linux-stable.git/lib/Kconfig, branch v6.14.2 Linux kernel stable tree lib/crc32: remove other generic implementations 2025-01-29T17:10:35+00:00 Eric Biggers ebiggers@google.com 2025-01-23T21:29:04+00:00 5e3c1c48fac3793c173567df735890d4e29cbb64 Now that we've standardized on the byte-by-byte implementation of CRC32 as the only generic implementation (see previous commit for the rationale), remove the code for the other implementations. Tested with crc_kunit. Link: https://lore.kernel.org/r/20250123212904.118683-3-ebiggers@kernel.org Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Eric Biggers <ebiggers@google.com> 
Now that we've standardized on the byte-by-byte implementation of CRC32
as the only generic implementation (see previous commit for the
rationale), remove the code for the other implementations.

Tested with crc_kunit.

Link: https://lore.kernel.org/r/20250123212904.118683-3-ebiggers@kernel.org
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc: simplify the kconfig options for CRC implementations 2025-01-29T17:10:32+00:00 Eric Biggers ebiggers@google.com 2025-01-23T21:29:03+00:00 b0430f39de089920e3aab3f4a9c35c35110bdbea Make the following simplifications to the kconfig options for choosing CRC implementations for CRC32 and CRC_T10DIF: 1. Make the option to disable the arch-optimized code be visible only when CONFIG_EXPERT=y. 2. Make a single option control the inclusion of the arch-optimized code for all enabled CRC variants. 3. Make CRC32_SARWATE (a.k.a. slice-by-1 or byte-by-byte) be the only generic CRC32 implementation. The result is there is now just one option, CRC_OPTIMIZATIONS, which is default y and can be disabled only when CONFIG_EXPERT=y. Rationale: 1. Enabling the arch-optimized code is nearly always the right choice. However, people trying to build the tiniest kernel possible would find some use in disabling it. Anything we add to CRC32 is de facto unconditional, given that CRC32 gets selected by something in nearly all kernels. And unfortunately enabling the arch CRC code does not eliminate the need to build the generic CRC code into the kernel too, due to CPU feature dependencies. The size of the arch CRC code will also increase slightly over time as more CRC variants get added and more implementations targeting different instruction set extensions get added. Thus, it seems worthwhile to still provide an option to disable it, but it should be considered an expert-level tweak. 2. Considering the use case described in (1), there doesn't seem to be sufficient value in making the arch-optimized CRC code be independently configurable for different CRC variants. Note also that multiple variants were already grouped together, e.g. CONFIG_CRC32 actually enables three different variants of CRC32. 3. The bit-by-bit implementation is uselessly slow, whereas slice-by-n for n=4 and n=8 use tables that are inconveniently large: 4096 bytes and 8192 bytes respectively, compared to 1024 bytes for n=1. Higher n gives higher instruction-level parallelism, so higher n easily wins on traditional microbenchmarks on most CPUs. However, the larger tables, which are accessed randomly, can be harmful in real-world situations where the dcache may be cold or useful data may need be evicted from the dcache. Meanwhile, today most architectures have much faster CRC32 implementations using dedicated CRC32 instructions or carryless multiplication instructions anyway, which make the generic code obsolete in most cases especially on long messages. Another reason for going with n=1 is that this is already what is used by all the other CRC variants in the kernel. CRC32 was unique in having support for larger tables. But as per the above this can be considered an outdated optimization. The standardization on slice-by-1 a.k.a. CRC32_SARWATE makes much of the code in lib/crc32.c unused. A later patch will clean that up. Link: https://lore.kernel.org/r/20250123212904.118683-2-ebiggers@kernel.org Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Eric Biggers <ebiggers@google.com> 
Make the following simplifications to the kconfig options for choosing
CRC implementations for CRC32 and CRC_T10DIF:

1. Make the option to disable the arch-optimized code be visible only
   when CONFIG_EXPERT=y.
2. Make a single option control the inclusion of the arch-optimized code
   for all enabled CRC variants.
3. Make CRC32_SARWATE (a.k.a. slice-by-1 or byte-by-byte) be the only
   generic CRC32 implementation.

