triggering OOM kills in these cases.
|
|
*/
|
|
if (unlikely(current->flags & PF_MEMALLOC))
|
|
goto force;
|
|
|
|
if (unlikely(task_in_memcg_oom(current)))
|
|
goto nomem;
|
|
|
|
if (!gfpflags_allow_blocking(gfp_mask))
|
|
goto nomem;
|
|
|
|
memcg_memory_event(mem_over_limit, MEMCG_MAX);
|
|
|
|
psi_memstall_enter(&pflags);
|
|
nr_reclaimed = try_to_free_mem_cgroup_pages(mem_over_limit, nr_pages,
|
|
gfp_mask, may_swap);
|
|
psi_memstall_leave(&pflags);
|
|
|
|
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
|
|
goto retry;
|
|
|
|
if (!drained) {
|
|
drain_all_stock(mem_over_limit);
|
|
drained = true;
|
|
goto retry;
|
|
}
|
|
|
|
if (gfp_mask & __GFP_NORETRY)
|
|
goto nomem;
|
|
/*
|
|
* Even though the limit is exceeded at this point, reclaim
|
|
* may have been able to free some pages. Retry the charge
|
|
* before killing the task.
|
|
*
|
|
* Only for regular pages, though: huge pages are rather
|
|
* unlikely to succeed so close to the limit, and we fall back
|
|
* to regular pages anyway in case of failure.
|
|
*/
|
|
if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
|
|
goto retry;
|
|
/*
|
|
* At task move, charge accounts can be doubly counted. So, it's
|
|
* better to wait until the end of task_move if something is going on.
|
|
*/
|
|
if (mem_cgroup_wait_acct_move(mem_over_limit))
|
|
goto retry;
|
|
|
|
if (nr_retries--)
|
|
goto retry;
|
|
|
|
if (gfp_mask & __GFP_RETRY_MAYFAIL)
|
|
goto nomem;
|
|
|
|
if (fatal_signal_pending(current))
|
|
goto force;
|
|
|
|
/*
|
|
* keep retrying as long as the memcg oom killer is able to make
|
|
* a forward progress or bypass the charge if the oom killer
|
|
* couldn't make any progress.
|
|
*/
|
|
oom_status = mem_cgroup_oom(mem_over_limit, gfp_mask,
|
|
get_order(nr_pages * PAGE_SIZE));
|
|
switch (oom_status) {
|
|
case OOM_SUCCESS:
|
|
nr_retries = MAX_RECLAIM_RETRIES;
|
|
goto retry;
|
|
case OOM_FAILED:
|
|
goto force;
|
|
default:
|
|
goto nomem;
|
|
}
|
|
nomem:
|
|
if (!(gfp_mask & __GFP_NOFAIL))
|
|
return -ENOMEM;
|
|
force:
|
|
/*
|
|
* The allocation either can't fail or will lead to more memory
|
|
* being freed very soon. Allow memory usage go over the limit
|
|
* temporarily by force charging it.
|
|
*/
|
|
page_counter_charge(&memcg->memory, nr_pages);
|
|
if (do_memsw_account())
|
|
page_counter_charge(&memcg->memsw, nr_pages);
|
|
|
|
return 0;
|
|
|
|
done_restock:
|
|
if (batch > nr_pages)
|
|
refill_stock(memcg, batch - nr_pages);
|
|
|
|
/*
|
|
* If the hierarchy is above the normal consumption range, schedule
|
|
* reclaim on returning to userland. We can perform reclaim here
|
|
* if __GFP_RECLAIM but let's always punt for simplicity and so that
|
|
* GFP_KERNEL can consistently be used during reclaim. @memcg is
|
|
* not recorded as it most likely matches current's and won't
|
|
* change in the meantime. As high limit is checked again before
|
|
* reclaim, the cost of mismatch is negligible.
|
|
*/
|
|
do {
|
|
bool mem_high, swap_high;
|
|
|
|
mem_high = page_counter_read(&memcg->memory) >
|
|
READ_ONCE(memcg->memory.high);
|
|
swap_high = page_counter_read(&memcg->swap) >
|
|
READ_ONCE(memcg->swap.high);
|
|
|
|
/* Don't bother a random interrupted task */
|
|
if (in_interrupt()) {
|
|
if (mem_high) {
|
|
schedule_work(&memcg->high_work);
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (mem_high || swap_high) {
|
|
/*
|
|
* The allocating tasks in this cgroup will need to do
|
|
* reclaim or be throttled to prevent further growth
|
|
* of the memory or swap footprints.
|
|
*
|
|
* Target some best-effort fairness between the tasks,
|
|
* and distribute reclaim work and delay penalties
|
|
* based on how much each task is actually allocating.
|
|
*/
|
|
current->memcg_nr_pages_over_high += batch;
|
|
set_notify_resume(current);
|
|
break;
|
|
}
|
|
} while ((memcg = parent_mem_cgroup(memcg)));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages)
|
|
{
|
|
if (mem_cgroup_is_root(memcg))
|
|
return 0;
|
|
|
|
return try_charge_memcg(memcg, gfp_mask, nr_pages);
|
|
}
|
|
|
|
#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
|
|
static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
if (mem_cgroup_is_root(memcg))
|
|
return;
|
|
|
|
page_counter_uncharge(&memcg->memory, nr_pages);
|
|
if (do_memsw_account())
|
|
page_counter_uncharge(&memcg->memsw, nr_pages);
|
|
}
|
|
#endif
|
|
|
|
static void commit_charge(struct page *page, struct mem_cgroup *memcg)
|
|
{
|
|
VM_BUG_ON_PAGE(page_memcg(page), page);
|
|
/*
|
|
* Any of the following ensures page's memcg stability:
|
|
*
|
|
* - the page lock
|
|
* - LRU isolation
|
|
* - lock_page_memcg()
|
|
* - exclusive reference
|
|
*/
|
|
page->memcg_data = (unsigned long)memcg;
|
|
}
|
|
|
|
static struct mem_cgroup *get_mem_cgroup_from_objcg(struct obj_cgroup *objcg)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
rcu_read_lock();
|
|
retry:
|
|
memcg = obj_cgroup_memcg(objcg);
|
|
if (unlikely(!css_tryget(&memcg->css)))
|
|
goto retry;
|
|
rcu_read_unlock();
|
|
|
|
return memcg;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/*
|
|
* The allocated objcg pointers array is not accounted directly.
|
|
* Moreover, it should not come from DMA buffer and is not readily
|
|
* reclaimable. So those GFP bits should be masked off.
|
|
*/
|
|
#define OBJCGS_CLEAR_MASK (__GFP_DMA | __GFP_RECLAIMABLE | __GFP_ACCOUNT)
|
|
|
|
int memcg_alloc_page_obj_cgroups(struct page *page, struct kmem_cache *s,
|
|
gfp_t gfp, bool new_page)
|
|
{
|
|
unsigned int objects = objs_per_slab_page(s, page);
|
|
unsigned long memcg_data;
|
|
void *vec;
|
|
|
|
gfp &= ~OBJCGS_CLEAR_MASK;
|
|
vec = kcalloc_node(objects, sizeof(struct obj_cgroup *), gfp,
|
|
page_to_nid(page));
|
|
if (!vec)
|
|
return -ENOMEM;
|
|
|
|
memcg_data = (unsigned long) vec | MEMCG_DATA_OBJCGS;
|
|
if (new_page) {
|
|
/*
|
|
* If the slab page is brand new and nobody can yet access
|
|
* it's memcg_data, no synchronization is required and
|
|
* memcg_data can be simply assigned.
|
|
*/
|
|
page->memcg_data = memcg_data;
|
|
} else if (cmpxchg(&page->memcg_data, 0, memcg_data)) {
|
|
/*
|
|
* If the slab page is already in use, somebody can allocate
|
|
* and assign obj_cgroups in parallel. In this case the existing
|
|
* objcg vector should be reused.
|
|
*/
|
|
kfree(vec);
|
|
return 0;
|
|
}
|
|
|
|
kmemleak_not_leak(vec);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Returns a pointer to the memory cgroup to which the kernel object is charged.
|
|
*
|
|
* A passed kernel object can be a slab object or a generic kernel page, so
|
|
* different mechanisms for getting the memory cgroup pointer should be used.
|
|
* In certain cases (e.g. kernel stacks or large kmallocs with SLUB) the caller
|
|
* can not know for sure how the kernel object is implemented.
|
|
* mem_cgroup_from_obj() can be safely used in such cases.
|
|
*
|
|
* The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
|
|
* cgroup_mutex, etc.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_from_obj(void *p)
|
|
{
|
|
struct page *page;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
page = virt_to_head_page(p);
|
|
|
|
/*
|
|
* Slab objects are accounted individually, not per-page.
|
|
* Memcg membership data for each individual object is saved in
|
|
* the page->obj_cgroups.
|
|
*/
|
|
if (page_objcgs_check(page)) {
|
|
struct obj_cgroup *objcg;
|
|
unsigned int off;
|
|
|
|
off = obj_to_index(page->slab_cache, page, p);
|
|
objcg = page_objcgs(page)[off];
|
|
if (objcg)
|
|
return obj_cgroup_memcg(objcg);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* page_memcg_check() is used here, because page_has_obj_cgroups()
|
|
* check above could fail because the object cgroups vector wasn't set
|
|
* at that moment, but it can be set concurrently.
|
|
* page_memcg_check(page) will guarantee that a proper memory
|
|
* cgroup pointer or NULL will be returned.
|
|
*/
|
|
return page_memcg_check(page);
|
|
}
|
|
|
|
__always_inline struct obj_cgroup *get_obj_cgroup_from_current(void)
|
|
{
|
|
struct obj_cgroup *objcg = NULL;
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (memcg_kmem_bypass())
|
|
return NULL;
|
|
|
|
rcu_read_lock();
|
|
if (unlikely(active_memcg()))
|
|
memcg = active_memcg();
|
|
else
|
|
memcg = mem_cgroup_from_task(current);
|
|
|
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) {
|
|
objcg = rcu_dereference(memcg->objcg);
|
|
if (objcg && obj_cgroup_tryget(objcg))
|
|
break;
|
|
objcg = NULL;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
return objcg;
|
|
}
|
|
|
|
static int memcg_alloc_cache_id(void)
|
|
{
|
|
int id, size;
|
|
int err;
|
|
|
|
id = ida_simple_get(&memcg_cache_ida,
|
|
0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
|
|
if (id < 0)
|
|
return id;
|
|
|
|
if (id < memcg_nr_cache_ids)
|
|
return id;
|
|
|
|
/*
|
|
* There's no space for the new id in memcg_caches arrays,
|
|
* so we have to grow them.
|
|
*/
|
|
down_write(&memcg_cache_ids_sem);
|
|
|
|
size = 2 * (id + 1);
|
|
if (size < MEMCG_CACHES_MIN_SIZE)
|
|
size = MEMCG_CACHES_MIN_SIZE;
|
|
else if (size > MEMCG_CACHES_MAX_SIZE)
|
|
size = MEMCG_CACHES_MAX_SIZE;
|
|
|
|
err = memcg_update_all_list_lrus(size);
|
|
if (!err)
|
|
memcg_nr_cache_ids = size;
|
|
|
|
up_write(&memcg_cache_ids_sem);
|
|
|
|
if (err) {
|
|
ida_simple_remove(&memcg_cache_ida, id);
|
|
return err;
|
|
}
|
|
return id;
|
|
}
|
|
|
|
static void memcg_free_cache_id(int id)
|
|
{
|
|
ida_simple_remove(&memcg_cache_ida, id);
|
|
}
|
|
|
|
/*
|
|
* obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg
|
|
* @objcg: object cgroup to uncharge
|
|
* @nr_pages: number of pages to uncharge
|
|
*/
|
|
static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
|
|
unsigned int nr_pages)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = get_mem_cgroup_from_objcg(objcg);
|
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
page_counter_uncharge(&memcg->kmem, nr_pages);
|
|
refill_stock(memcg, nr_pages);
|
|
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* obj_cgroup_charge_pages: charge a number of kernel pages to a objcg
|
|
* @objcg: object cgroup to charge
|
|
* @gfp: reclaim mode
|
|
* @nr_pages: number of pages to charge
|
|
*
|
|
* Returns 0 on success, an error code on failure.
|
|
*/
|
|
static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
|
|
unsigned int nr_pages)
|
|
{
|
|
struct page_counter *counter;
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
memcg = get_mem_cgroup_from_objcg(objcg);
|
|
|
|
ret = try_charge_memcg(memcg, gfp, nr_pages);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) &&
|
|
!page_counter_try_charge(&memcg->kmem, nr_pages, &counter)) {
|
|
|
|
/*
|
|
* Enforce __GFP_NOFAIL allocation because callers are not
|
|
* prepared to see failures and likely do not have any failure
|
|
* handling code.
|
|
*/
|
|
if (gfp & __GFP_NOFAIL) {
|
|
page_counter_charge(&memcg->kmem, nr_pages);
|
|
goto out;
|
|
}
|
|
cancel_charge(memcg, nr_pages);
|
|
ret = -ENOMEM;
|
|
}
|
|
out:
|
|
css_put(&memcg->css);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup
|
|
* @page: page to charge
|
|
* @gfp: reclaim mode
|
|
* @order: allocation order
|
|
*
|
|
* Returns 0 on success, an error code on failure.
|
|
*/
|
|
int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
|
|
{
|
|
struct obj_cgroup *objcg;
|
|
int ret = 0;
|
|
|
|
objcg = get_obj_cgroup_from_current();
|
|
if (objcg) {
|
|
ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order);
|
|
if (!ret) {
|
|
page->memcg_data = (unsigned long)objcg |
|
|
MEMCG_DATA_KMEM;
|
|
return 0;
|
|
}
|
|
obj_cgroup_put(objcg);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __memcg_kmem_uncharge_page: uncharge a kmem page
|
|
* @page: page to uncharge
|
|
* @order: allocation order
|
|
*/
|
|
void __memcg_kmem_uncharge_page(struct page *page, int order)
|
|
{
|
|
struct obj_cgroup *objcg;
|
|
unsigned int nr_pages = 1 << order;
|
|
|
|
if (!PageMemcgKmem(page))
|
|
return;
|
|
|
|
objcg = __page_objcg(page);
|
|
obj_cgroup_uncharge_pages(objcg, nr_pages);
|
|
page->memcg_data = 0;
|
|
obj_cgroup_put(objcg);
|
|
}
|
|
|
|
void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
|
|
enum node_stat_item idx, int nr)
|
|
{
|
|
unsigned long flags;
|
|
struct obj_stock *stock = get_obj_stock(&flags);
|
|
int *bytes;
|
|
|
|
/*
|
|
* Save vmstat data in stock and skip vmstat array update unless
|
|
* accumulating over a page of vmstat data or when pgdat or idx
|
|
* changes.
|
|
*/
|
|
if (stock->cached_objcg != objcg) {
|
|
drain_obj_stock(stock);
|
|
obj_cgroup_get(objcg);
|
|
stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
|
|
? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
|
|
stock->cached_objcg = objcg;
|
|
stock->cached_pgdat = pgdat;
|
|
} else if (stock->cached_pgdat != pgdat) {
|
|
/* Flush the existing cached vmstat data */
|
|
struct pglist_data *oldpg = stock->cached_pgdat;
|
|
|
|
if (stock->nr_slab_reclaimable_b) {
|
|
mod_objcg_mlstate(objcg, oldpg, NR_SLAB_RECLAIMABLE_B,
|
|
stock->nr_slab_reclaimable_b);
|
|
stock->nr_slab_reclaimable_b = 0;
|
|
}
|
|
if (stock->nr_slab_unreclaimable_b) {
|
|
mod_objcg_mlstate(objcg, oldpg, NR_SLAB_UNRECLAIMABLE_B,
|
|
stock->nr_slab_unreclaimable_b);
|
|
stock->nr_slab_unreclaimable_b = 0;
|
|
}
|
|
stock->cached_pgdat = pgdat;
|
|
}
|
|
|
|
bytes = (idx == NR_SLAB_RECLAIMABLE_B) ? &stock->nr_slab_reclaimable_b
|
|
: &stock->nr_slab_unreclaimable_b;
|
|
/*
|
|
* Even for large object >= PAGE_SIZE, the vmstat data will still be
|
|
* cached locally at least once before pushing it out.
|
|
*/
|
|
if (!*bytes) {
|
|
*bytes = nr;
|
|
nr = 0;
|
|
} else {
|
|
*bytes += nr;
|
|
if (abs(*bytes) > PAGE_SIZE) {
|
|
nr = *bytes;
|
|
*bytes = 0;
|
|
} else {
|
|
nr = 0;
|
|
}
|
|
}
|
|
if (nr)
|
|
mod_objcg_mlstate(objcg, pgdat, idx, nr);
|
|
|
|
put_obj_stock(flags);
|
|
}
|
|
|
|
static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes)
|
|
{
|
|
unsigned long flags;
|
|
struct obj_stock *stock = get_obj_stock(&flags);
|
|
bool ret = false;
|
|
|
|
if (objcg == stock->cached_objcg && stock->nr_bytes >= nr_bytes) {
|
|
stock->nr_bytes -= nr_bytes;
|
|
ret = true;
|
|
}
|
|
|
|
put_obj_stock(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void drain_obj_stock(struct obj_stock *stock)
|
|
{
|
|
struct obj_cgroup *old = stock->cached_objcg;
|
|
|
|
if (!old)
|
|
return;
|
|
|
|
if (stock->nr_bytes) {
|
|
unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;
|
|
unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);
|
|
|
|
if (nr_pages)
|
|
obj_cgroup_uncharge_pages(old, nr_pages);
|
|
|
|
/*
|
|
* The leftover is flushed to the centralized per-memcg value.
|
|
* On the next attempt to refill obj stock it will be moved
|
|
* to a per-cpu stock (probably, on an other CPU), see
|
|
* refill_obj_stock().
|
|
*
|
|
* How often it's flushed is a trade-off between the memory
|
|
* limit enforcement accuracy and potential CPU contention,
|
|
* so it might be changed in the future.
