PM: hibernate: Replace deprecated kmap_atomic() with kmap_local_page()

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with H

PM: hibernate: Replace deprecated kmap_atomic() with kmap_local_page()

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can
take page faults, and allows preemption.

According to [2], this replacement is safe as long as the code between
kmap_atomic() and kunmap_atomic() does not implicitly depend on disabling
page faults or preemption. In all of the call sites in this patch, the only
thing happening between mapping and unmapping pages is copy_page() calls,
and I don't suspect they depend on disabling page faults or preemption.

Link: https://lwn.net/Articles/836144/ [1]
Link: https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings [2]
Signed-off-by: David Reaver <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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mm/memblock: add memblock_alloc_or_panic interface

Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory. In most cases, when memory allocation fails, an
immediate p

mm/memblock: add memblock_alloc_or_panic interface

Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory. In most cases, when memory allocation fails, an
immediate panic is required. To simplify this behavior and reduce
repetitive checks, introduce `memblock_alloc_or_panic`. This function
ensures that memory allocation failures result in a panic automatically,
improving code readability and consistency across subsystems that require
this behavior.

[[email protected]: arch/s390: save_area_alloc default failure behavior changed to panic]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Guo Weikang <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]> [m68k]
Reviewed-by: Alexander Gordeev <[email protected]> [s390]
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

PM: hibernate: Remove unused stub for saveable_highmem_page()

When saveable_highmem_page() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:

kernel/power/snapshot.c:1

PM: hibernate: Remove unused stub for saveable_highmem_page()

When saveable_highmem_page() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:

kernel/power/snapshot.c:1369:21: error: unused function 'saveable_highmem_page' [-Werror,-Wunused-function]
1369 | static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
| ^~~~~~~~~~~~~~~~~~~~~

Fix this by removing unused stub.

See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Don't ignore return from set_memory_ro()

set_memory_ro() and set_memory_rw() can fail, leaving memory
unprotected.

Take the returned value into account and abort in case of
failure.

PM: hibernate: Don't ignore return from set_memory_ro()

set_memory_ro() and set_memory_rw() can fail, leaving memory
unprotected.

Take the returned value into account and abort in case of
failure.

Signed-off-by: Christophe Leroy <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Use kmap_local_page() in copy_data_page()

kmap_atomic() has been deprecated in favor of kmap_local_page().

kmap_atomic() disables page-faults and preemption (the latter
only for !PRE

PM: hibernate: Use kmap_local_page() in copy_data_page()

kmap_atomic() has been deprecated in favor of kmap_local_page().

kmap_atomic() disables page-faults and preemption (the latter
only for !PREEMPT_RT kernels).The code between the mapping and
un-mapping in this patch does not depend on the above-mentioned
side effects.So simply replaced kmap_atomic() with kmap_local_page().

Signed-off-by: Chen Haonan <[email protected]>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Do not initialize error in snapshot_write_next()

The error variable in snapshot_write_next() gets a value before it is
used, so don't initialize it to 0 upfront.

Signed-off-by: Li ze

PM: hibernate: Do not initialize error in snapshot_write_next()

The error variable in snapshot_write_next() gets a value before it is
used, so don't initialize it to 0 upfront.

Signed-off-by: Li zeming <[email protected]>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Drop unnecessary local variable initialization

It is not necessary to intialize the error variable in
create_basic_memory_bitmaps(), because it is only read after
being assigned a val

PM: hibernate: Drop unnecessary local variable initialization

It is not necessary to intialize the error variable in
create_basic_memory_bitmaps(), because it is only read after
being assigned a value.

Signed-off-by: Wang chaodong <[email protected]>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Fix copying the zero bitmap to safe pages

The following crash is observed 100% of the time during resume from
the hibernation on a x86 QEMU system.

[ 12.931887] ? __die_body+0x1a/

PM: hibernate: Fix copying the zero bitmap to safe pages

The following crash is observed 100% of the time during resume from
the hibernation on a x86 QEMU system.