The result is there is now just one option, CRC_OPTIMIZATIONS, which is
default y and can be disabled only when CONFIG_EXPERT=y.

Rationale:

1. Enabling the arch-optimized code is nearly always the right choice.
   However, people trying to build the tiniest kernel possible would
   find some use in disabling it.  Anything we add to CRC32 is de facto
   unconditional, given that CRC32 gets selected by something in nearly
   all kernels.  And unfortunately enabling the arch CRC code does not
   eliminate the need to build the generic CRC code into the kernel too,
   due to CPU feature dependencies.  The size of the arch CRC code will
   also increase slightly over time as more CRC variants get added and
   more implementations targeting different instruction set extensions
   get added.  Thus, it seems worthwhile to still provide an option to
   disable it, but it should be considered an expert-level tweak.

2. Considering the use case described in (1), there doesn't seem to be
   sufficient value in making the arch-optimized CRC code be
   independently configurable for different CRC variants.  Note also
   that multiple variants were already grouped together, e.g.
   CONFIG_CRC32 actually enables three different variants of CRC32.

3. The bit-by-bit implementation is uselessly slow, whereas slice-by-n
   for n=4 and n=8 use tables that are inconveniently large: 4096 bytes
   and 8192 bytes respectively, compared to 1024 bytes for n=1.  Higher
   n gives higher instruction-level parallelism, so higher n easily wins
   on traditional microbenchmarks on most CPUs.  However, the larger
   tables, which are accessed randomly, can be harmful in real-world
   situations where the dcache may be cold or useful data may need be
   evicted from the dcache.  Meanwhile, today most architectures have
   much faster CRC32 implementations using dedicated CRC32 instructions
   or carryless multiplication instructions anyway, which make the
   generic code obsolete in most cases especially on long messages.

   Another reason for going with n=1 is that this is already what is
   used by all the other CRC variants in the kernel.  CRC32 was unique
   in having support for larger tables.  But as per the above this can
   be considered an outdated optimization.

   The standardization on slice-by-1 a.k.a. CRC32_SARWATE makes much of
   the code in lib/crc32.c unused.  A later patch will clean that up.