|
|
*/
|
|
atomic_add(nr_bytes, &old->nr_charged_bytes);
|
|
stock->nr_bytes = 0;
|
|
}
|
|
|
|
/*
|
|
* Flush the vmstat data in current stock
|
|
*/
|
|
if (stock->nr_slab_reclaimable_b || stock->nr_slab_unreclaimable_b) {
|
|
if (stock->nr_slab_reclaimable_b) {
|
|
mod_objcg_mlstate(old, stock->cached_pgdat,
|
|
NR_SLAB_RECLAIMABLE_B,
|
|
stock->nr_slab_reclaimable_b);
|
|
stock->nr_slab_reclaimable_b = 0;
|
|
}
|
|
if (stock->nr_slab_unreclaimable_b) {
|
|
mod_objcg_mlstate(old, stock->cached_pgdat,
|
|
NR_SLAB_UNRECLAIMABLE_B,
|
|
stock->nr_slab_unreclaimable_b);
|
|
stock->nr_slab_unreclaimable_b = 0;
|
|
}
|
|
stock->cached_pgdat = NULL;
|
|
}
|
|
|
|
obj_cgroup_put(old);
|
|
stock->cached_objcg = NULL;
|
|
}
|
|
|
|
static bool obj_stock_flush_required(struct memcg_stock_pcp *stock,
|
|
struct mem_cgroup *root_memcg)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (in_task() && stock->task_obj.cached_objcg) {
|
|
memcg = obj_cgroup_memcg(stock->task_obj.cached_objcg);
|
|
if (memcg && mem_cgroup_is_descendant(memcg, root_memcg))
|
|
return true;
|
|
}
|
|
if (stock->irq_obj.cached_objcg) {
|
|
memcg = obj_cgroup_memcg(stock->irq_obj.cached_objcg);
|
|
if (memcg && mem_cgroup_is_descendant(memcg, root_memcg))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
|
|
bool allow_uncharge)
|
|
{
|
|
unsigned long flags;
|
|
struct obj_stock *stock = get_obj_stock(&flags);
|
|
unsigned int nr_pages = 0;
|
|
|
|
if (stock->cached_objcg != objcg) { /* reset if necessary */
|
|
drain_obj_stock(stock);
|
|
obj_cgroup_get(objcg);
|
|
stock->cached_objcg = objcg;
|
|
stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
|
|
? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
|
|
allow_uncharge = true; /* Allow uncharge when objcg changes */
|
|
}
|
|
stock->nr_bytes += nr_bytes;
|
|
|
|
if (allow_uncharge && (stock->nr_bytes > PAGE_SIZE)) {
|
|
nr_pages = stock->nr_bytes >> PAGE_SHIFT;
|
|
stock->nr_bytes &= (PAGE_SIZE - 1);
|
|
}
|
|
|
|
put_obj_stock(flags);
|
|
|
|
if (nr_pages)
|
|
obj_cgroup_uncharge_pages(objcg, nr_pages);
|
|
}
|
|
|
|
int obj_cgroup_charge(struct obj_cgroup *objcg, gfp_t gfp, size_t size)
|
|
{
|
|
unsigned int nr_pages, nr_bytes;
|
|
int ret;
|
|
|
|
if (consume_obj_stock(objcg, size))
|
|
return 0;
|
|
|
|
/*
|
|
* In theory, objcg->nr_charged_bytes can have enough
|
|
* pre-charged bytes to satisfy the allocation. However,
|
|
* flushing objcg->nr_charged_bytes requires two atomic
|
|
* operations, and objcg->nr_charged_bytes can't be big.
|
|
* The shared objcg->nr_charged_bytes can also become a
|
|
* performance bottleneck if all tasks of the same memcg are
|
|
* trying to update it. So it's better to ignore it and try
|
|
* grab some new pages. The stock's nr_bytes will be flushed to
|
|
* objcg->nr_charged_bytes later on when objcg changes.
|
|
*
|
|
* The stock's nr_bytes may contain enough pre-charged bytes
|
|
* to allow one less page from being charged, but we can't rely
|
|
* on the pre-charged bytes not being changed outside of
|
|
* consume_obj_stock() or refill_obj_stock(). So ignore those
|
|
* pre-charged bytes as well when charging pages. To avoid a
|
|
* page uncharge right after a page charge, we set the
|
|
* allow_uncharge flag to false when calling refill_obj_stock()
|
|
* to temporarily allow the pre-charged bytes to exceed the page
|
|
* size limit. The maximum reachable value of the pre-charged
|
|
* bytes is (sizeof(object) + PAGE_SIZE - 2) if there is no data
|
|
* race.
|
|
*/
|
|
nr_pages = size >> PAGE_SHIFT;
|
|
nr_bytes = size & (PAGE_SIZE - 1);
|
|
|
|
if (nr_bytes)
|
|
nr_pages += 1;
|
|
|
|
ret = obj_cgroup_charge_pages(objcg, gfp, nr_pages);
|
|
if (!ret && nr_bytes)
|
|
refill_obj_stock(objcg, PAGE_SIZE - nr_bytes, false);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
|
|
{
|
|
refill_obj_stock(objcg, size, true);
|
|
}
|
|
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
/*
|
|
* Because page_memcg(head) is not set on tails, set it now.
|
|
*/
|
|
void split_page_memcg(struct page *head, unsigned int nr)
|
|
{
|
|
struct mem_cgroup *memcg = page_memcg(head);
|
|
int i;
|
|
|
|
if (mem_cgroup_disabled() || !memcg)
|
|
return;
|
|
|
|
for (i = 1; i < nr; i++)
|
|
head[i].memcg_data = head->memcg_data;
|
|
|
|
if (PageMemcgKmem(head))
|
|
obj_cgroup_get_many(__page_objcg(head), nr - 1);
|
|
else
|
|
css_get_many(&memcg->css, nr - 1);
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
/**
|
|
* mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
|
|
* @entry: swap entry to be moved
|
|
* @from: mem_cgroup which the entry is moved from
|
|
* @to: mem_cgroup which the entry is moved to
|
|
*
|
|
* It succeeds only when the swap_cgroup's record for this entry is the same
|
|
* as the mem_cgroup's id of @from.
|
|
*
|
|
* Returns 0 on success, -EINVAL on failure.
|
|
*
|
|
* The caller must have charged to @to, IOW, called page_counter_charge() about
|
|
* both res and memsw, and called css_get().
|
|
*/
|
|
static int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
unsigned short old_id, new_id;
|
|
|
|
old_id = mem_cgroup_id(from);
|
|
new_id = mem_cgroup_id(to);
|
|
|
|
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
|
|
mod_memcg_state(from, MEMCG_SWAP, -1);
|
|
mod_memcg_state(to, MEMCG_SWAP, 1);
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
#else
|
|
static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
static DEFINE_MUTEX(memcg_max_mutex);
|
|
|
|
static int mem_cgroup_resize_max(struct mem_cgroup *memcg,
|
|
unsigned long max, bool memsw)
|
|
{
|
|
bool enlarge = false;
|
|
bool drained = false;
|
|
int ret;
|
|
bool limits_invariant;
|
|
struct page_counter *counter = memsw ? &memcg->memsw : &memcg->memory;
|
|
|
|
do {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
|
|
mutex_lock(&memcg_max_mutex);
|
|
/*
|
|
* Make sure that the new limit (memsw or memory limit) doesn't
|
|
* break our basic invariant rule memory.max <= memsw.max.
|
|
*/
|
|
limits_invariant = memsw ? max >= READ_ONCE(memcg->memory.max) :
|
|
max <= memcg->memsw.max;
|
|
if (!limits_invariant) {
|
|
mutex_unlock(&memcg_max_mutex);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
if (max > counter->max)
|
|
enlarge = true;
|
|
ret = page_counter_set_max(counter, max);
|
|
mutex_unlock(&memcg_max_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
if (!drained) {
|
|
drain_all_stock(memcg);
|
|
drained = true;
|
|
continue;
|
|
}
|
|
|
|
if (!try_to_free_mem_cgroup_pages(memcg, 1,
|
|
GFP_KERNEL, !memsw)) {
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
} while (true);
|
|
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
unsigned long nr_reclaimed = 0;
|
|
struct mem_cgroup_per_node *mz, *next_mz = NULL;
|
|
unsigned long reclaimed;
|
|
int loop = 0;
|
|
struct mem_cgroup_tree_per_node *mctz;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
|
|
if (order > 0)
|
|
return 0;
|
|
|
|
mctz = soft_limit_tree_node(pgdat->node_id);
|
|
|
|
/*
|
|
* Do not even bother to check the largest node if the root
|
|
* is empty. Do it lockless to prevent lock bouncing. Races
|
|
* are acceptable as soft limit is best effort anyway.
|
|
*/
|
|
if (!mctz || RB_EMPTY_ROOT(&mctz->rb_root))
|
|
return 0;
|
|
|
|
/*
|
|
* This loop can run a while, specially if mem_cgroup's continuously
|
|
* keep exceeding their soft limit and putting the system under
|
|
* pressure
|
|
*/
|
|
do {
|
|
if (next_mz)
|
|
mz = next_mz;
|
|
else
|
|
mz = mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (!mz)
|
|
break;
|
|
|
|
nr_scanned = 0;
|
|
reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat,
|
|
gfp_mask, &nr_scanned);
|
|
nr_reclaimed += reclaimed;
|
|
*total_scanned += nr_scanned;
|
|
spin_lock_irq(&mctz->lock);
|
|
__mem_cgroup_remove_exceeded(mz, mctz);
|
|
|
|
/*
|
|
* If we failed to reclaim anything from this memory cgroup
|
|
* it is time to move on to the next cgroup
|
|
*/
|
|
next_mz = NULL;
|
|
if (!reclaimed)
|
|
next_mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
|
|
excess = soft_limit_excess(mz->memcg);
|
|
/*
|
|
* One school of thought says that we should not add
|
|
* back the node to the tree if reclaim returns 0.
|
|
* But our reclaim could return 0, simply because due
|
|
* to priority we are exposing a smaller subset of
|
|
* memory to reclaim from. Consider this as a longer
|
|
* term TODO.
|
|
*/
|
|
/* If excess == 0, no tree ops */
|
|
__mem_cgroup_insert_exceeded(mz, mctz, excess);
|
|
spin_unlock_irq(&mctz->lock);
|
|
css_put(&mz->memcg->css);
|
|
loop++;
|
|
/*
|
|
* Could not reclaim anything and there are no more
|
|
* mem cgroups to try or we seem to be looping without
|
|
* reclaiming anything.
|
|
*/
|
|
if (!nr_reclaimed &&
|
|
(next_mz == NULL ||
|
|
loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
|
|
break;
|
|
} while (!nr_reclaimed);
|
|
if (next_mz)
|
|
css_put(&next_mz->memcg->css);
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
/*
|
|
* Reclaims as many pages from the given memcg as possible.
|
|
*
|
|
* Caller is responsible for holding css reference for memcg.
|
|
*/
|
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
|
|
{
|
|
int nr_retries = MAX_RECLAIM_RETRIES;
|
|
|
|
/* we call try-to-free pages for make this cgroup empty */
|
|
lru_add_drain_all();
|
|
|
|
drain_all_stock(memcg);
|
|
|
|
/* try to free all pages in this cgroup */
|
|
while (nr_retries && page_counter_read(&memcg->memory)) {
|
|
int progress;
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
progress = try_to_free_mem_cgroup_pages(memcg, 1,
|
|
GFP_KERNEL, true);
|
|
if (!progress) {
|
|
nr_retries--;
|
|
/* maybe some writeback is necessary */
|
|
congestion_wait(BLK_RW_ASYNC, HZ/10);
|
|
}
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_force_empty_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes,
|
|
loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return -EINVAL;
|
|
return mem_cgroup_force_empty(memcg) ?: nbytes;
|
|
}
|
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
if (val == 1)
|
|
return 0;
|
|
|
|
pr_warn_once("Non-hierarchical mode is deprecated. "
|
|
"Please report your usecase to linux-mm@kvack.org if you "
|
|
"depend on this functionality.\n");
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
unsigned long val;
|
|
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
/* mem_cgroup_threshold() calls here from irqsafe context */
|
|
cgroup_rstat_flush_irqsafe(memcg->css.cgroup);
|
|
val = memcg_page_state(memcg, NR_FILE_PAGES) +
|
|
memcg_page_state(memcg, NR_ANON_MAPPED);
|
|
if (swap)
|
|
val += memcg_page_state(memcg, MEMCG_SWAP);
|
|
} else {
|
|
if (!swap)
|
|
val = page_counter_read(&memcg->memory);
|
|
else
|
|
val = page_counter_read(&memcg->memsw);
|
|
}
|
|
return val;
|
|
}
|
|
|
|
enum {
|
|
RES_USAGE,
|
|
RES_LIMIT,
|
|
RES_MAX_USAGE,
|
|
RES_FAILCNT,
|
|
RES_SOFT_LIMIT,
|
|
};
|
|
|
|
static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct page_counter *counter;
|
|
|
|
switch (MEMFILE_TYPE(cft->private)) {
|
|
case _MEM:
|
|
counter = &memcg->memory;
|
|
break;
|
|
case _MEMSWAP:
|
|
counter = &memcg->memsw;
|
|
break;
|
|
case _KMEM:
|
|
counter = &memcg->kmem;
|
|
break;
|
|
case _TCP:
|
|
counter = &memcg->tcpmem;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
switch (MEMFILE_ATTR(cft->private)) {
|
|
case RES_USAGE:
|
|
if (counter == &memcg->memory)
|
|
return (u64)mem_cgroup_usage(memcg, false) * PAGE_SIZE;
|
|
if (counter == &memcg->memsw)
|
|
return (u64)mem_cgroup_usage(memcg, true) * PAGE_SIZE;
|
|
return (u64)page_counter_read(counter) * PAGE_SIZE;
|
|
case RES_LIMIT:
|
|
return (u64)counter->max * PAGE_SIZE;
|
|
case RES_MAX_USAGE:
|
|
return (u64)counter->watermark * PAGE_SIZE;
|
|
case RES_FAILCNT:
|
|
return counter->failcnt;
|
|
case RES_SOFT_LIMIT:
|
|
return (u64)memcg->soft_limit * PAGE_SIZE;
|
|
default:
|
|
BUG();
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_online_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
struct obj_cgroup *objcg;
|
|
int memcg_id;
|
|
|
|
if (cgroup_memory_nokmem)
|
|
return 0;
|
|
|
|
BUG_ON(memcg->kmemcg_id >= 0);
|
|
BUG_ON(memcg->kmem_state);
|
|
|
|
memcg_id = memcg_alloc_cache_id();
|
|
if (memcg_id < 0)
|
|
return memcg_id;
|
|
|
|
objcg = obj_cgroup_alloc();
|
|
if (!objcg) {
|
|
memcg_free_cache_id(memcg_id);
|
|
return -ENOMEM;
|
|
}
|
|
objcg->memcg = memcg;
|
|
rcu_assign_pointer(memcg->objcg, objcg);
|
|
|
|
static_branch_enable(&memcg_kmem_enabled_key);
|
|
|
|
memcg->kmemcg_id = memcg_id;
|
|
memcg->kmem_state = KMEM_ONLINE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_offline_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
struct mem_cgroup *parent, *child;
|
|
int kmemcg_id;
|
|
|
|
if (memcg->kmem_state != KMEM_ONLINE)
|
|
return;
|
|
|
|
memcg->kmem_state = KMEM_ALLOCATED;
|
|
|
|
parent = parent_mem_cgroup(memcg);
|
|
if (!parent)
|
|
parent = root_mem_cgroup;
|
|
|
|
memcg_reparent_objcgs(memcg, parent);
|
|
|
|
kmemcg_id = memcg->kmemcg_id;
|
|
BUG_ON(kmemcg_id < 0);
|
|
|
|
/*
|
|
* Change kmemcg_id of this cgroup and all its descendants to the
|
|
* parent's id, and then move all entries from this cgroup's list_lrus
|
|
* to ones of the parent. After we have finished, all list_lrus
|
|
* corresponding to this cgroup are guaranteed to remain empty. The
|
|
* ordering is imposed by list_lru_node->lock taken by
|
|
* memcg_drain_all_list_lrus().
|
|
*/
|
|
rcu_read_lock(); /* can be called from css_free w/o cgroup_mutex */
|
|
css_for_each_descendant_pre(css, &memcg->css) {
|
|
child = mem_cgroup_from_css(css);
|
|
BUG_ON(child->kmemcg_id != kmemcg_id);
|
|
child->kmemcg_id = parent->kmemcg_id;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
memcg_drain_all_list_lrus(kmemcg_id, parent);
|
|
|
|
memcg_free_cache_id(kmemcg_id);
|
|
}
|
|
|
|
static void memcg_free_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
/* css_alloc() failed, offlining didn't happen */
|
|
if (unlikely(memcg->kmem_state == KMEM_ONLINE))
|
|
memcg_offline_kmem(memcg);
|
|
}
|
|
#else
|
|
static int memcg_online_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
return 0;
|
|
}
|
|
static void memcg_offline_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
static void memcg_free_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
static int memcg_update_kmem_max(struct mem_cgroup *memcg,
|
|
unsigned long max)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&memcg_max_mutex);
|
|
ret = page_counter_set_max(&memcg->kmem, max);
|
|
mutex_unlock(&memcg_max_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static int memcg_update_tcp_max(struct mem_cgroup *memcg, unsigned long max)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&memcg_max_mutex);
|
|
|
|
ret = page_counter_set_max(&memcg->tcpmem, max);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (!memcg->tcpmem_active) {
|
|
/*
|
|
* The active flag needs to be written after the static_key
|
|
* update. This is what guarantees that the socket activation
|
|
* function is the last one to run. See mem_cgroup_sk_alloc()
|
|
* for details, and note that we don't mark any socket as
|
|
* belonging to this memcg until that flag is up.
|
|
*
|
|
* We need to do this, because static_keys will span multiple
|
|
* sites, but we can't control their order. If we mark a socket
|
|
* as accounted, but the accounting functions are not patched in
|
|
* yet, we'll lose accounting.
|
|
*
|
|
* We never race with the readers in mem_cgroup_sk_alloc(),
|
|
* because when this value change, the code to process it is not
|
|
* patched in yet.
