Roman Gushchin 00d484f354 mm: memcg: switch to css_tryget() in get_mem_cgroup_from_mm() ... We've encountered a rcu stall in get_mem_cgroup_from_mm(): rcu: INFO: rcu_sched self-detected stall on CPU rcu: 33-....: (21000 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=35441/35441 fqs=5017 (t=21031 jiffies g=324821 q=95837) NMI backtrace for cpu 33 <...> RIP: 0010:get_mem_cgroup_from_mm+0x2f/0x90 <...> __memcg_kmem_charge+0x55/0x140 __alloc_pages_nodemask+0x267/0x320 pipe_write+0x1ad/0x400 new_sync_write+0x127/0x1c0 __kernel_write+0x4f/0xf0 dump_emit+0x91/0xc0 writenote+0xa0/0xc0 elf_core_dump+0x11af/0x1430 do_coredump+0xc65/0xee0 get_signal+0x132/0x7c0 do_signal+0x36/0x640 exit_to_usermode_loop+0x61/0xd0 do_syscall_64+0xd4/0x100 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The problem is caused by an exiting task which is associated with an offline memcg. We're iterating over and over in the do {} while (!css_tryget_online()) loop, but obviously the memcg won't become online and the exiting task won't be migrated to a live memcg. Let's fix it by switching from css_tryget_online() to css_tryget(). As css_tryget_online() cannot guarantee that the memcg won't go offline, the check is usually useless, except some rare cases when for example it determines if something should be presented to a user. A similar problem is described by commit 18fa84a2db ("cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()"). Johannes: : The bug aside, it doesn't matter whether the cgroup is online for the : callers. It used to matter when offlining needed to evacuate all charges : from the memcg, and so needed to prevent new ones from showing up, but we : don't care now. Link: http://lkml.kernel.org/r/20191106225131.3543616-1-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Shakeel Butt <shakeeb@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2019-11-15 18:34:00 -08:00
..
kasan	mm: introduce compound_nr()	2019-09-24 15:54:08 -07:00
backing-dev.c	bdi: Do not use freezable workqueue	2019-10-06 09:11:35 -06:00
balloon_compaction.c	mm/balloon_compaction: suppress allocation warnings	2019-09-04 07:42:01 -04:00
cleancache.c	Driver Core and debugfs changes for 5.3-rc1	2019-07-12 12:24:03 -07:00
cma_debug.c	mm/cma_debug.c: fix the break condition in cma_maxchunk_get()	2019-05-14 09:47:45 -07:00
cma.c	mm/cma.c: fail if fixed declaration can't be honored	2019-07-16 19:23:21 -07:00
cma.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
compaction.c	mm, compaction: fix wrong pfn handling in __reset_isolation_pfn()	2019-10-14 15:04:01 -07:00
debug_page_ref.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
debug.c	mm: update references to page _refcount	2019-05-14 19:52:47 -07:00
dmapool.c	mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options	2019-07-12 11:05:46 -07:00
early_ioremap.c	mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep	2017-12-11 14:54:44 +01:00
fadvise.c	fs: Export generic_fadvise()	2019-08-30 22:43:58 -07:00
failslab.c	mm/failslab.c: by default, do not fail allocations with direct reclaim only	2019-07-12 11:05:43 -07:00
filemap.c	mm/filemap.c: include <linux/ramfs.h> for generic_file_vm_ops definition	2019-10-19 06:32:32 -04:00
frame_vector.c	mm: untag user pointers in get_vaddr_frames	2019-09-25 17:51:41 -07:00
frontswap.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482	2019-06-19 17:09:52 +02:00
gup_benchmark.c	mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM	2019-05-14 09:47:45 -07:00
gup.c	mm/gup: fix a misnamed "write" argument, and a related bug	2019-10-19 06:32:32 -04:00
highmem.c	mm: convert totalram_pages and totalhigh_pages variables to atomic	2018-12-28 12:11:47 -08:00
hmm.c	pagewalk: separate function pointers from iterator data	2019-09-07 04:28:04 -03:00
huge_memory.c	mm/thp: fix node page state in split_huge_page_to_list()	2019-10-19 06:32:32 -04:00
hugetlb_cgroup.c	mm: introduce compound_nr()	2019-09-24 15:54:08 -07:00