Link: https://lore.kernel.org/r/20250123212904.118683-2-ebiggers@kernel.org
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc32test: delete obsolete crc32test.c 2024-12-10T06:09:37+00:00 Eric Biggers ebiggers@google.com 2024-12-02T01:20:54+00:00 87fe0a131001ebadda9970c6341cc05c5e417506 Delete crc32test.c, since it has been superseded by crc_kunit.c. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Cc: Vinicius Peixoto <vpeixoto@lkcamp.dev> Link: https://lore.kernel.org/r/20241202012056.209768-11-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Delete crc32test.c, since it has been superseded by crc_kunit.c.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Cc: Vinicius Peixoto <vpeixoto@lkcamp.dev>
Link: https://lore.kernel.org/r/20241202012056.209768-11-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc-t10dif: add support for arch overrides 2024-12-02T01:23:13+00:00 Eric Biggers ebiggers@google.com 2024-12-02T01:20:46+00:00 0961c3bcefa64d5f0999e2b703391862c733bb52 Following what was done for CRC32, add support for architecture-specific override of the CRC-T10DIF library. This will allow the CRC-T10DIF library functions to access architecture-optimized code directly. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241202012056.209768-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Following what was done for CRC32, add support for architecture-specific
override of the CRC-T10DIF library.  This will allow the CRC-T10DIF
library functions to access architecture-optimized code directly.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc-t10dif: stop wrapping the crypto API 2024-12-02T01:23:13+00:00 Eric Biggers ebiggers@google.com 2024-12-02T01:20:45+00:00 be3c45b070cba3be4dd248b38d4798e3e2859451 In preparation for making the CRC-T10DIF library directly optimized for each architecture, like what has been done for CRC32, get rid of the weird layering where crc_t10dif_update() calls into the crypto API. Instead, move crc_t10dif_generic() into the crc-t10dif library module, and make crc_t10dif_update() just call crc_t10dif_generic(). Acceleration will be reintroduced via crc_t10dif_arch() in the following patches. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20241202012056.209768-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
In preparation for making the CRC-T10DIF library directly optimized for
each architecture, like what has been done for CRC32, get rid of the
weird layering where crc_t10dif_update() calls into the crypto API.
Instead, move crc_t10dif_generic() into the crc-t10dif library module,
and make crc_t10dif_update() just call crc_t10dif_generic().
Acceleration will be reintroduced via crc_t10dif_arch() in the following
patches.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20241202012056.209768-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc32: make crc32c() go directly to lib 2024-12-02T01:23:02+00:00 Eric Biggers ebiggers@google.com 2024-12-02T01:08:40+00:00 38a9a5121c3bcf2ed857430a92e493568b247c35 Now that the lower level __crc32c_le() library function is optimized for each architecture, make crc32c() just call that instead of taking an inefficient and error-prone detour through the shash API. Note: a future cleanup should make crc32c_le() be the actual library function instead of __crc32c_le(). That will require updating callers of __crc32c_le() to use crc32c_le() instead, and updating callers of crc32c_le() that expect a 'const void *' arg to expect 'const u8 *' instead. Similarly, a future cleanup should remove LIBCRC32C by making everyone who is selecting it just select CRC32 directly instead. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20241202010844.144356-16-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Now that the lower level __crc32c_le() library function is optimized for
each architecture, make crc32c() just call that instead of taking an
inefficient and error-prone detour through the shash API.

Note: a future cleanup should make crc32c_le() be the actual library
function instead of __crc32c_le().  That will require updating callers
of __crc32c_le() to use crc32c_le() instead, and updating callers of
crc32c_le() that expect a 'const void *' arg to expect 'const u8 *'
instead.  Similarly, a future cleanup should remove LIBCRC32C by making
everyone who is selecting it just select CRC32 directly instead.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-16-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
lib/crc32: improve support for arch-specific overrides 2024-12-02T01:23:01+00:00 Eric Biggers ebiggers@google.com 2024-12-02T01:08:27+00:00 d36cebe03c3ae4ea1fde20cfc797fab8729c3ab5 Currently the CRC32 library functions are defined as weak symbols, and the arm64 and riscv architectures override them. This method of arch-specific overrides has the limitation that it only works when both the base and arch code is built-in. Also, it makes the arch-specific code be silently not used if it is accidentally built with lib-y instead of obj-y; unfortunately the RISC-V code does this. This commit reorganizes the code to have explicit *_arch() functions that are called when they are enabled, similar to how some of the crypto library code works (e.g. chacha_crypt() calls chacha_crypt_arch()). Make the existing kconfig choice for the CRC32 implementation also control whether the arch-optimized implementation (if one is available) is enabled or not. Make it enabled by default if CRC32 is also enabled. The result is that arch-optimized CRC32 library functions will be included automatically when appropriate, but it is now possible to disable them. They can also now be built as a loadable module if the CRC32 library functions happen to be used only by loadable modules, in which case the arch and base CRC32 modules will be automatically loaded via direct symbol dependency when appropriate. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20241202010844.144356-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Currently the CRC32 library functions are defined as weak symbols, and
the arm64 and riscv architectures override them.

This method of arch-specific overrides has the limitation that it only
works when both the base and arch code is built-in.  Also, it makes the
arch-specific code be silently not used if it is accidentally built with
lib-y instead of obj-y; unfortunately the RISC-V code does this.

This commit reorganizes the code to have explicit *_arch() functions
that are called when they are enabled, similar to how some of the crypto
library code works (e.g. chacha_crypt() calls chacha_crypt_arch()).