|
|
*/
|
|
static_branch_inc(&memcg_sockets_enabled_key);
|
|
memcg->tcpmem_active = true;
|
|
}
|
|
out:
|
|
mutex_unlock(&memcg_max_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* The user of this function is...
|
|
* RES_LIMIT.
|
|
*/
|
|
static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long nr_pages;
|
|
int ret;
|
|
|
|
buf = strstrip(buf);
|
|
ret = page_counter_memparse(buf, "-1", &nr_pages);
|
|
if (ret)
|
|
return ret;
|
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) {
|
|
case RES_LIMIT:
|
|
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
switch (MEMFILE_TYPE(of_cft(of)->private)) {
|
|
case _MEM:
|
|
ret = mem_cgroup_resize_max(memcg, nr_pages, false);
|
|
break;
|
|
case _MEMSWAP:
|
|
ret = mem_cgroup_resize_max(memcg, nr_pages, true);
|
|
break;
|
|
case _KMEM:
|
|
pr_warn_once("kmem.limit_in_bytes is deprecated and will be removed. "
|
|
"Please report your usecase to linux-mm@kvack.org if you "
|
|
"depend on this functionality.\n");
|
|
ret = memcg_update_kmem_max(memcg, nr_pages);
|
|
break;
|
|
case _TCP:
|
|
ret = memcg_update_tcp_max(memcg, nr_pages);
|
|
break;
|
|
}
|
|
break;
|
|
case RES_SOFT_LIMIT:
|
|
memcg->soft_limit = nr_pages;
|
|
ret = 0;
|
|
break;
|
|
}
|
|
return ret ?: nbytes;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_reset(struct kernfs_open_file *of, char *buf,
|
|
size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
struct page_counter *counter;
|
|
|
|
switch (MEMFILE_TYPE(of_cft(of)->private)) {
|
|
case _MEM:
|
|
counter = &memcg->memory;
|
|
break;
|
|
case _MEMSWAP:
|
|
counter = &memcg->memsw;
|
|
break;
|
|
case _KMEM:
|
|
counter = &memcg->kmem;
|
|
break;
|
|
case _TCP:
|
|
counter = &memcg->tcpmem;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
switch (MEMFILE_ATTR(of_cft(of)->private)) {
|
|
case RES_MAX_USAGE:
|
|
page_counter_reset_watermark(counter);
|
|
break;
|
|
case RES_FAILCNT:
|
|
counter->failcnt = 0;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->move_charge_at_immigrate;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val & ~MOVE_MASK)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* No kind of locking is needed in here, because ->can_attach() will
|
|
* check this value once in the beginning of the process, and then carry
|
|
* on with stale data. This means that changes to this value will only
|
|
* affect task migrations starting after the change.
|
|
*/
|
|
memcg->move_charge_at_immigrate = val;
|
|
return 0;
|
|
}
|
|
#else
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
|
|
#define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
|
|
#define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
|
|
#define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
|
|
|
|
static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
|
|
int nid, unsigned int lru_mask, bool tree)
|
|
{
|
|
struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
|
|
unsigned long nr = 0;
|
|
enum lru_list lru;
|
|
|
|
VM_BUG_ON((unsigned)nid >= nr_node_ids);
|
|
|
|
for_each_lru(lru) {
|
|
if (!(BIT(lru) & lru_mask))
|
|
continue;
|
|
if (tree)
|
|
nr += lruvec_page_state(lruvec, NR_LRU_BASE + lru);
|
|
else
|
|
nr += lruvec_page_state_local(lruvec, NR_LRU_BASE + lru);
|
|
}
|
|
return nr;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
|
|
unsigned int lru_mask,
|
|
bool tree)
|
|
{
|
|
unsigned long nr = 0;
|
|
enum lru_list lru;
|
|
|
|
for_each_lru(lru) {
|
|
if (!(BIT(lru) & lru_mask))
|
|
continue;
|
|
if (tree)
|
|
nr += memcg_page_state(memcg, NR_LRU_BASE + lru);
|
|
else
|
|
nr += memcg_page_state_local(memcg, NR_LRU_BASE + lru);
|
|
}
|
|
return nr;
|
|
}
|
|
|
|
static int memcg_numa_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct numa_stat {
|
|
const char *name;
|
|
unsigned int lru_mask;
|
|
};
|
|
|
|
static const struct numa_stat stats[] = {
|
|
{ "total", LRU_ALL },
|
|
{ "file", LRU_ALL_FILE },
|
|
{ "anon", LRU_ALL_ANON },
|
|
{ "unevictable", BIT(LRU_UNEVICTABLE) },
|
|
};
|
|
const struct numa_stat *stat;
|
|
int nid;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
cgroup_rstat_flush(memcg->css.cgroup);
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
seq_printf(m, "%s=%lu", stat->name,
|
|
mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
|
|
false));
|
|
for_each_node_state(nid, N_MEMORY)
|
|
seq_printf(m, " N%d=%lu", nid,
|
|
mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
stat->lru_mask, false));
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
|
|
|
|
seq_printf(m, "hierarchical_%s=%lu", stat->name,
|
|
mem_cgroup_nr_lru_pages(memcg, stat->lru_mask,
|
|
true));
|
|
for_each_node_state(nid, N_MEMORY)
|
|
seq_printf(m, " N%d=%lu", nid,
|
|
mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
stat->lru_mask, true));
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static const unsigned int memcg1_stats[] = {
|
|
NR_FILE_PAGES,
|
|
NR_ANON_MAPPED,
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
NR_ANON_THPS,
|
|
#endif
|
|
NR_SHMEM,
|
|
NR_FILE_MAPPED,
|
|
NR_FILE_DIRTY,
|
|
NR_WRITEBACK,
|
|
MEMCG_SWAP,
|
|
};
|
|
|
|
static const char *const memcg1_stat_names[] = {
|
|
"cache",
|
|
"rss",
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
"rss_huge",
|
|
#endif
|
|
"shmem",
|
|
"mapped_file",
|
|
"dirty",
|
|
"writeback",
|
|
"swap",
|
|
};
|
|
|
|
/* Universal VM events cgroup1 shows, original sort order */
|
|
static const unsigned int memcg1_events[] = {
|
|
PGPGIN,
|
|
PGPGOUT,
|
|
PGFAULT,
|
|
PGMAJFAULT,
|
|
};
|
|
|
|
static int memcg_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
unsigned long memory, memsw;
|
|
struct mem_cgroup *mi;
|
|
unsigned int i;
|
|
|
|
BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
|
|
|
|
cgroup_rstat_flush(memcg->css.cgroup);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
|
|
unsigned long nr;
|
|
|
|
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
|
|
continue;
|
|
nr = memcg_page_state_local(memcg, memcg1_stats[i]);
|
|
seq_printf(m, "%s %lu\n", memcg1_stat_names[i], nr * PAGE_SIZE);
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
|
|
seq_printf(m, "%s %lu\n", vm_event_name(memcg1_events[i]),
|
|
memcg_events_local(memcg, memcg1_events[i]));
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
seq_printf(m, "%s %lu\n", lru_list_name(i),
|
|
memcg_page_state_local(memcg, NR_LRU_BASE + i) *
|
|
PAGE_SIZE);
|
|
|
|
/* Hierarchical information */
|
|
memory = memsw = PAGE_COUNTER_MAX;
|
|
for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
|
|
memory = min(memory, READ_ONCE(mi->memory.max));
|
|
memsw = min(memsw, READ_ONCE(mi->memsw.max));
|
|
}
|
|
seq_printf(m, "hierarchical_memory_limit %llu\n",
|
|
(u64)memory * PAGE_SIZE);
|
|
if (do_memsw_account())
|
|
seq_printf(m, "hierarchical_memsw_limit %llu\n",
|
|
(u64)memsw * PAGE_SIZE);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
|
|
unsigned long nr;
|
|
|
|
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
|
|
continue;
|
|
nr = memcg_page_state(memcg, memcg1_stats[i]);
|
|
seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
|
|
(u64)nr * PAGE_SIZE);
|
|
}
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
|
|
seq_printf(m, "total_%s %llu\n",
|
|
vm_event_name(memcg1_events[i]),
|
|
(u64)memcg_events(memcg, memcg1_events[i]));
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
seq_printf(m, "total_%s %llu\n", lru_list_name(i),
|
|
(u64)memcg_page_state(memcg, NR_LRU_BASE + i) *
|
|
PAGE_SIZE);
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
{
|
|
pg_data_t *pgdat;
|
|
struct mem_cgroup_per_node *mz;
|
|
unsigned long anon_cost = 0;
|
|
unsigned long file_cost = 0;
|
|
|
|
for_each_online_pgdat(pgdat) {
|
|
mz = memcg->nodeinfo[pgdat->node_id];
|
|
|
|
anon_cost += mz->lruvec.anon_cost;
|
|
file_cost += mz->lruvec.file_cost;
|
|
}
|
|
seq_printf(m, "anon_cost %lu\n", anon_cost);
|
|
seq_printf(m, "file_cost %lu\n", file_cost);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return mem_cgroup_swappiness(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val > 200)
|
|
return -EINVAL;
|
|
|
|
if (!mem_cgroup_is_root(memcg))
|
|
memcg->swappiness = val;
|
|
else
|
|
vm_swappiness = val;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
struct mem_cgroup_threshold_ary *t;
|
|
unsigned long usage;
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
if (!swap)
|
|
t = rcu_dereference(memcg->thresholds.primary);
|
|
else
|
|
t = rcu_dereference(memcg->memsw_thresholds.primary);
|
|
|
|
if (!t)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, swap);
|
|
|
|
/*
|
|
* current_threshold points to threshold just below or equal to usage.
|
|
* If it's not true, a threshold was crossed after last
|
|
* call of __mem_cgroup_threshold().
|
|
*/
|
|
i = t->current_threshold;
|
|
|
|
/*
|
|
* Iterate backward over array of thresholds starting from
|
|
* current_threshold and check if a threshold is crossed.
|
|
* If none of thresholds below usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* i = current_threshold + 1 */
|
|
i++;
|
|
|
|
/*
|
|
* Iterate forward over array of thresholds starting from
|
|
* current_threshold+1 and check if a threshold is crossed.
|
|
* If none of thresholds above usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* Update current_threshold */
|
|
t->current_threshold = i - 1;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void mem_cgroup_threshold(struct mem_cgroup *memcg)
|
|
{
|
|
while (memcg) {
|
|
__mem_cgroup_threshold(memcg, false);
|
|
if (do_memsw_account())
|
|
__mem_cgroup_threshold(memcg, true);
|
|
|
|
memcg = parent_mem_cgroup(memcg);
|
|
}
|
|
}
|
|
|
|
static int compare_thresholds(const void *a, const void *b)
|
|
{
|
|
const struct mem_cgroup_threshold *_a = a;
|
|
const struct mem_cgroup_threshold *_b = b;
|
|
|
|
if (_a->threshold > _b->threshold)
|
|
return 1;
|
|
|
|
if (_a->threshold < _b->threshold)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry(ev, &memcg->oom_notify, list)
|
|
eventfd_signal(ev->eventfd, 1);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
mem_cgroup_oom_notify_cb(iter);
|
|
}
|
|
|
|
static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
unsigned long threshold;
|
|
unsigned long usage;
|
|
int i, size, ret;
|
|
|
|
ret = page_counter_memparse(args, "-1", &threshold);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM) {
|
|
thresholds = &memcg->thresholds;
|
|
usage = mem_cgroup_usage(memcg, false);
|
|
} else if (type == _MEMSWAP) {
|
|
thresholds = &memcg->memsw_thresholds;
|
|
usage = mem_cgroup_usage(memcg, true);
|
|
} else
|
|
BUG();
|
|
|
|
/* Check if a threshold crossed before adding a new one */
|
|
if (thresholds->primary)
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
size = thresholds->primary ? thresholds->primary->size + 1 : 1;
|
|
|
|
/* Allocate memory for new array of thresholds */
|
|
new = kmalloc(struct_size(new, entries, size), GFP_KERNEL);
|
|
if (!new) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
new->size = size;
|
|
|
|
/* Copy thresholds (if any) to new array */
|
|
if (thresholds->primary)
|
|
memcpy(new->entries, thresholds->primary->entries,
|
|
flex_array_size(new, entries, size - 1));
|
|
|
|
/* Add new threshold */
|
|
new->entries[size - 1].eventfd = eventfd;
|
|
new->entries[size - 1].threshold = threshold;
|
|
|
|
/* Sort thresholds. Registering of new threshold isn't time-critical */
|
|
sort(new->entries, size, sizeof(*new->entries),
|
|
compare_thresholds, NULL);
|
|
|
|
/* Find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0; i < size; i++) {
|
|
if (new->entries[i].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used until
|
|
* rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/* Free old spare buffer and save old primary buffer as spare */
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = thresholds->primary;
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
|
|
}
|
|
|
|
static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
|
|
}
|
|
|
|
static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, enum res_type type)
|
|
{
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
unsigned long usage;
|
|
int i, j, size, entries;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM) {
|
|
thresholds = &memcg->thresholds;
|
|
usage = mem_cgroup_usage(memcg, false);
|
|
} else if (type == _MEMSWAP) {
|
|
thresholds = &memcg->memsw_thresholds;
|
|
usage = mem_cgroup_usage(memcg, true);
|
|
} else
|
|
BUG();
|
|
|
|
if (!thresholds->primary)
|
|
goto unlock;
|
|
|
|
/* Check if a threshold crossed before removing */
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
/* Calculate new number of threshold */
|
|
size = entries = 0;
|
|
for (i = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd != eventfd)
|
|
size++;
|
|
else
|
|
entries++;
|
|
}
|
|
|
|
new = thresholds->spare;
|
|
|
|
/* If no items related to eventfd have been cleared, nothing to do */
|
|
if (!entries)
|
|
goto unlock;
|
|
|
|
/* Set thresholds array to NULL if we don't have thresholds */
|
|
if (!size) {
|
|
kfree(new);
|
|
new = NULL;
|
|
goto swap_buffers;
|
|
}
|
|
|
|
new->size = size;
|
|
|
|
/* Copy thresholds and find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0, j = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd == eventfd)
|
|
continue;
|
|
|
|
new->entries[j] = thresholds->primary->entries[i];
|
|
if (new->entries[j].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used
|
|
* until rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
swap_buffers:
|
|
/* Swap primary and spare array */
|
|
thresholds->spare = thresholds->primary;
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
/* If all events are unregistered, free the spare array */
|
|
if (!new) {
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = NULL;
|
|
}
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
}
|
|
|
|
static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
|
|
}
|
|
|
|
static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
|
|
}
|
|
|
|
static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup_eventfd_list *event;
|
|
|
|
event = kmalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
event->eventfd = eventfd;
|
|
list_add(&event->list, &memcg->oom_notify);
|
|
|
|
/* already in OOM ? */
|
|
if (memcg->under_oom)
|
|
eventfd_signal(eventfd, 1);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
|
|
struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev, *tmp;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
|
|
if (ev->eventfd == eventfd) {
|
|
list_del(&ev->list);
|
|
kfree(ev);
|
|
}
|
|
}
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(sf);
|
|
|
|
seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
|
|
seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
|
|
seq_printf(sf, "oom_kill %lu\n",
|
|
atomic_long_read(&memcg->memory_events[MEMCG_OOM_KILL]));
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */
|
|
if (mem_cgroup_is_root(memcg) || !((val == 0) || (val == 1)))
|
|
return -EINVAL;
|
|
|
|
memcg->oom_kill_disable = val;
|
|
if (!val)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_CGROUP_WRITEBACK
|
|
|
|
#include <trace/events/writeback.h>
|
|
|
|
static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
|
|
{
|
|
return wb_domain_init(&memcg->cgwb_domain, gfp);
|
|
}
|
|
|
|
static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
|
|
{
|
|
wb_domain_exit(&memcg->cgwb_domain);
|
|
}
|
|
|
|
static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
|
|
{
|
|
wb_domain_size_changed(&memcg->cgwb_domain);
|
|
}
|
|
|
|
struct wb_domain *mem_cgroup_wb_domain(struct bdi_writeback *wb)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
|
|
|
|
if (!memcg->css.parent)
|
|
return NULL;
|
|
|
|
return &memcg->cgwb_domain;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_wb_stats - retrieve writeback related stats from its memcg
|
|
* @wb: bdi_writeback in question
|
|
* @pfilepages: out parameter for number of file pages
|
|
* @pheadroom: out parameter for number of allocatable pages according to memcg
|
|
* @pdirty: out parameter for number of dirty pages
|
|
* @pwriteback: out parameter for number of pages under writeback
|
|
*
|
|
* Determine the numbers of file, headroom, dirty, and writeback pages in
|
|
* @wb's memcg. File, dirty and writeback are self-explanatory. Headroom
|
|
* is a bit more involved.
|
|
*
|
|
* A memcg's headroom is "min(max, high) - used". In the hierarchy, the
|
|
* headroom is calculated as the lowest headroom of itself and the
|
|
* ancestors. Note that this doesn't consider the actual amount of
|
|
* available memory in the system. The caller should further cap
|
|
* *@pheadroom accordingly.
|
|
*/
|
|
void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
|
|
unsigned long *pheadroom, unsigned long *pdirty,
|
|
unsigned long *pwriteback)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
|
|
struct mem_cgroup *parent;
|
|
|
|
cgroup_rstat_flush_irqsafe(memcg->css.cgroup);
|
|
|
|
*pdirty = memcg_page_state(memcg, NR_FILE_DIRTY);
|
|
*pwriteback = memcg_page_state(memcg, NR_WRITEBACK);
|
|
*pfilepages = memcg_page_state(memcg, NR_INACTIVE_FILE) +
|
|
memcg_page_state(memcg, NR_ACTIVE_FILE);
|
|
|
|
*pheadroom = PAGE_COUNTER_MAX;
|
|
while ((parent = parent_mem_cgroup(memcg))) {
|
|
unsigned long ceiling = min(READ_ONCE(memcg->memory.max),
|
|
READ_ONCE(memcg->memory.high));
|
|
unsigned long used = page_counter_read(&memcg->memory);
|
|
|
|
*pheadroom = min(*pheadroom, ceiling - min(ceiling, used));
|
|
memcg = parent;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Foreign dirty flushing
|
|
*
|
|
* There's an inherent mismatch between memcg and writeback. The former
|
|
* tracks ownership per-page while the latter per-inode. This was a
|
|
* deliberate design decision because honoring per-page ownership in the
|
|
* writeback path is complicated, may lead to higher CPU and IO overheads
|
|
* and deemed unnecessary given that write-sharing an inode across
|
|
* different cgroups isn't a common use-case.
