linux-stable.git/mm/percpu.c, branch v6.2.1

mm/percpu.c: remove the lcm code since block size is fixed at page size

2022-11-08T06:59:18+00:00

Since commit b239f7daf553 ("percpu: set PCPU_BITMAP_BLOCK_SIZE to
PAGE_SIZE"), the PCPU_BITMAP_BLOCK_SIZE has been set to page size
fixedly. So the lcm code in pcpu_alloc_first_chunk() doesn't make
sense any more, clean it up.

Signed-off-by: Baoquan He 
Signed-off-by: Dennis Zhou

mm/percpu: replace the goto with break

2022-11-08T06:59:15+00:00

In function pcpu_reclaim_populated(), the line of goto jumping is
unnecessary since the label 'end_chunk' is near the end of the for
loop, use break instead.

Signed-off-by: Baoquan He 
Signed-off-by: Dennis Zhou

mm/percpu: add comment to state the empty populated pages accounting

2022-11-08T06:59:12+00:00

When allocating an area from a chunk, pcpu_block_update_hint_alloc()
is called to update chunk metadata, including chunk's and global
nr_empty_pop_pages. However, if the allocation is not atomic, some
blocks may not be populated with pages yet, while we still subtract
the number here. The number of pages will be added back with
pcpu_chunk_populated() when populating pages.

Adding code comment to make that more understandable.

Signed-off-by: Baoquan He 
Signed-off-by: Dennis Zhou

mm/percpu: Update the code comment when creating new chunk

2022-11-08T06:59:06+00:00

The lock pcpu_alloc_mutex taking code has been moved to the beginning of
pcpu_allo() if it's non atomic allocation. So the code comment above
above pcpu_create_chunk() callsite need be updated.

Signed-off-by: Baoquan He 
Signed-off-by: Dennis Zhou

mm/percpu: use list_first_entry_or_null in pcpu_reclaim_populated()

2022-11-08T06:57:53+00:00

To replace list_empty()/list_first_entry() pair to simplify code.

Signed-off-by: Baoquan He 
Acked-by: Dennis Zhou 
Signed-off-by: Dennis Zhou

mm/percpu: remove unused pcpu_map_extend_chunks

2022-11-08T06:57:32+00:00

Since commit 40064aeca35c ("percpu: replace area map allocator with
bitmap"), it is unneeded.

Signed-off-by: Baoquan He 
Signed-off-by: Dennis Zhou

mm: percpu: use kmemleak_ignore_phys() instead of kmemleak_free()

2022-07-18T00:14:47+00:00

Kmemleak recently added a rbtree to store the objects allocted with
physical address.  Those objects can't be freed with kmemleak_free().

According to the comments, percpu allocations are tracked by kmemleak
separately.  Kmemleak_free() was used to avoid the unnecessary
tracking.  If kmemleak_free() fails, those objects would be scanned by
kmemleak, which is unnecessary but shouldn't lead to other effects.

Use kmemleak_ignore_phys() instead of kmemleak_free() for those
objects.

Link: https://lkml.kernel.org/r/20220705113158.127600-1-patrick.wang.shcn@gmail.com
Fixes: 0c24e061196c ("mm: kmemleak: add rbtree and store physical address for objects allocated with PA")
Signed-off-by: Patrick Wang 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Catalin Marinas 
Signed-off-by: Andrew Morton

percpu: improve percpu_alloc_percpu event trace

2022-05-13T14:20:18+00:00

Add call_site, bytes_alloc and gfp_flags fields to the output of the
percpu_alloc_percpu ftrace event:

mkdir-4393  [001]   169.334788: percpu_alloc_percpu:
 call_site=mem_cgroup_css_alloc+0xa6 reserved=0 is_atomic=0 size=2408 align=8
  base_addr=0xffffc7117fc00000 off=402176 ptr=0x3dc867a62300 bytes_alloc=14448
   gfp_flags=GFP_KERNEL_ACCOUNT

This is required to track memcg-accounted percpu allocations.

Link: https://lkml.kernel.org/r/a07be858-c8a3-7851-9086-e3262cbcf707@openvz.org
Signed-off-by: Vasily Averin 
Acked-by: Roman Gushchin 
Cc: Shakeel Butt 
Cc: Steven Rostedt 
Cc: Ingo Molnar 
Cc: Vlastimil Babka 
Cc: Michal Hocko 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton

Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux

2022-01-23T04:20:44+00:00

Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly

Merge branch 'akpm' (patches from Andrew)

2022-01-20T08:41:01+00:00

Merge more updates from Andrew Morton:
 "55 patches.

  Subsystems affected by this patch series: percpu, procfs, sysctl,
  misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2,
  hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan"

* emailed patches from Andrew Morton : (55 commits)
  lib: remove redundant assignment to variable ret
  ubsan: remove CONFIG_UBSAN_OBJECT_SIZE
  kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
  lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB
  btrfs: use generic Kconfig option for 256kB page size limit
  arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB
  configs: introduce debug.config for CI-like setup
  delayacct: track delays from memory compact
  Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact
  delayacct: cleanup flags in struct task_delay_info and functions use it
  delayacct: fix incomplete disable operation when switch enable to disable
  delayacct: support swapin delay accounting for swapping without blkio
  panic: remove oops_id
  panic: use error_report_end tracepoint on warnings
  fs/adfs: remove unneeded variable make code cleaner
  FAT: use io_schedule_timeout() instead of congestion_wait()
  hfsplus: use struct_group_attr() for memcpy() region
  nilfs2: remove redundant pointer sbufs
  fs/binfmt_elf: use PT_LOAD p_align values for static PIE
  const_structs.checkpatch: add frequently used ops structs
  ...