hugetlb.c	hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic()	2019-10-19 06:32:32 -04:00
hwpoison-inject.c	hwpoison-inject: no need to check return value of debugfs_create functions	2019-06-03 15:39:40 +02:00
init-mm.c	mm/init-mm.c: include <linux/mman.h> for vm_committed_as_batch	2019-10-19 06:32:32 -04:00
internal.h	mm: introduce MADV_COLD	2019-09-25 17:51:41 -07:00
interval_tree.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248	2019-06-19 17:09:08 +02:00
Kconfig	mm,thp: add read-only THP support for (non-shmem) FS	2019-09-24 15:54:11 -07:00
Kconfig.debug	mm, page_owner, debug_pagealloc: save and dump freeing stack trace	2019-09-24 15:54:08 -07:00
khugepaged.c	mm/khugepaged: fix might_sleep() warn with CONFIG_HIGHPTE=y	2019-11-06 08:47:50 -08:00
kmemleak-test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333	2019-06-05 17:37:06 +02:00
kmemleak.c	kmemleak: Do not corrupt the object_list during clean-up	2019-10-14 08:56:16 -07:00
ksm.c	mm: move memcmp_pages() and pages_identical()	2019-09-24 15:54:11 -07:00
list_lru.c	mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages	2019-07-12 11:05:44 -07:00
maccess.c	The main changes in this release include:	2019-07-18 11:51:00 -07:00
madvise.c	mm: fix trying to reclaim unevictable lru page when calling madvise_pageout	2019-11-15 18:33:59 -08:00
Makefile	mm: silence -Woverride-init/initializer-overrides	2019-09-24 15:54:10 -07:00
memblock.c	mm: memblock: do not enforce current limit for memblock_phys* family	2019-10-19 06:32:32 -04:00
memcontrol.c	mm: memcg: switch to css_tryget() in get_mem_cgroup_from_mm()	2019-11-15 18:34:00 -08:00
memfd.c	mm: page cache: store only head pages in i_pages	2019-09-24 15:54:08 -07:00
memory_hotplug.c	mm/memory_hotplug: fix updating the node span	2019-11-06 08:47:50 -08:00
memory-failure.c	mm/memory-failure.c: don't access uninitialized memmaps in memory_failure()	2019-10-19 06:32:31 -04:00
memory.c	mm: do not hash address in print_bad_pte()	2019-09-24 15:54:09 -07:00
mempolicy.c	mm: mempolicy: fix the wrong return value and potential pages leak of mbind	2019-11-15 18:33:59 -08:00
mempool.c	docs/core-api/mm: fix return value descriptions in mm/	2019-03-05 21:07:20 -08:00
memremap.c	mm/memunmap: don't access uninitialized memmap in memunmap_pages()	2019-10-19 06:32:32 -04:00
memtest.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
migrate.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
mincore.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
mlock.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
mm_init.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
mmap.c	mm: untag user pointers in mmap/munmap/mremap/brk	2019-09-25 17:51:41 -07:00
mmu_context.c
mmu_gather.c	mm: remove quicklist page table caches	2019-09-24 15:54:09 -07:00
mmu_notifier.c	mm/mmu_notifiers: use the right return code for WARN_ON	2019-11-06 08:47:50 -08:00
mmzone.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mprotect.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
mremap.c	mm: untag user pointers in mmap/munmap/mremap/brk	2019-09-25 17:51:41 -07:00
msync.c	mm: untag user pointers passed to memory syscalls	2019-09-25 17:51:41 -07:00
nommu.c	mm: introduce page_size()	2019-09-24 15:54:08 -07:00
oom_kill.c	mm: introduce MADV_COLD	2019-09-25 17:51:41 -07:00
page_alloc.c	mm/page_alloc.c: ratelimit allocation failure warnings more aggressively	2019-11-06 08:47:50 -08:00
page_counter.c	memcg: introduce memory.min	2018-06-07 17:34:36 -07:00
page_ext.c	mm, page_owner: fix off-by-one error in __set_page_owner_handle()	2019-10-14 15:04:00 -07:00
page_idle.c	mm/page_idle.c: fix oops because end_pfn is larger than max_pfn	2019-06-29 16:43:45 +08:00
page_io.c	mm, swap: use rbtree for swap_extent	2019-07-12 11:05:43 -07:00
page_isolation.c	mm/page_isolation.c: change the prototype of undo_isolate_page_range()	2019-07-12 11:05:43 -07:00