|
|
*
|
|
* Combined with inode majority-writer ownership switching, this works well
|
|
* enough in most cases but there are some pathological cases. For
|
|
* example, let's say there are two cgroups A and B which keep writing to
|
|
* different but confined parts of the same inode. B owns the inode and
|
|
* A's memory is limited far below B's. A's dirty ratio can rise enough to
|
|
* trigger balance_dirty_pages() sleeps but B's can be low enough to avoid
|
|
* triggering background writeback. A will be slowed down without a way to
|
|
* make writeback of the dirty pages happen.
|
|
*
|
|
* Conditions like the above can lead to a cgroup getting repeatedly and
|
|
* severely throttled after making some progress after each
|
|
* dirty_expire_interval while the underlying IO device is almost
|
|
* completely idle.
|
|
*
|
|
* Solving this problem completely requires matching the ownership tracking
|
|
* granularities between memcg and writeback in either direction. However,
|
|
* the more egregious behaviors can be avoided by simply remembering the
|
|
* most recent foreign dirtying events and initiating remote flushes on
|
|
* them when local writeback isn't enough to keep the memory clean enough.
|
|
*
|
|
* The following two functions implement such mechanism. When a foreign
|
|
* page - a page whose memcg and writeback ownerships don't match - is
|
|
* dirtied, mem_cgroup_track_foreign_dirty() records the inode owning
|
|
* bdi_writeback on the page owning memcg. When balance_dirty_pages()
|
|
* decides that the memcg needs to sleep due to high dirty ratio, it calls
|
|
* mem_cgroup_flush_foreign() which queues writeback on the recorded
|
|
* foreign bdi_writebacks which haven't expired. Both the numbers of
|
|
* recorded bdi_writebacks and concurrent in-flight foreign writebacks are
|
|
* limited to MEMCG_CGWB_FRN_CNT.
|
|
*
|
|
* The mechanism only remembers IDs and doesn't hold any object references.
|
|
* As being wrong occasionally doesn't matter, updates and accesses to the
|
|
* records are lockless and racy.
|
|
*/
|
|
void mem_cgroup_track_foreign_dirty_slowpath(struct page *page,
|
|
struct bdi_writeback *wb)
|
|
{
|
|
struct mem_cgroup *memcg = page_memcg(page);
|
|
struct memcg_cgwb_frn *frn;
|
|
u64 now = get_jiffies_64();
|
|
u64 oldest_at = now;
|
|
int oldest = -1;
|
|
int i;
|
|
|
|
trace_track_foreign_dirty(page, wb);
|
|
|
|
/*
|
|
* Pick the slot to use. If there is already a slot for @wb, keep
|
|
* using it. If not replace the oldest one which isn't being
|
|
* written out.
|
|
*/
|
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) {
|
|
frn = &memcg->cgwb_frn[i];
|
|
if (frn->bdi_id == wb->bdi->id &&
|
|
frn->memcg_id == wb->memcg_css->id)
|
|
break;
|
|
if (time_before64(frn->at, oldest_at) &&
|
|
atomic_read(&frn->done.cnt) == 1) {
|
|
oldest = i;
|
|
oldest_at = frn->at;
|
|
}
|
|
}
|
|
|
|
if (i < MEMCG_CGWB_FRN_CNT) {
|
|
/*
|
|
* Re-using an existing one. Update timestamp lazily to
|
|
* avoid making the cacheline hot. We want them to be
|
|
* reasonably up-to-date and significantly shorter than
|
|
* dirty_expire_interval as that's what expires the record.
|
|
* Use the shorter of 1s and dirty_expire_interval / 8.
|
|
*/
|
|
unsigned long update_intv =
|
|
min_t(unsigned long, HZ,
|
|
msecs_to_jiffies(dirty_expire_interval * 10) / 8);
|
|
|
|
if (time_before64(frn->at, now - update_intv))
|
|
frn->at = now;
|
|
} else if (oldest >= 0) {
|
|
/* replace the oldest free one */
|
|
frn = &memcg->cgwb_frn[oldest];
|
|
frn->bdi_id = wb->bdi->id;
|
|
frn->memcg_id = wb->memcg_css->id;
|
|
frn->at = now;
|
|
}
|
|
}
|
|
|
|
/* issue foreign writeback flushes for recorded foreign dirtying events */
|
|
void mem_cgroup_flush_foreign(struct bdi_writeback *wb)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
|
|
unsigned long intv = msecs_to_jiffies(dirty_expire_interval * 10);
|
|
u64 now = jiffies_64;
|
|
int i;
|
|
|
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++) {
|
|
struct memcg_cgwb_frn *frn = &memcg->cgwb_frn[i];
|
|
|
|
/*
|
|
* If the record is older than dirty_expire_interval,
|
|
* writeback on it has already started. No need to kick it
|
|
* off again. Also, don't start a new one if there's
|
|
* already one in flight.
|
|
*/
|
|
if (time_after64(frn->at, now - intv) &&
|
|
atomic_read(&frn->done.cnt) == 1) {
|
|
frn->at = 0;
|
|
trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id);
|
|
cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id,
|
|
WB_REASON_FOREIGN_FLUSH,
|
|
&frn->done);
|
|
}
|
|
}
|
|
}
|
|
|
|
#else /* CONFIG_CGROUP_WRITEBACK */
|
|
|
|
static int memcg_wb_domain_init(struct mem_cgroup *memcg, gfp_t gfp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_wb_domain_exit(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
|
|
static void memcg_wb_domain_size_changed(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_CGROUP_WRITEBACK */
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* "cgroup.event_control" implementation.
|
|
*
|
|
* This is way over-engineered. It tries to support fully configurable
|
|
* events for each user. Such level of flexibility is completely
|
|
* unnecessary especially in the light of the planned unified hierarchy.
|
|
*
|
|
* Please deprecate this and replace with something simpler if at all
|
|
* possible.
|
|
*/
|
|
|
|
/*
|
|
* Unregister event and free resources.
|
|
*
|
|
* Gets called from workqueue.
|
|
*/
|
|
static void memcg_event_remove(struct work_struct *work)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(work, struct mem_cgroup_event, remove);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
|
|
remove_wait_queue(event->wqh, &event->wait);
|
|
|
|
event->unregister_event(memcg, event->eventfd);
|
|
|
|
/* Notify userspace the event is going away. */
|
|
eventfd_signal(event->eventfd, 1);
|
|
|
|
eventfd_ctx_put(event->eventfd);
|
|
kfree(event);
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/*
|
|
* Gets called on EPOLLHUP on eventfd when user closes it.
|
|
*
|
|
* Called with wqh->lock held and interrupts disabled.
|
|
*/
|
|
static int memcg_event_wake(wait_queue_entry_t *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(wait, struct mem_cgroup_event, wait);
|
|
struct mem_cgroup *memcg = event->memcg;
|
|
__poll_t flags = key_to_poll(key);
|
|
|
|
if (flags & EPOLLHUP) {
|
|
/*
|
|
* If the event has been detached at cgroup removal, we
|
|
* can simply return knowing the other side will cleanup
|
|
* for us.
|
|
*
|
|
* We can't race against event freeing since the other
|
|
* side will require wqh->lock via remove_wait_queue(),
|
|
* which we hold.
|
|
*/
|
|
spin_lock(&memcg->event_list_lock);
|
|
if (!list_empty(&event->list)) {
|
|
list_del_init(&event->list);
|
|
/*
|
|
* We are in atomic context, but cgroup_event_remove()
|
|
* may sleep, so we have to call it in workqueue.
|
|
*/
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&memcg->event_list_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_event_ptable_queue_proc(struct file *file,
|
|
wait_queue_head_t *wqh, poll_table *pt)
|
|
{
|
|
struct mem_cgroup_event *event =
|
|
container_of(pt, struct mem_cgroup_event, pt);
|
|
|
|
event->wqh = wqh;
|
|
add_wait_queue(wqh, &event->wait);
|
|
}
|
|
|
|
/*
|
|
* DO NOT USE IN NEW FILES.
|
|
*
|
|
* Parse input and register new cgroup event handler.
|
|
*
|
|
* Input must be in format '<event_fd> <control_fd> <args>'.
|
|
* Interpretation of args is defined by control file implementation.
|
|
*/
|
|
static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct cgroup_subsys_state *css = of_css(of);
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event;
|
|
struct cgroup_subsys_state *cfile_css;
|
|
unsigned int efd, cfd;
|
|
struct fd efile;
|
|
struct fd cfile;
|
|
const char *name;
|
|
char *endp;
|
|
int ret;
|
|
|
|
buf = strstrip(buf);
|
|
|
|
efd = simple_strtoul(buf, &endp, 10);
|
|
if (*endp != ' ')
|
|
return -EINVAL;
|
|
buf = endp + 1;
|
|
|
|
cfd = simple_strtoul(buf, &endp, 10);
|
|
if ((*endp != ' ') && (*endp != '\0'))
|
|
return -EINVAL;
|
|
buf = endp + 1;
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
event->memcg = memcg;
|
|
INIT_LIST_HEAD(&event->list);
|
|
init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
|
|
init_waitqueue_func_entry(&event->wait, memcg_event_wake);
|
|
INIT_WORK(&event->remove, memcg_event_remove);
|
|
|
|
efile = fdget(efd);
|
|
if (!efile.file) {
|
|
ret = -EBADF;
|
|
goto out_kfree;
|
|
}
|
|
|
|
event->eventfd = eventfd_ctx_fileget(efile.file);
|
|
if (IS_ERR(event->eventfd)) {
|
|
ret = PTR_ERR(event->eventfd);
|
|
goto out_put_efile;
|
|
}
|
|
|
|
cfile = fdget(cfd);
|
|
if (!cfile.file) {
|
|
ret = -EBADF;
|
|
goto out_put_eventfd;
|
|
}
|
|
|
|
/* the process need read permission on control file */
|
|
/* AV: shouldn't we check that it's been opened for read instead? */
|
|
ret = file_permission(cfile.file, MAY_READ);
|
|
if (ret < 0)
|
|
goto out_put_cfile;
|
|
|
|
/*
|
|
* Determine the event callbacks and set them in @event. This used
|
|
* to be done via struct cftype but cgroup core no longer knows
|
|
* about these events. The following is crude but the whole thing
|
|
* is for compatibility anyway.
|
|
*
|
|
* DO NOT ADD NEW FILES.
|
|
*/
|
|
name = cfile.file->f_path.dentry->d_name.name;
|
|
|
|
if (!strcmp(name, "memory.usage_in_bytes")) {
|
|
event->register_event = mem_cgroup_usage_register_event;
|
|
event->unregister_event = mem_cgroup_usage_unregister_event;
|
|
} else if (!strcmp(name, "memory.oom_control")) {
|
|
event->register_event = mem_cgroup_oom_register_event;
|
|
event->unregister_event = mem_cgroup_oom_unregister_event;
|
|
} else if (!strcmp(name, "memory.pressure_level")) {
|
|
event->register_event = vmpressure_register_event;
|
|
event->unregister_event = vmpressure_unregister_event;
|
|
} else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
|
|
event->register_event = memsw_cgroup_usage_register_event;
|
|
event->unregister_event = memsw_cgroup_usage_unregister_event;
|
|
} else {
|
|
ret = -EINVAL;
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
/*
|
|
* Verify @cfile should belong to @css. Also, remaining events are
|
|
* automatically removed on cgroup destruction but the removal is
|
|
* asynchronous, so take an extra ref on @css.
|
|
*/
|
|
cfile_css = css_tryget_online_from_dir(cfile.file->f_path.dentry->d_parent,
|
|
&memory_cgrp_subsys);
|
|
ret = -EINVAL;
|
|
if (IS_ERR(cfile_css))
|
|
goto out_put_cfile;
|
|
if (cfile_css != css) {
|
|
css_put(cfile_css);
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
ret = event->register_event(memcg, event->eventfd, buf);
|
|
if (ret)
|
|
goto out_put_css;
|
|
|
|
vfs_poll(efile.file, &event->pt);
|
|
|
|
spin_lock_irq(&memcg->event_list_lock);
|
|
list_add(&event->list, &memcg->event_list);
|
|
spin_unlock_irq(&memcg->event_list_lock);
|
|
|
|
fdput(cfile);
|
|
fdput(efile);
|
|
|
|
return nbytes;
|
|
|
|
out_put_css:
|
|
css_put(css);
|
|
out_put_cfile:
|
|
fdput(cfile);
|
|
out_put_eventfd:
|
|
eventfd_ctx_put(event->eventfd);
|
|
out_put_efile:
|
|
fdput(efile);
|
|
out_kfree:
|
|
kfree(event);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct cftype mem_cgroup_legacy_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "soft_limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.seq_show = memcg_stat_show,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.write = mem_cgroup_force_empty_write,
|
|
},
|
|
{
|
|
.name = "use_hierarchy",
|
|
.write_u64 = mem_cgroup_hierarchy_write,
|
|
.read_u64 = mem_cgroup_hierarchy_read,
|
|
},
|
|
{
|
|
.name = "cgroup.event_control", /* XXX: for compat */
|
|
.write = memcg_write_event_control,
|
|
.flags = CFTYPE_NO_PREFIX | CFTYPE_WORLD_WRITABLE,
|
|
},
|
|
{
|
|
.name = "swappiness",
|
|
.read_u64 = mem_cgroup_swappiness_read,
|
|
.write_u64 = mem_cgroup_swappiness_write,
|
|
},
|
|
{
|
|
.name = "move_charge_at_immigrate",
|
|
.read_u64 = mem_cgroup_move_charge_read,
|
|
.write_u64 = mem_cgroup_move_charge_write,
|
|
},
|
|
{
|
|
.name = "oom_control",
|
|
.seq_show = mem_cgroup_oom_control_read,
|
|
.write_u64 = mem_cgroup_oom_control_write,
|
|
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
|
|
},
|
|
{
|
|
.name = "pressure_level",
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.seq_show = memcg_numa_stat_show,
|
|
},
|
|
#endif
|
|
{
|
|
.name = "kmem.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.failcnt",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
#if defined(CONFIG_MEMCG_KMEM) && \
|
|
(defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG))
|
|
{
|
|
.name = "kmem.slabinfo",
|
|
.seq_show = memcg_slab_show,
|
|
},
|
|
#endif
|
|
{
|
|
.name = "kmem.tcp.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_TCP, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.tcp.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_TCP, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.tcp.failcnt",
|
|
.private = MEMFILE_PRIVATE(_TCP, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "kmem.tcp.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_TCP, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{ }, /* terminate */
|
|
};
|
|
|
|
/*
|
|
* Private memory cgroup IDR
|
|
*
|
|
* Swap-out records and page cache shadow entries need to store memcg
|
|
* references in constrained space, so we maintain an ID space that is
|
|
* limited to 16 bit (MEM_CGROUP_ID_MAX), limiting the total number of
|
|
* memory-controlled cgroups to 64k.
|
|
*
|
|
* However, there usually are many references to the offline CSS after
|
|
* the cgroup has been destroyed, such as page cache or reclaimable
|
|
* slab objects, that don't need to hang on to the ID. We want to keep
|
|
* those dead CSS from occupying IDs, or we might quickly exhaust the
|
|
* relatively small ID space and prevent the creation of new cgroups
|
|
* even when there are much fewer than 64k cgroups - possibly none.
|
|
*
|
|
* Maintain a private 16-bit ID space for memcg, and allow the ID to
|
|
* be freed and recycled when it's no longer needed, which is usually
|
|
* when the CSS is offlined.
|
|
*
|
|
* The only exception to that are records of swapped out tmpfs/shmem
|
|
* pages that need to be attributed to live ancestors on swapin. But
|
|
* those references are manageable from userspace.
|
|
*/
|
|
|
|
static DEFINE_IDR(mem_cgroup_idr);
|
|
|
|
static void mem_cgroup_id_remove(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg->id.id > 0) {
|
|
idr_remove(&mem_cgroup_idr, memcg->id.id);
|
|
memcg->id.id = 0;
|
|
}
|
|
}
|
|
|
|
static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
|
|
unsigned int n)
|
|
{
|
|
refcount_add(n, &memcg->id.ref);
|
|
}
|
|
|
|
static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
|
|
{
|
|
if (refcount_sub_and_test(n, &memcg->id.ref)) {
|
|
mem_cgroup_id_remove(memcg);
|
|
|
|
/* Memcg ID pins CSS */
|
|
css_put(&memcg->css);
|
|
}
|
|
}
|
|
|
|
static inline void mem_cgroup_id_put(struct mem_cgroup *memcg)
|
|
{
|
|
mem_cgroup_id_put_many(memcg, 1);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_from_id - look up a memcg from a memcg id
|
|
* @id: the memcg id to look up
|
|
*
|
|
* Caller must hold rcu_read_lock().