[ 12.931887] ? __die_body+0x1a/0x60
[ 12.932324] ? page_fault_oops+0x156/0x420
[ 12.932824] ? search_exception_tables+0x37/0x50
[ 12.933389] ? fixup_exception+0x21/0x300
[ 12.933889] ? exc_page_fault+0x69/0x150
[ 12.934371] ? asm_exc_page_fault+0x26/0x30
[ 12.934869] ? get_buffer.constprop.0+0xac/0x100
[ 12.935428] snapshot_write_next+0x7c/0x9f0
[ 12.935929] ? submit_bio_noacct_nocheck+0x2c2/0x370
[ 12.936530] ? submit_bio_noacct+0x44/0x2c0
[ 12.937035] ? hib_submit_io+0xa5/0x110
[ 12.937501] load_image+0x83/0x1a0
[ 12.937919] swsusp_read+0x17f/0x1d0
[ 12.938355] ? create_basic_memory_bitmaps+0x1b7/0x240
[ 12.938967] load_image_and_restore+0x45/0xc0
[ 12.939494] software_resume+0x13c/0x180
[ 12.939994] resume_store+0xa3/0x1d0

The commit being fixed introduced a bug in copying the zero bitmap
to safe pages. A temporary bitmap is allocated with PG_ANY flag in
prepare_image() to make a copy of zero bitmap after the unsafe pages
are marked. Freeing this temporary bitmap with PG_UNSAFE_KEEP later
results in an inconsistent state of unsafe pages. Since free bit is
left as is for this temporary bitmap after free, these pages are
treated as unsafe pages when they are allocated again. This results
in incorrect calculation of the number of pages pre-allocated for the
image.

nr_pages = (nr_zero_pages + nr_copy_pages) - nr_highmem - allocated_unsafe_pages;

The allocate_unsafe_pages is estimated to be higher than the actual
which results in running short of pages in safe_pages_list. Hence the
crash is observed in get_buffer() due to NULL pointer access of
safe_pages_list.

Fix this issue by creating the temporary zero bitmap from safe pages
(free bit not set) so that the corresponding free bits can be cleared
while freeing this bitmap.

Fixes: 005e8dddd497 ("PM: hibernate: don't store zero pages in the image file")
Suggested-by:: Brian Geffon <[email protected]>
Signed-off-by: Pavankumar Kondeti <[email protected]>
Reviewed-by: Brian Geffon <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Clean up sync_read handling in snapshot_write_next()

In snapshot_write_next(), sync_read is set and unset in three different
spots unnecessiarly. As a result there is a subtle bug whe

PM: hibernate: Clean up sync_read handling in snapshot_write_next()

In snapshot_write_next(), sync_read is set and unset in three different
spots unnecessiarly. As a result there is a subtle bug where the first
page after the meta data has been loaded unconditionally sets sync_read
to 0. If this first PFN was actually a highmem page, then the returned
buffer will be the global "buffer," and the page needs to be loaded
synchronously.

That is, I'm not sure we can always assume the following to be safe:

handle->buffer = get_buffer(&orig_bm, &ca);
handle->sync_read = 0;

Because get_buffer() can call get_highmem_page_buffer() which can
return 'buffer'.

The easiest way to address this is just set sync_read before
snapshot_write_next() returns if handle->buffer == buffer.

Signed-off-by: Brian Geffon <[email protected]>
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable <[email protected]>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: hibernate: Use __get_safe_page() rather than touching the list

We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.

Signe

PM: hibernate: Use __get_safe_page() rather than touching the list

We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.

Signed-off-by: Brian Geffon <[email protected]>
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: don't store zero pages in the image file

On ChromeOS we've observed a considerable number of in-use pages filled with
zeros. Today with hibernate it's entirely possible that saveable

PM: hibernate: don't store zero pages in the image file

On ChromeOS we've observed a considerable number of in-use pages filled with
zeros. Today with hibernate it's entirely possible that saveable pages are just
zero filled. Since we're already copying pages word-by-word in do_copy_page it
becomes almost free to determine if a page was completely filled with zeros.

This change introduces a new bitmap which will track these zero pages. If a page
is zero it will not be included in the saved image, instead to track these zero
pages in the image file we will introduce a new flag which we will set on the
packed PFN list. When reading back in the image file we will detect these zero
page PFNs and rebuild the zero page bitmap.

When the image is being loaded through calls to write_next_page if we encounter
a zero page we will silently memset it to 0 and then continue on to the next
page. Given the implementation in snapshot_read_next/snapshot_write_next this
change will be transparent to non-compressed/compressed and swsusp modes of
operation.

To provide some concrete numbers from simple ad-hoc testing, on a device which
was lightly in use we saw that:

PM: hibernation: Image created (964408 pages copied, 548304 zero pages)

Of the approximately 6.2GB of saveable pages 2.2GB (36%) were just zero filled
and could be tracked entirely within the packed PFN list. The savings would
obviously be much lower for lzo compressed images, but even in the case of
compression not copying pages across to the compression threads will still
speed things up. It's also possible that we would see better overall compression
ratios as larger regions of "real data" would improve the compressibility.

