linux/fs/proc
Ryan Roberts 3485b88390 mm: thp: introduce multi-size THP sysfs interface
In preparation for adding support for anonymous multi-size THP, introduce
new sysfs structure that will be used to control the new behaviours.  A
new directory is added under transparent_hugepage for each supported THP
size, and contains an `enabled` file, which can be set to "inherit" (to
inherit the global setting), "always", "madvise" or "never".  For now, the
kernel still only supports PMD-sized anonymous THP, so only 1 directory is
populated.

The first half of the change converts transhuge_vma_suitable() and
hugepage_vma_check() so that they take a bitfield of orders for which the
user wants to determine support, and the functions filter out all the
orders that can't be supported, given the current sysfs configuration and
the VMA dimensions.  The resulting functions are renamed to
thp_vma_suitable_orders() and thp_vma_allowable_orders() respectively. 
Convenience functions that take a single, unencoded order and return a
boolean are also defined as thp_vma_suitable_order() and
thp_vma_allowable_order().

The second half of the change implements the new sysfs interface.  It has
been done so that each supported THP size has a `struct thpsize`, which
describes the relevant metadata and is itself a kobject.  This is pretty
minimal for now, but should make it easy to add new per-thpsize files to
the interface if needed in future (e.g.  per-size defrag).  Rather than
keep the `enabled` state directly in the struct thpsize, I've elected to
directly encode it into huge_anon_orders_[always|madvise|inherit]
bitfields since this reduces the amount of work required in
thp_vma_allowable_orders() which is called for every page fault.

See Documentation/admin-guide/mm/transhuge.rst, as modified by this
commit, for details of how the new sysfs interface works.

[ryan.roberts@arm.com: fix build warning when CONFIG_SYSFS is disabled]
  Link: https://lkml.kernel.org/r/20231211125320.3997543-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20231207161211.2374093-4-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Barry Song <v-songbaohua@oppo.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 14:48:12 -08:00
..
array.c fs/proc: do_task_stat: use __for_each_thread() 2023-10-04 10:41:57 -07:00
base.c As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
bootconfig.c fs/proc: Add boot loader arguments as comment to /proc/bootconfig 2023-10-07 10:45:56 +09:00
cmdline.c proc: mark /proc/cmdline as permanent 2023-02-02 22:50:02 -08:00
consoles.c proc: consoles: use console_list_lock for list iteration 2022-12-02 11:25:02 +01:00
cpuinfo.c x86/aperfmperf: Replace aperfmperf_get_khz() 2022-04-27 20:22:19 +02:00
devices.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
fd.c file: convert to SLAB_TYPESAFE_BY_RCU 2023-10-19 11:02:48 +02:00
fd.h fs: port ->permission() to pass mnt_idmap 2023-01-19 09:24:28 +01:00
generic.c fs: pass the request_mask to generic_fillattr 2023-08-09 08:56:36 +02:00
inode.c As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
internal.h proc: nommu: fix empty /proc/<pid>/maps 2023-09-19 13:21:34 -07:00
interrupts.c
Kconfig proc: make config PROC_CHILDREN depend on PROC_FS 2022-10-03 14:21:43 -07:00
kcore.c proc/kcore: do not try to access unaccepted memory 2023-10-04 10:32:22 -07:00
kmsg.c printk changes for 6.1 2022-10-10 11:24:19 -07:00
loadavg.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
Makefile proc: bootconfig: Add /proc/bootconfig to show boot config list 2020-01-13 13:19:39 -05:00
meminfo.c mm: memtest: convert to memtest_report_meminfo() 2023-08-21 13:37:47 -07:00
namespaces.c Merge branch 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-01-29 11:20:24 -08:00
nommu.c fs: create helper file_user_path() for user displayed mapped file path 2023-10-19 11:03:15 +02:00
page.c mm, pagemap: remove SLOB and SLQB from comments and documentation 2023-03-29 10:32:11 +02:00
proc_net.c v6.6-fs.proc.uapi 2023-08-28 11:43:19 -07:00
proc_sysctl.c sysctl-6.7-rc1 2023-11-01 20:51:41 -10:00
proc_tty.c proc: delete unused <linux/uaccess.h> includes 2022-07-17 17:31:39 -07:00
root.c fs: super: dynamically allocate the s_shrink 2023-10-04 10:32:26 -07:00
self.c proc: convert to new timestamp accessors 2023-10-18 14:08:26 +02:00
softirqs.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
stat.c proc/stat: remove arch_idle_time() 2023-04-18 16:39:33 -07:00
task_mmu.c mm: thp: introduce multi-size THP sysfs interface 2023-12-20 14:48:12 -08:00
task_nommu.c vfs-6.7.misc 2023-10-30 09:14:19 -10:00
thread_self.c proc: convert to new timestamp accessors 2023-10-18 14:08:26 +02:00
uptime.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
util.c
version.c proc: mark more files as permanent 2022-10-03 14:21:45 -07:00
vmcore.c proc/vmcore: fix signedness bug in read_from_oldmem() 2023-07-27 13:07:05 -07:00