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
|
|
{
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
return idr_find(&mem_cgroup_idr, id);
|
|
}
|
|
|
|
static int alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
int tmp = node;
|
|
/*
|
|
* This routine is called against possible nodes.
|
|
* But it's BUG to call kmalloc() against offline node.
|
|
*
|
|
* TODO: this routine can waste much memory for nodes which will
|
|
* never be onlined. It's better to use memory hotplug callback
|
|
* function.
|
|
*/
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
|
|
if (!pn)
|
|
return 1;
|
|
|
|
pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu,
|
|
GFP_KERNEL_ACCOUNT);
|
|
if (!pn->lruvec_stats_percpu) {
|
|
kfree(pn);
|
|
return 1;
|
|
}
|
|
|
|
lruvec_init(&pn->lruvec);
|
|
pn->usage_in_excess = 0;
|
|
pn->on_tree = false;
|
|
pn->memcg = memcg;
|
|
|
|
memcg->nodeinfo[node] = pn;
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn = memcg->nodeinfo[node];
|
|
|
|
if (!pn)
|
|
return;
|
|
|
|
free_percpu(pn->lruvec_stats_percpu);
|
|
kfree(pn);
|
|
}
|
|
|
|
static void __mem_cgroup_free(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
for_each_node(node)
|
|
free_mem_cgroup_per_node_info(memcg, node);
|
|
free_percpu(memcg->vmstats_percpu);
|
|
kfree(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_free(struct mem_cgroup *memcg)
|
|
{
|
|
memcg_wb_domain_exit(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
}
|
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned int size;
|
|
int node;
|
|
int __maybe_unused i;
|
|
long error = -ENOMEM;
|
|
|
|
size = sizeof(struct mem_cgroup);
|
|
size += nr_node_ids * sizeof(struct mem_cgroup_per_node *);
|
|
|
|
memcg = kzalloc(size, GFP_KERNEL);
|
|
if (!memcg)
|
|
return ERR_PTR(error);
|
|
|
|
memcg->id.id = idr_alloc(&mem_cgroup_idr, NULL,
|
|
1, MEM_CGROUP_ID_MAX,
|
|
GFP_KERNEL);
|
|
if (memcg->id.id < 0) {
|
|
error = memcg->id.id;
|
|
goto fail;
|
|
}
|
|
|
|
memcg->vmstats_percpu = alloc_percpu_gfp(struct memcg_vmstats_percpu,
|
|
GFP_KERNEL_ACCOUNT);
|
|
if (!memcg->vmstats_percpu)
|
|
goto fail;
|
|
|
|
for_each_node(node)
|
|
if (alloc_mem_cgroup_per_node_info(memcg, node))
|
|
goto fail;
|
|
|
|
if (memcg_wb_domain_init(memcg, GFP_KERNEL))
|
|
goto fail;
|
|
|
|
INIT_WORK(&memcg->high_work, high_work_func);
|
|
INIT_LIST_HEAD(&memcg->oom_notify);
|
|
mutex_init(&memcg->thresholds_lock);
|
|
spin_lock_init(&memcg->move_lock);
|
|
vmpressure_init(&memcg->vmpressure);
|
|
INIT_LIST_HEAD(&memcg->event_list);
|
|
spin_lock_init(&memcg->event_list_lock);
|
|
memcg->socket_pressure = jiffies;
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
memcg->kmemcg_id = -1;
|
|
INIT_LIST_HEAD(&memcg->objcg_list);
|
|
#endif
|
|
#ifdef CONFIG_CGROUP_WRITEBACK
|
|
INIT_LIST_HEAD(&memcg->cgwb_list);
|
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++)
|
|
memcg->cgwb_frn[i].done =
|
|
__WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq);
|
|
#endif
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
spin_lock_init(&memcg->deferred_split_queue.split_queue_lock);
|
|
INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue);
|
|
memcg->deferred_split_queue.split_queue_len = 0;
|
|
#endif
|
|
idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
|
|
return memcg;
|
|
fail:
|
|
mem_cgroup_id_remove(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static struct cgroup_subsys_state * __ref
|
|
mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(parent_css);
|
|
struct mem_cgroup *memcg, *old_memcg;
|
|
long error = -ENOMEM;
|
|
|
|
old_memcg = set_active_memcg(parent);
|
|
memcg = mem_cgroup_alloc();
|
|
set_active_memcg(old_memcg);
|
|
if (IS_ERR(memcg))
|
|
return ERR_CAST(memcg);
|
|
|
|
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
|
|
memcg->soft_limit = PAGE_COUNTER_MAX;
|
|
page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX);
|
|
if (parent) {
|
|
memcg->swappiness = mem_cgroup_swappiness(parent);
|
|
memcg->oom_kill_disable = parent->oom_kill_disable;
|
|
|
|
page_counter_init(&memcg->memory, &parent->memory);
|
|
page_counter_init(&memcg->swap, &parent->swap);
|
|
page_counter_init(&memcg->kmem, &parent->kmem);
|
|
page_counter_init(&memcg->tcpmem, &parent->tcpmem);
|
|
} else {
|
|
page_counter_init(&memcg->memory, NULL);
|
|
page_counter_init(&memcg->swap, NULL);
|
|
page_counter_init(&memcg->kmem, NULL);
|
|
page_counter_init(&memcg->tcpmem, NULL);
|
|
|
|
root_mem_cgroup = memcg;
|
|
return &memcg->css;
|
|
}
|
|
|
|
/* The following stuff does not apply to the root */
|
|
error = memcg_online_kmem(memcg);
|
|
if (error)
|
|
goto fail;
|
|
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
|
|
static_branch_inc(&memcg_sockets_enabled_key);
|
|
|
|
return &memcg->css;
|
|
fail:
|
|
mem_cgroup_id_remove(memcg);
|
|
mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
/*
|
|
* A memcg must be visible for expand_shrinker_info()
|
|
* by the time the maps are allocated. So, we allocate maps
|
|
* here, when for_each_mem_cgroup() can't skip it.
|
|
*/
|
|
if (alloc_shrinker_info(memcg)) {
|
|
mem_cgroup_id_remove(memcg);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Online state pins memcg ID, memcg ID pins CSS */
|
|
refcount_set(&memcg->id.ref, 1);
|
|
css_get(css);
|
|
|
|
if (unlikely(mem_cgroup_is_root(memcg)))
|
|
queue_delayed_work(system_unbound_wq, &stats_flush_dwork,
|
|
2UL*HZ);
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_event *event, *tmp;
|
|
|
|
/*
|
|
* Unregister events and notify userspace.
|
|
* Notify userspace about cgroup removing only after rmdir of cgroup
|
|
* directory to avoid race between userspace and kernelspace.
|
|
*/
|
|
spin_lock_irq(&memcg->event_list_lock);
|
|
list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
|
|
list_del_init(&event->list);
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock_irq(&memcg->event_list_lock);
|
|
|
|
page_counter_set_min(&memcg->memory, 0);
|
|
page_counter_set_low(&memcg->memory, 0);
|
|
|
|
memcg_offline_kmem(memcg);
|
|
reparent_shrinker_deferred(memcg);
|
|
wb_memcg_offline(memcg);
|
|
|
|
drain_all_stock(memcg);
|
|
|
|
mem_cgroup_id_put(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_css_released(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
invalidate_reclaim_iterators(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
int __maybe_unused i;
|
|
|
|
#ifdef CONFIG_CGROUP_WRITEBACK
|
|
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++)
|
|
wb_wait_for_completion(&memcg->cgwb_frn[i].done);
|
|
#endif
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
|
|
static_branch_dec(&memcg_sockets_enabled_key);
|
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active)
|
|
static_branch_dec(&memcg_sockets_enabled_key);
|
|
|
|
vmpressure_cleanup(&memcg->vmpressure);
|
|
cancel_work_sync(&memcg->high_work);
|
|
mem_cgroup_remove_from_trees(memcg);
|
|
free_shrinker_info(memcg);
|
|
memcg_free_kmem(memcg);
|
|
mem_cgroup_free(memcg);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_css_reset - reset the states of a mem_cgroup
|
|
* @css: the target css
|
|
*
|
|
* Reset the states of the mem_cgroup associated with @css. This is
|
|
* invoked when the userland requests disabling on the default hierarchy
|
|
* but the memcg is pinned through dependency. The memcg should stop
|
|
* applying policies and should revert to the vanilla state as it may be
|
|
* made visible again.
|
|
*
|
|
* The current implementation only resets the essential configurations.
|
|
* This needs to be expanded to cover all the visible parts.
|
|
*/
|
|
static void mem_cgroup_css_reset(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
page_counter_set_max(&memcg->memory, PAGE_COUNTER_MAX);
|
|
page_counter_set_max(&memcg->swap, PAGE_COUNTER_MAX);
|
|
page_counter_set_max(&memcg->kmem, PAGE_COUNTER_MAX);
|
|
page_counter_set_max(&memcg->tcpmem, PAGE_COUNTER_MAX);
|
|
page_counter_set_min(&memcg->memory, 0);
|
|
page_counter_set_low(&memcg->memory, 0);
|
|
page_counter_set_high(&memcg->memory, PAGE_COUNTER_MAX);
|
|
memcg->soft_limit = PAGE_COUNTER_MAX;
|
|
page_counter_set_high(&memcg->swap, PAGE_COUNTER_MAX);
|
|
memcg_wb_domain_size_changed(memcg);
|
|
}
|
|
|
|
void mem_cgroup_flush_stats(void)
|
|
{
|
|
if (!spin_trylock(&stats_flush_lock))
|
|
return;
|
|
|
|
cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup);
|
|
spin_unlock(&stats_flush_lock);
|
|
}
|
|
|
|
static void flush_memcg_stats_dwork(struct work_struct *w)
|
|
{
|
|
mem_cgroup_flush_stats();
|
|
queue_delayed_work(system_unbound_wq, &stats_flush_dwork, 2UL*HZ);
|
|
}
|
|
|
|
static void flush_memcg_stats_work(struct work_struct *w)
|
|
{
|
|
mem_cgroup_flush_stats();
|
|
}
|
|
|
|
static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
|
|
struct memcg_vmstats_percpu *statc;
|
|
long delta, v;
|
|
int i, nid;
|
|
|
|
statc = per_cpu_ptr(memcg->vmstats_percpu, cpu);
|
|
|
|
for (i = 0; i < MEMCG_NR_STAT; i++) {
|
|
/*
|
|
* Collect the aggregated propagation counts of groups
|
|
* below us. We're in a per-cpu loop here and this is
|
|
* a global counter, so the first cycle will get them.
|
|
*/
|
|
delta = memcg->vmstats.state_pending[i];
|
|
if (delta)
|
|
memcg->vmstats.state_pending[i] = 0;
|
|
|
|
/* Add CPU changes on this level since the last flush */
|
|
v = READ_ONCE(statc->state[i]);
|
|
if (v != statc->state_prev[i]) {
|
|
delta += v - statc->state_prev[i];
|
|
statc->state_prev[i] = v;
|
|
}
|
|
|
|
if (!delta)
|
|
continue;
|
|
|
|
/* Aggregate counts on this level and propagate upwards */
|
|
memcg->vmstats.state[i] += delta;
|
|
if (parent)
|
|
parent->vmstats.state_pending[i] += delta;
|
|
}
|
|
|
|
for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
|
|
delta = memcg->vmstats.events_pending[i];
|
|
if (delta)
|
|
memcg->vmstats.events_pending[i] = 0;
|
|
|
|
v = READ_ONCE(statc->events[i]);
|
|
if (v != statc->events_prev[i]) {
|
|
delta += v - statc->events_prev[i];
|
|
statc->events_prev[i] = v;
|
|
}
|
|
|
|
if (!delta)
|
|
continue;
|
|
|
|
memcg->vmstats.events[i] += delta;
|
|
if (parent)
|
|
parent->vmstats.events_pending[i] += delta;
|
|
}
|
|
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid];
|
|
struct mem_cgroup_per_node *ppn = NULL;
|
|
struct lruvec_stats_percpu *lstatc;
|
|
|
|
if (parent)
|
|
ppn = parent->nodeinfo[nid];
|
|
|
|
lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu);
|
|
|
|
for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
|
|
delta = pn->lruvec_stats.state_pending[i];
|
|
if (delta)
|
|
pn->lruvec_stats.state_pending[i] = 0;
|
|
|
|
v = READ_ONCE(lstatc->state[i]);
|
|
if (v != lstatc->state_prev[i]) {
|
|
delta += v - lstatc->state_prev[i];
|
|
lstatc->state_prev[i] = v;
|
|
}
|
|
|
|
if (!delta)
|
|
continue;
|
|
|
|
pn->lruvec_stats.state[i] += delta;
|
|
if (ppn)
|
|
ppn->lruvec_stats.state_pending[i] += delta;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
/* Handlers for move charge at task migration. */
|
|
static int mem_cgroup_do_precharge(unsigned long count)
|
|
{
|
|
int ret;
|
|
|
|
/* Try a single bulk charge without reclaim first, kswapd may wake */
|
|
ret = try_charge(mc.to, GFP_KERNEL & ~__GFP_DIRECT_RECLAIM, count);
|
|
if (!ret) {
|
|
mc.precharge += count;
|
|
return ret;
|
|
}
|
|
|
|
/* Try charges one by one with reclaim, but do not retry */
|
|
while (count--) {
|
|
ret = try_charge(mc.to, GFP_KERNEL | __GFP_NORETRY, 1);
|
|
if (ret)
|
|
return ret;
|
|
mc.precharge++;
|
|
cond_resched();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
union mc_target {
|
|
struct page *page;
|
|
swp_entry_t ent;
|
|
};
|
|
|
|
enum mc_target_type {
|
|
MC_TARGET_NONE = 0,
|
|
MC_TARGET_PAGE,
|
|
MC_TARGET_SWAP,
|
|
MC_TARGET_DEVICE,
|
|
};
|
|
|
|
static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent)
|
|
{
|
|
struct page *page = vm_normal_page(vma, addr, ptent);
|
|
|
|
if (!page || !page_mapped(page))
|
|
return NULL;
|
|
if (PageAnon(page)) {
|
|
if (!(mc.flags & MOVE_ANON))
|
|
return NULL;
|
|
} else {
|
|
if (!(mc.flags & MOVE_FILE))
|
|
return NULL;
|
|
}
|
|
if (!get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
#if defined(CONFIG_SWAP) || defined(CONFIG_DEVICE_PRIVATE)
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
swp_entry_t ent = pte_to_swp_entry(ptent);
|
|
|
|
if (!(mc.flags & MOVE_ANON))
|
|
return NULL;
|
|
|
|
/*
|
|
* Handle MEMORY_DEVICE_PRIVATE which are ZONE_DEVICE page belonging to
|
|
* a device and because they are not accessible by CPU they are store
|
|
* as special swap entry in the CPU page table.
|
|
*/
|
|
if (is_device_private_entry(ent)) {
|
|
page = pfn_swap_entry_to_page(ent);
|
|
/*
|
|
* MEMORY_DEVICE_PRIVATE means ZONE_DEVICE page and which have
|
|
* a refcount of 1 when free (unlike normal page)
|
|
*/
|
|
if (!page_ref_add_unless(page, 1, 1))
|
|
return NULL;
|
|
return page;
|
|
}
|
|
|
|
if (non_swap_entry(ent))
|
|
return NULL;
|
|
|
|
/*
|
|
* Because lookup_swap_cache() updates some statistics counter,
|
|
* we call find_get_page() with swapper_space directly.
|
|
*/
|
|
page = find_get_page(swap_address_space(ent), swp_offset(ent));
|
|
entry->val = ent.val;
|
|
|
|
return page;
|
|
}
|
|
#else
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
if (!vma->vm_file) /* anonymous vma */
|
|
return NULL;
|
|
if (!(mc.flags & MOVE_FILE))
|
|
return NULL;
|
|
|
|
/* page is moved even if it's not RSS of this task(page-faulted). */
|
|
/* shmem/tmpfs may report page out on swap: account for that too. */
|
|
return find_get_incore_page(vma->vm_file->f_mapping,
|
|
linear_page_index(vma, addr));
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_account - move account of the page
|
|
* @page: the page
|
|
* @compound: charge the page as compound or small page
|
|
* @from: mem_cgroup which the page is moved from.
|
|
* @to: mem_cgroup which the page is moved to. @from != @to.
|
|
*
|
|
* The caller must make sure the page is not on LRU (isolate_page() is useful.)
|
|
*
|
|
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
|
|
* from old cgroup.
|
|
*/
|
|
static int mem_cgroup_move_account(struct page *page,
|
|
bool compound,
|
|
struct mem_cgroup *from,
|
|
struct mem_cgroup *to)
|
|
{
|
|
struct lruvec *from_vec, *to_vec;
|
|
struct pglist_data *pgdat;
|
|
unsigned int nr_pages = compound ? thp_nr_pages(page) : 1;
|
|
int ret;
|
|
|
|
VM_BUG_ON(from == to);
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
VM_BUG_ON(compound && !PageTransHuge(page));
|
|
|
|
/*
|
|
* Prevent mem_cgroup_migrate() from looking at
|
|
* page's memory cgroup of its source page while we change it.
|
|
*/
|
|
ret = -EBUSY;
|
|
if (!trylock_page(page))
|
|
goto out;
|
|
|
|
ret = -EINVAL;
|
|
if (page_memcg(page) != from)
|
|
goto out_unlock;
|
|
|
|
pgdat = page_pgdat(page);
|
|
from_vec = mem_cgroup_lruvec(from, pgdat);
|
|
to_vec = mem_cgroup_lruvec(to, pgdat);
|
|
|
|
lock_page_memcg(page);
|
|
|
|
if (PageAnon(page)) {
|
|
if (page_mapped(page)) {
|
|
__mod_lruvec_state(from_vec, NR_ANON_MAPPED, -nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_ANON_MAPPED, nr_pages);
|
|
if (PageTransHuge(page)) {
|
|
__mod_lruvec_state(from_vec, NR_ANON_THPS,
|
|
-nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_ANON_THPS,
|
|
nr_pages);
|
|
}
|
|
}
|
|
} else {
|
|
__mod_lruvec_state(from_vec, NR_FILE_PAGES, -nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_FILE_PAGES, nr_pages);
|
|
|
|
if (PageSwapBacked(page)) {
|
|
__mod_lruvec_state(from_vec, NR_SHMEM, -nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_SHMEM, nr_pages);
|
|
}
|
|
|
|
if (page_mapped(page)) {
|
|
__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
|
|
}
|
|
|
|
if (PageDirty(page)) {
|
|
struct address_space *mapping = page_mapping(page);
|
|
|
|
if (mapping_can_writeback(mapping)) {
|
|
__mod_lruvec_state(from_vec, NR_FILE_DIRTY,
|
|
-nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_FILE_DIRTY,
|
|
nr_pages);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (PageWriteback(page)) {
|
|
__mod_lruvec_state(from_vec, NR_WRITEBACK, -nr_pages);
|
|
__mod_lruvec_state(to_vec, NR_WRITEBACK, nr_pages);
|
|
}
|
|
|
|
/*
|
|
* All state has been migrated, let's switch to the new memcg.