Finally, such an approach could dramatically improve swsusp performance
as each one of those zero pages requires a write syscall to reload, by
handling it as part of the packed PFN list we're able to fully avoid
that.

Signed-off-by: Brian Geffon <[email protected]>
[ rjw: Whitespace adjustments, removal of redundant parentheses ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

mm: page_alloc: move mark_free_page() into snapshot.c

The mark_free_page() is only used in kernel/power/snapshot.c, move it out
to reduce a bit of page_alloc.c

Link: https://lkml.kernel.org/r/20230

mm: page_alloc: move mark_free_page() into snapshot.c

The mark_free_page() is only used in kernel/power/snapshot.c, move it out
to reduce a bit of page_alloc.c

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Iurii Zaikin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

show more ...

PM: hibernate: Correct spelling mistake in a comment

Fix a typo in a comment in kernel/power/snapshot.c

Signed-off-by: Wang Honghui <[email protected]>
[ rjw: Subject and changelog edits ]
S

PM: hibernate: Correct spelling mistake in a comment

Fix a typo in a comment in kernel/power/snapshot.c

Signed-off-by: Wang Honghui <[email protected]>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Complain about memory map mismatches during resume

The system memory map can change over a hibernation-restore cycle due
to a defect in the platform firmware, and some of the page fra

PM: hibernate: Complain about memory map mismatches during resume

The system memory map can change over a hibernation-restore cycle due
to a defect in the platform firmware, and some of the page frames used
by the kernel before hibernation may not be available any more during
the subsequent restore which leads to the error below.

[ T357] PM: Image loading progress: 0%
[ T357] PM: Read 2681596 kbytes in 0.03 seconds (89386.53 MB/s)
[ T357] PM: Error -14 resuming
[ T357] PM: Failed to load hibernation image, recovering.
[ T357] PM: Basic memory bitmaps freed
[ T357] OOM killer enabled.
[ T357] Restarting tasks ... done.
[ T357] PM: resume from hibernation failed (-14)
[ T357] PM: Hibernation image not present or could not be loaded.

Add an error message to the unpack() function to allow problematic
page frames to be identified and the source of the problem to be
diagnosed more easily. This can save developers quite a bit of
debugging time.

Signed-off-by: Xueqin Luo <[email protected]>
[ rjw: New subject, edited changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Fix mistake in kerneldoc comment

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
- 2 * DIV_

PM: hibernate: Fix mistake in kerneldoc comment

The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:

max_size = (count - (size + PAGES_FOR_IO)) / 2
- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);

but the one in the kerneldoc comment of the function is different and
incorrect.

Fixes: ddeb64870810 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin <[email protected]>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Don't mark comment as kernel-doc

Change the comment to a normal (non-kernel-doc) comment to avoid
these kernel-doc warnings:

kernel/power/snapshot.c:335: warning: This comment starts

PM: hibernate: Don't mark comment as kernel-doc

Change the comment to a normal (non-kernel-doc) comment to avoid
these kernel-doc warnings:

kernel/power/snapshot.c:335: warning: This comment starts with '/**', but
isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Data types related to memory bitmaps.

Signed-off-by: Haowen Bai <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Fix some kernel-doc comments

Add parameter description in alloc_rtree_node() kernel-doc
comment and fix several inconsistent function name descriptions.

Remove some warnings found b

PM: hibernate: Fix some kernel-doc comments

Add parameter description in alloc_rtree_node() kernel-doc
comment and fix several inconsistent function name descriptions.

Remove some warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.

kernel/power/snapshot.c:438: warning: Function parameter or member
'gfp_mask' not described in 'alloc_rtree_node'
kernel/power/snapshot.c:438: warning: Function parameter or member
'safe_needed' not described in 'alloc_rtree_node'
kernel/power/snapshot.c:438: warning: Function parameter or member 'ca'
not described in 'alloc_rtree_node'
kernel/power/snapshot.c:438: warning: Function parameter or member
'list' not described in 'alloc_rtree_node'
kernel/power/snapshot.c:916: warning: expecting prototype for
memory_bm_rtree_next_pfn(). Prototype was for memory_bm_next_pfn()
instead
kernel/power/snapshot.c:1947: warning: expecting prototype for
alloc_highmem_image_pages(). Prototype was for alloc_highmem_pages()
instead
kernel/power/snapshot.c:2230: warning: expecting prototype for load
header(). Prototype was for load_header() instead

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
[ rjw: Comment adjustments to avoid line breaks ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: Remove register_nosave_region_late()

It is an unused wrapper forcing kmalloc allocation for registering
nosave regions. Also, rename __register_nosave_region() to
register_nosave_regi

PM: hibernate: Remove register_nosave_region_late()

It is an unused wrapper forcing kmalloc allocation for registering
nosave regions. Also, rename __register_nosave_region() to
register_nosave_region() now that there is no need for disambiguation.