page_owner.c	mm/page_owner: don't access uninitialized memmaps when reading /proc/pagetypeinfo	2019-10-19 06:32:31 -04:00
page_poison.c	mm/page_poison.c: fix a typo in a comment	2019-09-24 15:54:08 -07:00
page_vma_mapped.c	mm: introduce page_size()	2019-09-24 15:54:08 -07:00
page-writeback.c	writeback, memcg: Implement foreign dirty flushing	2019-08-27 09:22:38 -06:00
pagewalk.c	pagewalk: use lockdep_assert_held for locking validation	2019-09-07 04:28:04 -03:00
percpu-internal.h	percpu: convert chunk hints to be based on pcpu_block_md	2019-03-13 12:25:31 -07:00
percpu-km.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu-stats.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu-vm.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428	2019-06-05 17:37:16 +02:00
percpu.c	percpu: Use struct_size() helper	2019-09-04 13:40:49 -07:00
pgtable-generic.c	x86/mm: Page size aware flush_tlb_mm_range()	2018-10-09 16:51:11 +02:00
process_vm_access.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
readahead.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
rmap.c	mm: include <linux/huge_mm.h> for is_vma_temporary_stack	2019-10-19 06:32:32 -04:00
rodata_test.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441	2019-06-05 17:37:17 +02:00
shmem.c	Merge branch 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-10-10 08:16:44 -07:00
shuffle.c	mm: fix -Wmissing-prototypes warnings	2019-10-07 15:47:19 -07:00
shuffle.h	mm: maintain randomization of page free lists	2019-05-14 19:52:48 -07:00
slab_common.c	mm: memcg/slab: fix panic in __free_slab() caused by premature memcg pointer release	2019-10-19 06:32:32 -04:00
slab.c	mm/slab.c: fix kernel-doc warning for __ksize()	2019-10-14 15:04:01 -07:00
slab.h	mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly	2019-11-06 08:47:50 -08:00
slob.c	mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two)	2019-10-07 15:47:20 -07:00
slub.c	mm/slub.c: init_on_free=1 should wipe freelist ptr for bulk allocations	2019-10-14 15:04:01 -07:00
sparse-vmemmap.c	mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()	2019-07-18 17:08:07 -07:00
sparse.c	mm: fix -Wmissing-prototypes warnings	2019-10-07 15:47:19 -07:00
swap_cgroup.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
swap_slots.c	mm, swap, get_swap_pages: use entry_size instead of cluster in parameter	2018-08-22 10:52:44 -07:00
swap_state.c	mm: page cache: store only head pages in i_pages	2019-09-24 15:54:08 -07:00
swap.c	mm: introduce MADV_COLD	2019-09-25 17:51:41 -07:00
swapfile.c	vfs: don't allow writes to swap files	2019-08-20 07:55:16 -07:00
truncate.c	mm/thp: allow dropping THP from page cache	2019-10-19 06:32:33 -04:00
usercopy.c	usercopy: Avoid HIGHMEM pfn warning	2019-09-17 15:20:17 -07:00
userfaultfd.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499	2019-06-19 17:09:53 +02:00
util.c	arm64, mm: make randomization selected by generic topdown mmap layout	2019-09-24 15:54:11 -07:00
vmacache.c	mm: get rid of vmacache_flush_all() entirely	2018-09-13 15:18:04 -10:00
vmalloc.c	augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro	2019-09-25 17:51:39 -07:00
vmpressure.c	mm/vmpressure.c: fix a signedness bug in vmpressure_register_event()	2019-10-07 15:47:19 -07:00
vmscan.c	mm/vmscan.c: support removing arbitrary sized pages from mapping	2019-10-19 06:32:32 -04:00
vmstat.c	mm, vmstat: reduce zone->lock holding time by /proc/pagetypeinfo	2019-11-06 08:47:50 -08:00
workingset.c	mm: workingset: fix vmstat counters for shadow nodes	2019-08-13 16:06:52 -07:00
z3fold.c	mm/z3fold.c: claim page in the beginning of free	2019-10-07 15:47:19 -07:00
zbud.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
zpool.c	zpool: add malloc_support_movable to zpool_driver	2019-09-24 15:54:12 -07:00
zsmalloc.c	mm/zsmalloc.c: fix a -Wunused-function warning	2019-09-24 15:54:12 -07:00
zswap.c	zswap: do not map same object twice	2019-09-24 15:54:12 -07:00