|
|
*
|
|
* It is safe to change page's memcg here because the page
|
|
* is referenced, charged, isolated, and locked: we can't race
|
|
* with (un)charging, migration, LRU putback, or anything else
|
|
* that would rely on a stable page's memory cgroup.
|
|
*
|
|
* Note that lock_page_memcg is a memcg lock, not a page lock,
|
|
* to save space. As soon as we switch page's memory cgroup to a
|
|
* new memcg that isn't locked, the above state can change
|
|
* concurrently again. Make sure we're truly done with it.
|
|
*/
|
|
smp_mb();
|
|
|
|
css_get(&to->css);
|
|
css_put(&from->css);
|
|
|
|
page->memcg_data = (unsigned long)to;
|
|
|
|
__unlock_page_memcg(from);
|
|
|
|
ret = 0;
|
|
|
|
local_irq_disable();
|
|
mem_cgroup_charge_statistics(to, page, nr_pages);
|
|
memcg_check_events(to, page);
|
|
mem_cgroup_charge_statistics(from, page, -nr_pages);
|
|
memcg_check_events(from, page);
|
|
local_irq_enable();
|
|
out_unlock:
|
|
unlock_page(page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* get_mctgt_type - get target type of moving charge
|
|
* @vma: the vma the pte to be checked belongs
|
|
* @addr: the address corresponding to the pte to be checked
|
|
* @ptent: the pte to be checked
|
|
* @target: the pointer the target page or swap ent will be stored(can be NULL)
|
|
*
|
|
* Returns
|
|
* 0(MC_TARGET_NONE): if the pte is not a target for move charge.
|
|
* 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
|
|
* move charge. if @target is not NULL, the page is stored in target->page
|
|
* with extra refcnt got(Callers should handle it).
|
|
* 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
|
|
* target for charge migration. if @target is not NULL, the entry is stored
|
|
* in target->ent.
|
|
* 3(MC_TARGET_DEVICE): like MC_TARGET_PAGE but page is MEMORY_DEVICE_PRIVATE
|
|
* (so ZONE_DEVICE page and thus not on the lru).
|
|
* For now we such page is charge like a regular page would be as for all
|
|
* intent and purposes it is just special memory taking the place of a
|
|
* regular page.
|
|
*
|
|
* See Documentations/vm/hmm.txt and include/linux/hmm.h
|
|
*
|
|
* Called with pte lock held.
|
|
*/
|
|
|
|
static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
swp_entry_t ent = { .val = 0 };
|
|
|
|
if (pte_present(ptent))
|
|
page = mc_handle_present_pte(vma, addr, ptent);
|
|
else if (is_swap_pte(ptent))
|
|
page = mc_handle_swap_pte(vma, ptent, &ent);
|
|
else if (pte_none(ptent))
|
|
page = mc_handle_file_pte(vma, addr, ptent, &ent);
|
|
|
|
if (!page && !ent.val)
|
|
return ret;
|
|
if (page) {
|
|
/*
|
|
* Do only loose check w/o serialization.
|
|
* mem_cgroup_move_account() checks the page is valid or
|
|
* not under LRU exclusion.
|
|
*/
|
|
if (page_memcg(page) == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (is_device_private_page(page))
|
|
ret = MC_TARGET_DEVICE;
|
|
if (target)
|
|
target->page = page;
|
|
}
|
|
if (!ret || !target)
|
|
put_page(page);
|
|
}
|
|
/*
|
|
* There is a swap entry and a page doesn't exist or isn't charged.
|
|
* But we cannot move a tail-page in a THP.
|
|
*/
|
|
if (ent.val && !ret && (!page || !PageTransCompound(page)) &&
|
|
mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
|
|
ret = MC_TARGET_SWAP;
|
|
if (target)
|
|
target->ent = ent;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* We don't consider PMD mapped swapping or file mapped pages because THP does
|
|
* not support them for now.
|
|
* Caller should make sure that pmd_trans_huge(pmd) is true.
|
|
*/
|
|
static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
|
|
if (unlikely(is_swap_pmd(pmd))) {
|
|
VM_BUG_ON(thp_migration_supported() &&
|
|
!is_pmd_migration_entry(pmd));
|
|
return ret;
|
|
}
|
|
page = pmd_page(pmd);
|
|
VM_BUG_ON_PAGE(!page || !PageHead(page), page);
|
|
if (!(mc.flags & MOVE_ANON))
|
|
return ret;
|
|
if (page_memcg(page) == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target) {
|
|
get_page(page);
|
|
target->page = page;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
return MC_TARGET_NONE;
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
struct vm_area_struct *vma = walk->vma;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
|
|
ptl = pmd_trans_huge_lock(pmd, vma);
|
|
if (ptl) {
|
|
/*
|
|
* Note their can not be MC_TARGET_DEVICE for now as we do not
|
|
* support transparent huge page with MEMORY_DEVICE_PRIVATE but
|
|
* this might change.
|
|
*/
|
|
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
|
|
mc.precharge += HPAGE_PMD_NR;
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; pte++, addr += PAGE_SIZE)
|
|
if (get_mctgt_type(vma, addr, *pte, NULL))
|
|
mc.precharge++; /* increment precharge temporarily */
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct mm_walk_ops precharge_walk_ops = {
|
|
.pmd_entry = mem_cgroup_count_precharge_pte_range,
|
|
};
|
|
|
|
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge;
|
|
|
|
mmap_read_lock(mm);
|
|
walk_page_range(mm, 0, mm->highest_vm_end, &precharge_walk_ops, NULL);
|
|
mmap_read_unlock(mm);
|
|
|
|
precharge = mc.precharge;
|
|
mc.precharge = 0;
|
|
|
|
return precharge;
|
|
}
|
|
|
|
static int mem_cgroup_precharge_mc(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge = mem_cgroup_count_precharge(mm);
|
|
|
|
VM_BUG_ON(mc.moving_task);
|
|
mc.moving_task = current;
|
|
return mem_cgroup_do_precharge(precharge);
|
|
}
|
|
|
|
/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
|
|
static void __mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
struct mem_cgroup *to = mc.to;
|
|
|
|
/* we must uncharge all the leftover precharges from mc.to */
|
|
if (mc.precharge) {
|
|
cancel_charge(mc.to, mc.precharge);
|
|
mc.precharge = 0;
|
|
}
|
|
/*
|
|
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so
|
|
* we must uncharge here.
|
|
*/
|
|
if (mc.moved_charge) {
|
|
cancel_charge(mc.from, mc.moved_charge);
|
|
mc.moved_charge = 0;
|
|
}
|
|
/* we must fixup refcnts and charges */
|
|
if (mc.moved_swap) {
|
|
/* uncharge swap account from the old cgroup */
|
|
if (!mem_cgroup_is_root(mc.from))
|
|
page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
|
|
|
|
mem_cgroup_id_put_many(mc.from, mc.moved_swap);
|
|
|
|
/*
|
|
* we charged both to->memory and to->memsw, so we
|
|
* should uncharge to->memory.
|
|
*/
|
|
if (!mem_cgroup_is_root(mc.to))
|
|
page_counter_uncharge(&mc.to->memory, mc.moved_swap);
|
|
|
|
mc.moved_swap = 0;
|
|
}
|
|
memcg_oom_recover(from);
|
|
memcg_oom_recover(to);
|
|
wake_up_all(&mc.waitq);
|
|
}
|
|
|
|
static void mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mm_struct *mm = mc.mm;
|
|
|
|
/*
|
|
* we must clear moving_task before waking up waiters at the end of
|
|
* task migration.
|
|
*/
|
|
mc.moving_task = NULL;
|
|
__mem_cgroup_clear_mc();
|
|
spin_lock(&mc.lock);
|
|
mc.from = NULL;
|
|
mc.to = NULL;
|
|
mc.mm = NULL;
|
|
spin_unlock(&mc.lock);
|
|
|
|
mmput(mm);
|
|
}
|
|
|
|
static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
struct mem_cgroup *memcg = NULL; /* unneeded init to make gcc happy */
|
|
struct mem_cgroup *from;
|
|
struct task_struct *leader, *p;
|
|
struct mm_struct *mm;
|
|
unsigned long move_flags;
|
|
int ret = 0;
|
|
|
|
/* charge immigration isn't supported on the default hierarchy */
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return 0;
|
|
|
|
/*
|
|
* Multi-process migrations only happen on the default hierarchy
|
|
* where charge immigration is not used. Perform charge
|
|
* immigration if @tset contains a leader and whine if there are
|
|
* multiple.
|
|
*/
|
|
p = NULL;
|
|
cgroup_taskset_for_each_leader(leader, css, tset) {
|
|
WARN_ON_ONCE(p);
|
|
p = leader;
|
|
memcg = mem_cgroup_from_css(css);
|
|
}
|
|
if (!p)
|
|
return 0;
|
|
|
|
/*
|
|
* We are now committed to this value whatever it is. Changes in this
|
|
* tunable will only affect upcoming migrations, not the current one.
|
|
* So we need to save it, and keep it going.
|
|
*/
|
|
move_flags = READ_ONCE(memcg->move_charge_at_immigrate);
|
|
if (!move_flags)
|
|
return 0;
|
|
|
|
from = mem_cgroup_from_task(p);
|
|
|
|
VM_BUG_ON(from == memcg);
|
|
|
|
mm = get_task_mm(p);
|
|
if (!mm)
|
|
return 0;
|
|
/* We move charges only when we move a owner of the mm */
|
|
if (mm->owner == p) {
|
|
VM_BUG_ON(mc.from);
|
|
VM_BUG_ON(mc.to);
|
|
VM_BUG_ON(mc.precharge);
|
|
VM_BUG_ON(mc.moved_charge);
|
|
VM_BUG_ON(mc.moved_swap);
|
|
|
|
spin_lock(&mc.lock);
|
|
mc.mm = mm;
|
|
mc.from = from;
|
|
mc.to = memcg;
|
|
mc.flags = move_flags;
|
|
spin_unlock(&mc.lock);
|
|
/* We set mc.moving_task later */
|
|
|
|
ret = mem_cgroup_precharge_mc(mm);
|
|
if (ret)
|
|
mem_cgroup_clear_mc();
|
|
} else {
|
|
mmput(mm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
|
|
{
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
|
|
static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
int ret = 0;
|
|
struct vm_area_struct *vma = walk->vma;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
enum mc_target_type target_type;
|
|
union mc_target target;
|
|
struct page *page;
|
|
|
|
ptl = pmd_trans_huge_lock(pmd, vma);
|
|
if (ptl) {
|
|
if (mc.precharge < HPAGE_PMD_NR) {
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
|
|
if (target_type == MC_TARGET_PAGE) {
|
|
page = target.page;
|
|
if (!isolate_lru_page(page)) {
|
|
if (!mem_cgroup_move_account(page, true,
|
|
mc.from, mc.to)) {
|
|
mc.precharge -= HPAGE_PMD_NR;
|
|
mc.moved_charge += HPAGE_PMD_NR;
|
|
}
|
|
putback_lru_page(page);
|
|
}
|
|
put_page(page);
|
|
} else if (target_type == MC_TARGET_DEVICE) {
|
|
page = target.page;
|
|
if (!mem_cgroup_move_account(page, true,
|
|
mc.from, mc.to)) {
|
|
mc.precharge -= HPAGE_PMD_NR;
|
|
mc.moved_charge += HPAGE_PMD_NR;
|
|
}
|
|
put_page(page);
|
|
}
|
|
spin_unlock(ptl);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
retry:
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; addr += PAGE_SIZE) {
|
|
pte_t ptent = *(pte++);
|
|
bool device = false;
|
|
swp_entry_t ent;
|
|
|
|
if (!mc.precharge)
|
|
break;
|
|
|
|
switch (get_mctgt_type(vma, addr, ptent, &target)) {
|
|
case MC_TARGET_DEVICE:
|
|
device = true;
|
|
fallthrough;
|
|
case MC_TARGET_PAGE:
|
|
page = target.page;
|
|
/*
|
|
* We can have a part of the split pmd here. Moving it
|
|
* can be done but it would be too convoluted so simply
|
|
* ignore such a partial THP and keep it in original
|
|
* memcg. There should be somebody mapping the head.
|
|
*/
|
|
if (PageTransCompound(page))
|
|
goto put;
|
|
if (!device && isolate_lru_page(page))
|
|
goto put;
|
|
if (!mem_cgroup_move_account(page, false,
|
|
mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we uncharge from mc.from later. */
|
|
mc.moved_charge++;
|
|
}
|
|
if (!device)
|
|
putback_lru_page(page);
|
|
put: /* get_mctgt_type() gets the page */
|
|
put_page(page);
|
|
break;
|
|
case MC_TARGET_SWAP:
|
|
ent = target.ent;
|
|
if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
mem_cgroup_id_get_many(mc.to, 1);
|
|
/* we fixup other refcnts and charges later. */
|
|
mc.moved_swap++;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
if (addr != end) {
|
|
/*
|
|
* We have consumed all precharges we got in can_attach().
|
|
* We try charge one by one, but don't do any additional
|
|
* charges to mc.to if we have failed in charge once in attach()
|
|
* phase.
|
|
*/
|
|
ret = mem_cgroup_do_precharge(1);
|
|
if (!ret)
|
|
goto retry;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static const struct mm_walk_ops charge_walk_ops = {
|
|
.pmd_entry = mem_cgroup_move_charge_pte_range,
|
|
};
|
|
|
|
static void mem_cgroup_move_charge(void)
|
|
{
|
|
lru_add_drain_all();
|
|
/*
|
|
* Signal lock_page_memcg() to take the memcg's move_lock
|
|
* while we're moving its pages to another memcg. Then wait
|
|
* for already started RCU-only updates to finish.
|
|
*/
|
|
atomic_inc(&mc.from->moving_account);
|
|
synchronize_rcu();
|
|
retry:
|
|
if (unlikely(!mmap_read_trylock(mc.mm))) {
|
|
/*
|
|
* Someone who are holding the mmap_lock might be waiting in
|
|
* waitq. So we cancel all extra charges, wake up all waiters,
|
|
* and retry. Because we cancel precharges, we might not be able
|
|
* to move enough charges, but moving charge is a best-effort
|
|
* feature anyway, so it wouldn't be a big problem.
|
|
*/
|
|
__mem_cgroup_clear_mc();
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
/*
|
|
* When we have consumed all precharges and failed in doing
|
|
* additional charge, the page walk just aborts.