Signed-off-by: Amadeusz Sławiński <[email protected]>
Reviewed-by: Cezary Rojewski <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: remove leading spaces before tabs

1) Run the following command to find and remove the leading spaces
before tabs:
$ find kernel/power/ -type f | xargs sed -r -i 's/^[ ]+\t/\t

PM: hibernate: remove leading spaces before tabs

1) Run the following command to find and remove the leading spaces
before tabs:
$ find kernel/power/ -type f | xargs sed -r -i 's/^[ ]+\t/\t/'
2) Manually check and correct if necessary

Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: hibernate: fix spelling mistakes

Fix some spelling mistakes in comments:

corresonds ==> corresponds
alocated ==> allocated
unitialized ==> uninitialized
Deompression ==> Decompression

Signed-o

PM: hibernate: fix spelling mistakes

Fix some spelling mistakes in comments:

corresonds ==> corresponds
alocated ==> allocated
unitialized ==> uninitialized
Deompression ==> Decompression

Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

show more ...

PM: sleep: fix typos in comments

Change "occured" to "occurred" in kernel/power/autosleep.c.

Change "consiting" to "consisting" in kernel/power/snapshot.c.

Change "avaiable" to "available" in kern

PM: sleep: fix typos in comments

Change "occured" to "occurred" in kernel/power/autosleep.c.

Change "consiting" to "consisting" in kernel/power/snapshot.c.

Change "avaiable" to "available" in kernel/power/swap.c.

No functionality changed.

Signed-off-by: Lu Jialin <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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kernel/power: allow hibernation with page_poison sanity checking

Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_H

kernel/power: allow hibernation with page_poison sanity checking

Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY. For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation. The latter restriction was removed by commit 1ad1410f632d
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f9e58 ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.

We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume. This covers both zero and 0xAA patterns. Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]> [hibernation]
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Laura Abbott <[email protected]>
Cc: Mateusz Nosek <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

PM: hibernate: make direct map manipulations more explicit

When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be
not present in the direct map and has to be explicitly mapped befo

PM: hibernate: make direct map manipulations more explicit

When DEBUG_PAGEALLOC or ARCH_HAS_SET_DIRECT_MAP is enabled a page may be
not present in the direct map and has to be explicitly mapped before it
could be copied.

Introduce hibernate_map_page() and hibernation_unmap_page() that will
explicitly use set_direct_map_{default,invalid}_noflush() for
ARCH_HAS_SET_DIRECT_MAP case and debug_pagealloc_{map,unmap}_pages() for
DEBUG_PAGEALLOC case.

The remapping of the pages in safe_copy_page() presumes that it only
changes protection bits in an existing PTE and so it is safe to ignore
return value of set_direct_map_{default,invalid}_noflush().

Still, add a pr_warn() so that future changes in set_memory APIs will not
silently break hibernation.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mike Rapoport <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: "Edgecombe, Rick P" <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kernel/: fix repeated words in comments

Fix multiple occurrences of duplicated words in kernel/.

Fix one typo/spello on the same line as a duplicate word. Change one
instance of "the the" to "that

kernel/: fix repeated words in comments

Fix multiple occurrences of duplicated words in kernel/.

Fix one typo/spello on the same line as a duplicate word. Change one
instance of "the the" to "that the". Otherwise just drop one of the
repeated words.

Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

mm: memcg: convert vmstat slab counters to bytes

In order to prepare for per-object slab memory accounting, convert
NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes.

To make it o

mm: memcg: convert vmstat slab counters to bytes

In order to prepare for per-object slab memory accounting, convert
NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE vmstat items to bytes.

To make it obvious, rename them to NR_SLAB_RECLAIMABLE_B and
NR_SLAB_UNRECLAIMABLE_B (similar to NR_KERNEL_STACK_KB).

Internally global and per-node counters are stored in pages, however memcg
and lruvec counters are stored in bytes. This scheme may look weird, but
only for now. As soon as slab pages will be shared between multiple
cgroups, global and node counters will reflect the total number of slab
pages. However memcg and lruvec counters will be used for per-memcg slab
memory tracking, which will take separate kernel objects in the account.
Keeping global and node counters in pages helps to avoid additional
overhead.

The size of slab memory shouldn't exceed 4Gb on 32-bit machines, so it
will fit into atomic_long_t we use for vmstats.

Signed-off-by: Roman Gushchin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Tejun Heo <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

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