|
|
*/
|
|
walk_page_range(mc.mm, 0, mc.mm->highest_vm_end, &charge_walk_ops,
|
|
NULL);
|
|
|
|
mmap_read_unlock(mc.mm);
|
|
atomic_dec(&mc.from->moving_account);
|
|
}
|
|
|
|
static void mem_cgroup_move_task(void)
|
|
{
|
|
if (mc.to) {
|
|
mem_cgroup_move_charge();
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
static int mem_cgroup_can_attach(struct cgroup_taskset *tset)
|
|
{
|
|
return 0;
|
|
}
|
|
static void mem_cgroup_cancel_attach(struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
static void mem_cgroup_move_task(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value)
|
|
{
|
|
if (value == PAGE_COUNTER_MAX)
|
|
seq_puts(m, "max\n");
|
|
else
|
|
seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 memory_current_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return (u64)page_counter_read(&memcg->memory) * PAGE_SIZE;
|
|
}
|
|
|
|
static int memory_min_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.min));
|
|
}
|
|
|
|
static ssize_t memory_min_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long min;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &min);
|
|
if (err)
|
|
return err;
|
|
|
|
page_counter_set_min(&memcg->memory, min);
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static int memory_low_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.low));
|
|
}
|
|
|
|
static ssize_t memory_low_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long low;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &low);
|
|
if (err)
|
|
return err;
|
|
|
|
page_counter_set_low(&memcg->memory, low);
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static int memory_high_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.high));
|
|
}
|
|
|
|
static ssize_t memory_high_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned int nr_retries = MAX_RECLAIM_RETRIES;
|
|
bool drained = false;
|
|
unsigned long high;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &high);
|
|
if (err)
|
|
return err;
|
|
|
|
page_counter_set_high(&memcg->memory, high);
|
|
|
|
for (;;) {
|
|
unsigned long nr_pages = page_counter_read(&memcg->memory);
|
|
unsigned long reclaimed;
|
|
|
|
if (nr_pages <= high)
|
|
break;
|
|
|
|
if (signal_pending(current))
|
|
break;
|
|
|
|
if (!drained) {
|
|
drain_all_stock(memcg);
|
|
drained = true;
|
|
continue;
|
|
}
|
|
|
|
reclaimed = try_to_free_mem_cgroup_pages(memcg, nr_pages - high,
|
|
GFP_KERNEL, true);
|
|
|
|
if (!reclaimed && !nr_retries--)
|
|
break;
|
|
}
|
|
|
|
memcg_wb_domain_size_changed(memcg);
|
|
return nbytes;
|
|
}
|
|
|
|
static int memory_max_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->memory.max));
|
|
}
|
|
|
|
static ssize_t memory_max_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned int nr_reclaims = MAX_RECLAIM_RETRIES;
|
|
bool drained = false;
|
|
unsigned long max;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &max);
|
|
if (err)
|
|
return err;
|
|
|
|
xchg(&memcg->memory.max, max);
|
|
|
|
for (;;) {
|
|
unsigned long nr_pages = page_counter_read(&memcg->memory);
|
|
|
|
if (nr_pages <= max)
|
|
break;
|
|
|
|
if (signal_pending(current))
|
|
break;
|
|
|
|
if (!drained) {
|
|
drain_all_stock(memcg);
|
|
drained = true;
|
|
continue;
|
|
}
|
|
|
|
if (nr_reclaims) {
|
|
if (!try_to_free_mem_cgroup_pages(memcg, nr_pages - max,
|
|
GFP_KERNEL, true))
|
|
nr_reclaims--;
|
|
continue;
|
|
}
|
|
|
|
memcg_memory_event(memcg, MEMCG_OOM);
|
|
if (!mem_cgroup_out_of_memory(memcg, GFP_KERNEL, 0))
|
|
break;
|
|
}
|
|
|
|
memcg_wb_domain_size_changed(memcg);
|
|
return nbytes;
|
|
}
|
|
|
|
static void __memory_events_show(struct seq_file *m, atomic_long_t *events)
|
|
{
|
|
seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW]));
|
|
seq_printf(m, "high %lu\n", atomic_long_read(&events[MEMCG_HIGH]));
|
|
seq_printf(m, "max %lu\n", atomic_long_read(&events[MEMCG_MAX]));
|
|
seq_printf(m, "oom %lu\n", atomic_long_read(&events[MEMCG_OOM]));
|
|
seq_printf(m, "oom_kill %lu\n",
|
|
atomic_long_read(&events[MEMCG_OOM_KILL]));
|
|
}
|
|
|
|
static int memory_events_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
__memory_events_show(m, memcg->memory_events);
|
|
return 0;
|
|
}
|
|
|
|
static int memory_events_local_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
__memory_events_show(m, memcg->memory_events_local);
|
|
return 0;
|
|
}
|
|
|
|
static int memory_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
char *buf;
|
|
|
|
buf = memory_stat_format(memcg);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
seq_puts(m, buf);
|
|
kfree(buf);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static inline unsigned long lruvec_page_state_output(struct lruvec *lruvec,
|
|
int item)
|
|
{
|
|
return lruvec_page_state(lruvec, item) * memcg_page_state_unit(item);
|
|
}
|
|
|
|
static int memory_numa_stat_show(struct seq_file *m, void *v)
|
|
{
|
|
int i;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
cgroup_rstat_flush(memcg->css.cgroup);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(memory_stats); i++) {
|
|
int nid;
|
|
|
|
if (memory_stats[i].idx >= NR_VM_NODE_STAT_ITEMS)
|
|
continue;
|
|
|
|
seq_printf(m, "%s", memory_stats[i].name);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
u64 size;
|
|
struct lruvec *lruvec;
|
|
|
|
lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
|
|
size = lruvec_page_state_output(lruvec,
|
|
memory_stats[i].idx);
|
|
seq_printf(m, " N%d=%llu", nid, size);
|
|
}
|
|
seq_putc(m, '\n');
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int memory_oom_group_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
seq_printf(m, "%d\n", memcg->oom_group);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t memory_oom_group_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
int ret, oom_group;
|
|
|
|
buf = strstrip(buf);
|
|
if (!buf)
|
|
return -EINVAL;
|
|
|
|
ret = kstrtoint(buf, 0, &oom_group);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (oom_group != 0 && oom_group != 1)
|
|
return -EINVAL;
|
|
|
|
memcg->oom_group = oom_group;
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static struct cftype memory_files[] = {
|
|
{
|
|
.name = "current",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.read_u64 = memory_current_read,
|
|
},
|
|
{
|
|
.name = "min",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = memory_min_show,
|
|
.write = memory_min_write,
|
|
},
|
|
{
|
|
.name = "low",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = memory_low_show,
|
|
.write = memory_low_write,
|
|
},
|
|
{
|
|
.name = "high",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = memory_high_show,
|
|
.write = memory_high_write,
|
|
},
|
|
{
|
|
.name = "max",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = memory_max_show,
|
|
.write = memory_max_write,
|
|
},
|
|
{
|
|
.name = "events",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.file_offset = offsetof(struct mem_cgroup, events_file),
|
|
.seq_show = memory_events_show,
|
|
},
|
|
{
|
|
.name = "events.local",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.file_offset = offsetof(struct mem_cgroup, events_local_file),
|
|
.seq_show = memory_events_local_show,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.seq_show = memory_stat_show,
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.seq_show = memory_numa_stat_show,
|
|
},
|
|
#endif
|
|
{
|
|
.name = "oom.group",
|
|
.flags = CFTYPE_NOT_ON_ROOT | CFTYPE_NS_DELEGATABLE,
|
|
.seq_show = memory_oom_group_show,
|
|
.write = memory_oom_group_write,
|
|
},
|
|
{ } /* terminate */
|
|
};
|
|
|
|
struct cgroup_subsys memory_cgrp_subsys = {
|
|
.css_alloc = mem_cgroup_css_alloc,
|
|
.css_online = mem_cgroup_css_online,
|
|
.css_offline = mem_cgroup_css_offline,
|
|
.css_released = mem_cgroup_css_released,
|
|
.css_free = mem_cgroup_css_free,
|
|
.css_reset = mem_cgroup_css_reset,
|
|
.css_rstat_flush = mem_cgroup_css_rstat_flush,
|
|
.can_attach = mem_cgroup_can_attach,
|
|
.cancel_attach = mem_cgroup_cancel_attach,
|
|
.post_attach = mem_cgroup_move_task,
|
|
.dfl_cftypes = memory_files,
|
|
.legacy_cftypes = mem_cgroup_legacy_files,
|
|
.early_init = 0,
|
|
};
|
|
|
|
/*
|
|
* This function calculates an individual cgroup's effective
|
|
* protection which is derived from its own memory.min/low, its
|
|
* parent's and siblings' settings, as well as the actual memory
|
|
* distribution in the tree.
|
|
*
|
|
* The following rules apply to the effective protection values:
|
|
*
|
|
* 1. At the first level of reclaim, effective protection is equal to
|
|
* the declared protection in memory.min and memory.low.
|
|
*
|
|
* 2. To enable safe delegation of the protection configuration, at
|
|
* subsequent levels the effective protection is capped to the
|
|
* parent's effective protection.
|
|
*
|
|
* 3. To make complex and dynamic subtrees easier to configure, the
|
|
* user is allowed to overcommit the declared protection at a given
|
|
* level. If that is the case, the parent's effective protection is
|
|
* distributed to the children in proportion to how much protection
|
|
* they have declared and how much of it they are utilizing.
|
|
*
|
|
* This makes distribution proportional, but also work-conserving:
|
|
* if one cgroup claims much more protection than it uses memory,
|
|
* the unused remainder is available to its siblings.
|
|
*
|
|
* 4. Conversely, when the declared protection is undercommitted at a
|
|
* given level, the distribution of the larger parental protection
|
|
* budget is NOT proportional. A cgroup's protection from a sibling
|
|
* is capped to its own memory.min/low setting.
|
|
*
|
|
* 5. However, to allow protecting recursive subtrees from each other
|
|
* without having to declare each individual cgroup's fixed share
|
|
* of the ancestor's claim to protection, any unutilized -
|
|
* "floating" - protection from up the tree is distributed in
|
|
* proportion to each cgroup's *usage*. This makes the protection
|
|
* neutral wrt sibling cgroups and lets them compete freely over
|
|
* the shared parental protection budget, but it protects the
|
|
* subtree as a whole from neighboring subtrees.
|
|
*
|
|
* Note that 4. and 5. are not in conflict: 4. is about protecting
|
|
* against immediate siblings whereas 5. is about protecting against
|
|
* neighboring subtrees.
|
|
*/
|
|
static unsigned long effective_protection(unsigned long usage,
|
|
unsigned long parent_usage,
|
|
unsigned long setting,
|
|
unsigned long parent_effective,
|
|
unsigned long siblings_protected)
|
|
{
|
|
unsigned long protected;
|
|
unsigned long ep;
|
|
|
|
protected = min(usage, setting);
|
|
/*
|
|
* If all cgroups at this level combined claim and use more
|
|
* protection then what the parent affords them, distribute
|
|
* shares in proportion to utilization.
|
|
*
|
|
* We are using actual utilization rather than the statically
|
|
* claimed protection in order to be work-conserving: claimed
|
|
* but unused protection is available to siblings that would
|
|
* otherwise get a smaller chunk than what they claimed.
|
|
*/
|
|
if (siblings_protected > parent_effective)
|
|
return protected * parent_effective / siblings_protected;
|
|
|
|
/*
|
|
* Ok, utilized protection of all children is within what the
|
|
* parent affords them, so we know whatever this child claims
|
|
* and utilizes is effectively protected.
|
|
*
|
|
* If there is unprotected usage beyond this value, reclaim
|
|
* will apply pressure in proportion to that amount.
|
|
*
|
|
* If there is unutilized protection, the cgroup will be fully
|
|
* shielded from reclaim, but we do return a smaller value for
|
|
* protection than what the group could enjoy in theory. This
|
|
* is okay. With the overcommit distribution above, effective
|
|
* protection is always dependent on how memory is actually
|
|
* consumed among the siblings anyway.
|
|
*/
|
|
ep = protected;
|
|
|
|
/*
|
|
* If the children aren't claiming (all of) the protection
|
|
* afforded to them by the parent, distribute the remainder in
|
|
* proportion to the (unprotected) memory of each cgroup. That
|
|
* way, cgroups that aren't explicitly prioritized wrt each
|
|
* other compete freely over the allowance, but they are
|
|
* collectively protected from neighboring trees.
|
|
*
|
|
* We're using unprotected memory for the weight so that if
|
|
* some cgroups DO claim explicit protection, we don't protect
|
|
* the same bytes twice.
|
|
*
|
|
* Check both usage and parent_usage against the respective
|
|
* protected values. One should imply the other, but they
|
|
* aren't read atomically - make sure the division is sane.
|
|
*/
|
|
if (!(cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_RECURSIVE_PROT))
|
|
return ep;
|
|
if (parent_effective > siblings_protected &&
|
|
parent_usage > siblings_protected &&
|
|
usage > protected) {
|
|
unsigned long unclaimed;
|
|
|
|
unclaimed = parent_effective - siblings_protected;
|
|
unclaimed *= usage - protected;
|
|
unclaimed /= parent_usage - siblings_protected;
|
|
|
|
ep += unclaimed;
|
|
}
|
|
|
|
return ep;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_calculate_protection - check if memory consumption is in the normal range
|
|
* @root: the top ancestor of the sub-tree being checked
|
|
* @memcg: the memory cgroup to check
|
|
*
|
|
* WARNING: This function is not stateless! It can only be used as part
|
|
* of a top-down tree iteration, not for isolated queries.
|
|
*/
|
|
void mem_cgroup_calculate_protection(struct mem_cgroup *root,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long usage, parent_usage;
|
|
struct mem_cgroup *parent;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
/*
|
|
* Effective values of the reclaim targets are ignored so they
|
|
* can be stale. Have a look at mem_cgroup_protection for more
|
|
* details.
|
|
* TODO: calculation should be more robust so that we do not need
|
|
* that special casing.
|
|
*/
|
|
if (memcg == root)
|
|
return;
|
|
|
|
usage = page_counter_read(&memcg->memory);
|
|
if (!usage)
|
|
return;
|
|
|
|
parent = parent_mem_cgroup(memcg);
|
|
/* No parent means a non-hierarchical mode on v1 memcg */
|
|
if (!parent)
|
|
return;
|
|
|
|
if (parent == root) {
|
|
memcg->memory.emin = READ_ONCE(memcg->memory.min);
|
|
memcg->memory.elow = READ_ONCE(memcg->memory.low);
|
|
return;
|
|
}
|
|
|
|
parent_usage = page_counter_read(&parent->memory);
|
|
|
|
WRITE_ONCE(memcg->memory.emin, effective_protection(usage, parent_usage,
|
|
READ_ONCE(memcg->memory.min),
|
|
READ_ONCE(parent->memory.emin),
|
|
atomic_long_read(&parent->memory.children_min_usage)));
|
|
|
|
WRITE_ONCE(memcg->memory.elow, effective_protection(usage, parent_usage,
|
|
READ_ONCE(memcg->memory.low),
|
|
READ_ONCE(parent->memory.elow),
|
|
atomic_long_read(&parent->memory.children_low_usage)));
|
|
}
|
|
|
|
static int charge_memcg(struct page *page, struct mem_cgroup *memcg, gfp_t gfp)
|
|
{
|
|
unsigned int nr_pages = thp_nr_pages(page);
|
|
int ret;
|
|
|
|
ret = try_charge(memcg, gfp, nr_pages);
|
|
if (ret)
|
|
goto out;
|
|
|
|
css_get(&memcg->css);
|
|
commit_charge(page, memcg);
|
|
|
|
local_irq_disable();
|
|
mem_cgroup_charge_statistics(memcg, page, nr_pages);
|
|
memcg_check_events(memcg, page);
|
|
local_irq_enable();
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __mem_cgroup_charge - charge a newly allocated page to a cgroup
|
|
* @page: page to charge
|
|
* @mm: mm context of the victim
|
|
* @gfp_mask: reclaim mode
|
|
*
|
|
* Try to charge @page to the memcg that @mm belongs to, reclaiming
|
|
* pages according to @gfp_mask if necessary. if @mm is NULL, try to
|
|
* charge to the active memcg.
|
|
*
|
|
* Do not use this for pages allocated for swapin.
|
|
*
|
|
* Returns 0 on success. Otherwise, an error code is returned.
|
|
*/
|
|
int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
memcg = get_mem_cgroup_from_mm(mm);
|
|
ret = charge_memcg(page, memcg, gfp_mask);
|
|
css_put(&memcg->css);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_swapin_charge_page - charge a newly allocated page for swapin
|
|
* @page: page to charge
|
|
* @mm: mm context of the victim
|
|
* @gfp: reclaim mode
|
|
* @entry: swap entry for which the page is allocated
|
|
*
|
|
* This function charges a page allocated for swapin. Please call this before
|
|
* adding the page to the swapcache.
|
|
*
|
|
* Returns 0 on success. Otherwise, an error code is returned.
|
|
*/
|
|
int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp, swp_entry_t entry)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
int ret;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
|
|
id = lookup_swap_cgroup_id(entry);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_id(id);
|
|
if (!memcg || !css_tryget_online(&memcg->css))
|
|
memcg = get_mem_cgroup_from_mm(mm);
|
|
rcu_read_unlock();
|
|
|
|
ret = charge_memcg(page, memcg, gfp);
|
|
|
|
css_put(&memcg->css);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* mem_cgroup_swapin_uncharge_swap - uncharge swap slot
|
|
* @entry: swap entry for which the page is charged
|
|
*
|
|
* Call this function after successfully adding the charged page to swapcache.
|
|
*
|
|
* Note: This function assumes the page for which swap slot is being uncharged
|
|
* is order 0 page.
|
|
*/
|
|
void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry)
|
|
{
|
|
/*
|
|
* Cgroup1's unified memory+swap counter has been charged with the
|
|
* new swapcache page, finish the transfer by uncharging the swap
|
|
* slot. The swap slot would also get uncharged when it dies, but
|
|
* it can stick around indefinitely and we'd count the page twice
|
|
* the entire time.
|
|
*
|
|
* Cgroup2 has separate resource counters for memory and swap,
|
|
* so this is a non-issue here. Memory and swap charge lifetimes
|
|
* correspond 1:1 to page and swap slot lifetimes: we charge the
|
|
* page to memory here, and uncharge swap when the slot is freed.
|
|
*/
|
|
if (!mem_cgroup_disabled() && do_memsw_account()) {
|
|
/*
|
|
* The swap entry might not get freed for a long time,
|
|
* let's not wait for it. The page already received a
|
|
* memory+swap charge, drop the swap entry duplicate.
|
|
*/
|
|
mem_cgroup_uncharge_swap(entry, 1);
|
|
}
|
|
}
|
|
|
|
struct uncharge_gather {
|
|
struct mem_cgroup *memcg;
|
|
unsigned long nr_memory;
|
|
unsigned long pgpgout;
|
|
unsigned long nr_kmem;
|
|
struct page *dummy_page;
|
|
};
|
|
|
|
static inline void uncharge_gather_clear(struct uncharge_gather *ug)
|
|
{
|
|
memset(ug, 0, sizeof(*ug));
|
|
}
|
|
|
|
static void uncharge_batch(const struct uncharge_gather *ug)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (ug->nr_memory) {
|
|
page_counter_uncharge(&ug->memcg->memory, ug->nr_memory);
|
|
if (do_memsw_account())
|
|
page_counter_uncharge(&ug->memcg->memsw, ug->nr_memory);
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && ug->nr_kmem)
|
|
page_counter_uncharge(&ug->memcg->kmem, ug->nr_kmem);
|
|
memcg_oom_recover(ug->memcg);
|
|
}
|
|
|
|
local_irq_save(flags);
|
|
__count_memcg_events(ug->memcg, PGPGOUT, ug->pgpgout);
|
|
__this_cpu_add(ug->memcg->vmstats_percpu->nr_page_events, ug->nr_memory);
|
|
memcg_check_events(ug->memcg, ug->dummy_page);
|
|
local_irq_restore(flags);
|
|
|
|
/* drop reference from uncharge_page */
|
|
css_put(&ug->memcg->css);
|
|
}
|
|
|
|
static void uncharge_page(struct page *page, struct uncharge_gather *ug)
|
|
{
|
|
unsigned long nr_pages;
|
|
struct mem_cgroup *memcg;
|
|
struct obj_cgroup *objcg;
|
|
bool use_objcg = PageMemcgKmem(page);
|
|
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
|
|
/*
|
|
* Nobody should be changing or seriously looking at
|
|
* page memcg or objcg at this point, we have fully
|
|
* exclusive access to the page.
|
|
*/
|
|
if (use_objcg) {
|
|
objcg = __page_objcg(page);
|
|
/*
|
|
* This get matches the put at the end of the function and
|
|
* kmem pages do not hold memcg references anymore.
|
|
*/
|
|
memcg = get_mem_cgroup_from_objcg(objcg);
|
|
} else {
|
|
memcg = __page_memcg(page);
|
|
}
|
|
|
|
if (!memcg)
|
|
return;
|
|
|
|
if (ug->memcg != memcg) {
|
|
if (ug->memcg) {
|
|
uncharge_batch(ug);
|
|
uncharge_gather_clear(ug);
|
|
}
|
|
ug->memcg = memcg;
|
|
ug->dummy_page = page;
|
|
|
|
/* pairs with css_put in uncharge_batch */
|
|
css_get(&memcg->css);
|
|
}
|
|
|
|
nr_pages = compound_nr(page);
|
|
|
|
if (use_objcg) {
|
|
ug->nr_memory += nr_pages;
|
|
ug->nr_kmem += nr_pages;
|
|
|
|
page->memcg_data = 0;
|
|
obj_cgroup_put(objcg);
|
|
} else {
|
|
/* LRU pages aren't accounted at the root level */
|
|
if (!mem_cgroup_is_root(memcg))
|
|
ug->nr_memory += nr_pages;
|
|
ug->pgpgout++;
|
|
|
|
page->memcg_data = 0;
|
|
}
|
|
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/**
|
|
* __mem_cgroup_uncharge - uncharge a page
|
|
* @page: page to uncharge
|
|
*
|
|
* Uncharge a page previously charged with __mem_cgroup_charge().
|
|
*/
|
|
void __mem_cgroup_uncharge(struct page *page)
|
|
{
|
|
struct uncharge_gather ug;
|
|
|
|
/* Don't touch page->lru of any random page, pre-check: */
|
|
if (!page_memcg(page))
|
|
return;
|
|
|
|
uncharge_gather_clear(&ug);
|
|
uncharge_page(page, &ug);
|
|
uncharge_batch(&ug);
|
|
}
|
|
|
|
/**
|
|
* __mem_cgroup_uncharge_list - uncharge a list of page
|
|
* @page_list: list of pages to uncharge
|
|
*
|
|
* Uncharge a list of pages previously charged with
|
|
* __mem_cgroup_charge().
|
|
*/
|
|
void __mem_cgroup_uncharge_list(struct list_head *page_list)
|
|
{
|
|
struct uncharge_gather ug;
|
|
struct page *page;
|
|
|
|
uncharge_gather_clear(&ug);
|
|
list_for_each_entry(page, page_list, lru)
|
|
uncharge_page(page, &ug);
|
|
if (ug.memcg)
|
|
uncharge_batch(&ug);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_migrate - charge a page's replacement
|
|
* @oldpage: currently circulating page
|
|
* @newpage: replacement page
|
|
*
|
|
* Charge @newpage as a replacement page for @oldpage. @oldpage will
|
|
* be uncharged upon free.
|
|
*
|
|
* Both pages must be locked, @newpage->mapping must be set up.
|
|
*/
|
|
void mem_cgroup_migrate(struct page *oldpage, struct page *newpage)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned int nr_pages;
|
|
unsigned long flags;
|
|
|
|
VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
|
|
VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
|
|
VM_BUG_ON_PAGE(PageAnon(oldpage) != PageAnon(newpage), newpage);
|
|
VM_BUG_ON_PAGE(PageTransHuge(oldpage) != PageTransHuge(newpage),
|
|
newpage);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
/* Page cache replacement: new page already charged? */
|
|
if (page_memcg(newpage))
|
|
return;
|
|
|
|
memcg = page_memcg(oldpage);
|
|
VM_WARN_ON_ONCE_PAGE(!memcg, oldpage);
|
|
if (!memcg)
|
|
return;
|
|
|
|
/* Force-charge the new page. The old one will be freed soon */
|
|
nr_pages = thp_nr_pages(newpage);
|
|
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
page_counter_charge(&memcg->memory, nr_pages);
|
|
if (do_memsw_account())
|
|
page_counter_charge(&memcg->memsw, nr_pages);
|
|
}
|
|
|
|
css_get(&memcg->css);
|
|
commit_charge(newpage, memcg);
|
|
|
|
local_irq_save(flags);
|
|
mem_cgroup_charge_statistics(memcg, newpage, nr_pages);
|
|
memcg_check_events(memcg, newpage);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key);
|
|
EXPORT_SYMBOL(memcg_sockets_enabled_key);
|
|
|
|
void mem_cgroup_sk_alloc(struct sock *sk)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
if (!mem_cgroup_sockets_enabled)
|
|
return;
|
|
|
|
/* Do not associate the sock with unrelated interrupted task's memcg. */
|
|
if (in_interrupt())
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(current);
|
|
if (memcg == root_mem_cgroup)
|
|
goto out;
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active)
|
|
goto out;
|
|
if (css_tryget(&memcg->css))
|
|
sk->sk_memcg = memcg;
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
void mem_cgroup_sk_free(struct sock *sk)
|
|
{
|
|
if (sk->sk_memcg)
|
|
css_put(&sk->sk_memcg->css);
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_charge_skmem - charge socket memory
|
|
* @memcg: memcg to charge
|
|
* @nr_pages: number of pages to charge
|
|
* @gfp_mask: reclaim mode
|
|
*
|
|
* Charges @nr_pages to @memcg. Returns %true if the charge fit within
|
|
* @memcg's configured limit, %false if it doesn't.
|
|
*/
|
|
bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
|
|
gfp_t gfp_mask)
|
|
{
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
|
|
struct page_counter *fail;
|
|
|
|
if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
|
|
memcg->tcpmem_pressure = 0;
|
|
return true;
|
|
}
|
|
memcg->tcpmem_pressure = 1;
|
|
if (gfp_mask & __GFP_NOFAIL) {
|
|
page_counter_charge(&memcg->tcpmem, nr_pages);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
if (try_charge(memcg, gfp_mask, nr_pages) == 0) {
|
|
mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_uncharge_skmem - uncharge socket memory
|
|
* @memcg: memcg to uncharge
|
|
* @nr_pages: number of pages to uncharge
|
|
*/
|
|
void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
|
|
page_counter_uncharge(&memcg->tcpmem, nr_pages);
|
|
return;
|
|
}
|
|
|
|
mod_memcg_state(memcg, MEMCG_SOCK, -nr_pages);
|
|
|
|
refill_stock(memcg, nr_pages);
|
|
}
|
|
|
|
static int __init cgroup_memory(char *s)
|
|
{
|
|
char *token;
|
|
|
|
while ((token = strsep(&s, ",")) != NULL) {
|
|
if (!*token)
|
|
continue;
|
|
if (!strcmp(token, "nosocket"))
|
|
cgroup_memory_nosocket = true;
|
|
if (!strcmp(token, "nokmem"))
|
|
cgroup_memory_nokmem = true;
|
|
}
|
|
return 0;
|
|
}
|
|
__setup("cgroup.memory=", cgroup_memory);
|
|
|
|
/*
|
|
* subsys_initcall() for memory controller.
|
|
*
|
|
* Some parts like memcg_hotplug_cpu_dead() have to be initialized from this
|
|
* context because of lock dependencies (cgroup_lock -> cpu hotplug) but
|
|
* basically everything that doesn't depend on a specific mem_cgroup structure
|
|
* should be initialized from here.
|
|
*/
|
|
static int __init mem_cgroup_init(void)
|
|
{
|
|
int cpu, node;
|
|
|
|
/*
|
|
* Currently s32 type (can refer to struct batched_lruvec_stat) is
|
|
* used for per-memcg-per-cpu caching of per-node statistics. In order
|
|
* to work fine, we should make sure that the overfill threshold can't
|
|
* exceed S32_MAX / PAGE_SIZE.
|
|
*/
|
|
BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S32_MAX / PAGE_SIZE);
|
|
|
|
cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL,
|
|
memcg_hotplug_cpu_dead);
|
|
|
|
for_each_possible_cpu(cpu)
|
|
INIT_WORK(&per_cpu_ptr(&memcg_stock, cpu)->work,
|
|
drain_local_stock);
|
|
|
|
for_each_node(node) {
|
|
struct mem_cgroup_tree_per_node *rtpn;
|
|
|
|
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL,
|
|
node_online(node) ? node : NUMA_NO_NODE);
|
|
|
|
rtpn->rb_root = RB_ROOT;
|
|
rtpn->rb_rightmost = NULL;
|
|
spin_lock_init(&rtpn->lock);
|
|
soft_limit_tree.rb_tree_per_node[node] = rtpn;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(mem_cgroup_init);
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
|
|
{
|
|
while (!refcount_inc_not_zero(&memcg->id.ref)) {
|
|
/*
|
|
* The root cgroup cannot be destroyed, so it's refcount must
|
|
* always be >= 1.
|
|
*/
|
|
if (WARN_ON_ONCE(memcg == root_mem_cgroup)) {
|
|
VM_BUG_ON(1);
|
|
break;
|
|
}
|
|
memcg = parent_mem_cgroup(memcg);
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
}
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_swapout - transfer a memsw charge to swap
|
|
* @page: page whose memsw charge to transfer
|
|
* @entry: swap entry to move the charge to
|
|
*
|
|
* Transfer the memsw charge of @page to @entry.
|
|
*/
|
|
void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
|
|
{
|
|
struct mem_cgroup *memcg, *swap_memcg;
|
|
unsigned int nr_entries;
|
|
unsigned short oldid;
|
|
|
|
VM_BUG_ON_PAGE(PageLRU(page), page);
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return;
|
|
|
|
memcg = page_memcg(page);
|
|
|
|
VM_WARN_ON_ONCE_PAGE(!memcg, page);
|
|
if (!memcg)
|
|
return;
|
|
|
|
/*
|
|
* In case the memcg owning these pages has been offlined and doesn't
|
|
* have an ID allocated to it anymore, charge the closest online
|
|
* ancestor for the swap instead and transfer the memory+swap charge.
|
|
*/
|
|
swap_memcg = mem_cgroup_id_get_online(memcg);
|
|
nr_entries = thp_nr_pages(page);
|
|
/* Get references for the tail pages, too */
|
|
if (nr_entries > 1)
|
|
mem_cgroup_id_get_many(swap_memcg, nr_entries - 1);
|
|
oldid = swap_cgroup_record(entry, mem_cgroup_id(swap_memcg),
|
|
nr_entries);
|
|
VM_BUG_ON_PAGE(oldid, page);
|
|
mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries);
|
|
|
|
page->memcg_data = 0;
|
|
|
|
if (!mem_cgroup_is_root(memcg))
|
|
page_counter_uncharge(&memcg->memory, nr_entries);
|
|
|
|
if (!cgroup_memory_noswap && memcg != swap_memcg) {
|
|
if (!mem_cgroup_is_root(swap_memcg))
|
|
page_counter_charge(&swap_memcg->memsw, nr_entries);
|
|
page_counter_uncharge(&memcg->memsw, nr_entries);
|
|
}
|
|
|
|
/*
|
|
* Interrupts should be disabled here because the caller holds the
|
|
* i_pages lock which is taken with interrupts-off. It is
|
|
* important here to have the interrupts disabled because it is the
|
|
* only synchronisation we have for updating the per-CPU variables.
|
|
*/
|
|
VM_BUG_ON(!irqs_disabled());
|
|
mem_cgroup_charge_statistics(memcg, page, -nr_entries);
|
|
memcg_check_events(memcg, page);
|
|
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
/**
|
|
* __mem_cgroup_try_charge_swap - try charging swap space for a page
|
|
* @page: page being added to swap
|
|
* @entry: swap entry to charge
|
|
*
|
|
* Try to charge @page's memcg for the swap space at @entry.
|
|
*
|
|
* Returns 0 on success, -ENOMEM on failure.
|
|
*/
|
|
int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
|
|
{
|
|
unsigned int nr_pages = thp_nr_pages(page);
|
|
struct page_counter *counter;
|
|
struct mem_cgroup *memcg;
|
|
unsigned short oldid;
|
|
|
|
if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return 0;
|
|
|
|
memcg = page_memcg(page);
|
|
|
|
VM_WARN_ON_ONCE_PAGE(!memcg, page);
|
|
if (!memcg)
|
|
return 0;
|
|
|
|
if (!entry.val) {
|
|
memcg_memory_event(memcg, MEMCG_SWAP_FAIL);
|
|
return 0;
|
|
}
|
|
|
|
memcg = mem_cgroup_id_get_online(memcg);
|
|
|
|
if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg) &&
|
|
!page_counter_try_charge(&memcg->swap, nr_pages, &counter)) {
|
|
memcg_memory_event(memcg, MEMCG_SWAP_MAX);
|
|
memcg_memory_event(memcg, MEMCG_SWAP_FAIL);
|
|
mem_cgroup_id_put(memcg);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Get references for the tail pages, too */
|
|
if (nr_pages > 1)
|
|
mem_cgroup_id_get_many(memcg, nr_pages - 1);
|
|
oldid = swap_cgroup_record(entry, mem_cgroup_id(memcg), nr_pages);
|
|
VM_BUG_ON_PAGE(oldid, page);
|
|
mod_memcg_state(memcg, MEMCG_SWAP, nr_pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __mem_cgroup_uncharge_swap - uncharge swap space
|
|
* @entry: swap entry to uncharge
|
|
* @nr_pages: the amount of swap space to uncharge
|
|
*/
|
|
void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
|
|
id = swap_cgroup_record(entry, 0, nr_pages);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_id(id);
|
|
if (memcg) {
|
|
if (!cgroup_memory_noswap && !mem_cgroup_is_root(memcg)) {
|
|
if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
page_counter_uncharge(&memcg->swap, nr_pages);
|
|
else
|
|
page_counter_uncharge(&memcg->memsw, nr_pages);
|
|
}
|
|
mod_memcg_state(memcg, MEMCG_SWAP, -nr_pages);
|
|
mem_cgroup_id_put_many(memcg, nr_pages);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg)
|
|
{
|
|
long nr_swap_pages = get_nr_swap_pages();
|
|
|
|
if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return nr_swap_pages;
|
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg))
|
|
nr_swap_pages = min_t(long, nr_swap_pages,
|
|
READ_ONCE(memcg->swap.max) -
|
|
page_counter_read(&memcg->swap));
|
|
return nr_swap_pages;
|
|
}
|
|
|
|
bool mem_cgroup_swap_full(struct page *page)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
VM_BUG_ON_PAGE(!PageLocked(page), page);
|
|
|
|
if (vm_swap_full())
|
|
return true;
|
|
if (cgroup_memory_noswap || !cgroup_subsys_on_dfl(memory_cgrp_subsys))
|
|
return false;
|
|
|
|
memcg = page_memcg(page);
|
|
if (!memcg)
|
|
return false;
|
|
|
|
for (; memcg != root_mem_cgroup; memcg = parent_mem_cgroup(memcg)) {
|
|
unsigned long usage = page_counter_read(&memcg->swap);
|
|
|
|
if (usage * 2 >= READ_ONCE(memcg->swap.high) ||
|
|
usage * 2 >= READ_ONCE(memcg->swap.max))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static int __init setup_swap_account(char *s)
|
|
{
|
|
if (!strcmp(s, "1"))
|
|
cgroup_memory_noswap = false;
|
|
else if (!strcmp(s, "0"))
|
|
cgroup_memory_noswap = true;
|
|
return 1;
|
|
}
|
|
__setup("swapaccount=", setup_swap_account);
|
|
|
|
static u64 swap_current_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return (u64)page_counter_read(&memcg->swap) * PAGE_SIZE;
|
|
}
|
|
|
|
static int swap_high_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->swap.high));
|
|
}
|
|
|
|
static ssize_t swap_high_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long high;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &high);
|
|
if (err)
|
|
return err;
|
|
|
|
page_counter_set_high(&memcg->swap, high);
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static int swap_max_show(struct seq_file *m, void *v)
|
|
{
|
|
return seq_puts_memcg_tunable(m,
|
|
READ_ONCE(mem_cgroup_from_seq(m)->swap.max));
|
|
}
|
|
|
|
static ssize_t swap_max_write(struct kernfs_open_file *of,
|
|
char *buf, size_t nbytes, loff_t off)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
|
|
unsigned long max;
|
|
int err;
|
|
|
|
buf = strstrip(buf);
|
|
err = page_counter_memparse(buf, "max", &max);
|
|
if (err)
|
|
return err;
|
|
|
|
xchg(&memcg->swap.max, max);
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static int swap_events_show(struct seq_file *m, void *v)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
|
|
|
|
seq_printf(m, "high %lu\n",
|
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_HIGH]));
|
|
seq_printf(m, "max %lu\n",
|
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX]));
|
|
seq_printf(m, "fail %lu\n",
|
|
atomic_long_read(&memcg->memory_events[MEMCG_SWAP_FAIL]));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct cftype swap_files[] = {
|
|
{
|
|
.name = "swap.current",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.read_u64 = swap_current_read,
|
|
},
|
|
{
|
|
.name = "swap.high",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = swap_high_show,
|
|
.write = swap_high_write,
|
|
},
|
|
{
|
|
.name = "swap.max",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.seq_show = swap_max_show,
|
|
.write = swap_max_write,
|
|
},
|
|
{
|
|
.name = "swap.events",
|
|
.flags = CFTYPE_NOT_ON_ROOT,
|
|
.file_offset = offsetof(struct mem_cgroup, swap_events_file),
|
|
.seq_show = swap_events_show,
|
|
},
|
|
{ } /* terminate */
|
|
};
|
|
|
|
static struct cftype memsw_files[] = {
|
|
{
|
|
.name = "memsw.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
|
|
.write = mem_cgroup_write,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{
|
|
.name = "memsw.failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
|
|
.write = mem_cgroup_reset,
|
|
.read_u64 = mem_cgroup_read_u64,
|
|
},
|
|
{ }, /* terminate */
|
|
};
|
|
|
|
/*
|
|
* If mem_cgroup_swap_init() is implemented as a subsys_initcall()
|
|
* instead of a core_initcall(), this could mean cgroup_memory_noswap still
|
|
* remains set to false even when memcg is disabled via "cgroup_disable=memory"
|
|
* boot parameter. This may result in premature OOPS inside
|
|
* mem_cgroup_get_nr_swap_pages() function in corner cases.
|
|
*/
|
|
static int __init mem_cgroup_swap_init(void)
|
|
{
|
|
/* No memory control -> no swap control */
|
|
if (mem_cgroup_disabled())
|
|
cgroup_memory_noswap = true;
|
|
|
|
if (cgroup_memory_noswap)
|
|
return 0;
|
|
|
|
WARN_ON(cgroup_add_dfl_cftypes(&memory_cgrp_subsys, swap_files));
|
|
WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, memsw_files));
|
|
|
|
return 0;
|
|
}
|
|
core_initcall(mem_cgroup_swap_init);
|
|
|
|
#endif /* CONFIG_MEMCG_SWAP */
|