Make the existing kconfig choice for the CRC32 implementation also
control whether the arch-optimized implementation (if one is available)
is enabled or not.  Make it enabled by default if CRC32 is also enabled.

The result is that arch-optimized CRC32 library functions will be
included automatically when appropriate, but it is now possible to
disable them.  They can also now be built as a loadable module if the
CRC32 library functions happen to be used only by loadable modules, in
which case the arch and base CRC32 modules will be automatically loaded
via direct symbol dependency when appropriate.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2024-11-26T00:09:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-11-26T00:09:48+00:00 f5f4745a7f057b58c9728ee4e2c5d6d79f382fe7 Pull non-MM updates from Andrew Morton: - The series "resource: A couple of cleanups" from Andy Shevchenko performs some cleanups in the resource management code - The series "Improve the copy of task comm" from Yafang Shao addresses possible race-induced overflows in the management of task_struct.comm[] - The series "Remove unnecessary header includes from {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a small fix to the list_sort library code and to its selftest - The series "Enhance min heap API with non-inline functions and optimizations" also from Kuan-Wei Chiu optimizes and cleans up the min_heap library code - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi finishes off nilfs2's folioification - The series "add detect count for hung tasks" from Lance Yang adds more userspace visibility into the hung-task detector's activity - Apart from that, singelton patches in many places - please see the individual changelogs for details * tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits) gdb: lx-symbols: do not error out on monolithic build kernel/reboot: replace sprintf() with sysfs_emit() lib: util_macros_kunit: add kunit test for util_macros.h util_macros.h: fix/rework find_closest() macros Improve consistency of '#error' directive messages ocfs2: fix uninitialized value in ocfs2_file_read_iter() hung_task: add docs for hung_task_detect_count hung_task: add detect count for hung tasks dma-buf: use atomic64_inc_return() in dma_buf_getfile() fs/proc/kcore.c: fix coccinelle reported ERROR instances resource: avoid unnecessary resource tree walking in __region_intersects() ocfs2: remove unused errmsg function and table ocfs2: cluster: fix a typo lib/scatterlist: use sg_phys() helper checkpatch: always parse orig_commit in fixes tag nilfs2: convert metadata aops from writepage to writepages nilfs2: convert nilfs_recovery_copy_block() to take a folio nilfs2: convert nilfs_page_count_clean_buffers() to take a folio nilfs2: remove nilfs_writepage nilfs2: convert checkpoint file to be folio-based ... 
Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...
lib/min_heap: introduce non-inline versions of min heap API functions 2024-11-06T01:12:34+00:00 Kuan-Wei Chiu visitorckw@gmail.com 2024-10-20T04:01:51+00:00 92a8b224b833e82d286d2100432adbac8cf8a2a1 Patch series "Enhance min heap API with non-inline functions and optimizations", v2. Add non-inline versions of the min heap API functions in lib/min_heap.c and updates all users outside of kernel/events/core.c to use these non-inline versions. To mitigate the performance impact of indirect function calls caused by the non-inline versions of the swap and compare functions, a builtin swap has been introduced that swaps elements based on their size. Additionally, it micro-optimizes the efficiency of the min heap by pre-scaling the counter, following the same approach as in lib/sort.c. Documentation for the min heap API has also been added to the core-api section. This patch (of 10): All current min heap API functions are marked with '__always_inline'. However, as the number of users increases, inlining these functions everywhere leads to a increase in kernel size. In performance-critical paths, such as when perf events are enabled and min heap functions are called on every context switch, it is important to retain the inline versions for optimal performance. To balance this, the original inline functions are kept, and additional non-inline versions of the functions have been added in lib/min_heap.c. Link: https://lkml.kernel.org/r/20241020040200.939973-1-visitorckw@gmail.com Link: https://lore.kernel.org/20240522161048.8d8bbc7b153b4ecd92c50666@linux-foundation.org Link: https://lkml.kernel.org/r/20241020040200.939973-2-visitorckw@gmail.com Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Cc: Coly Li <colyli@suse.de> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Kuan-Wei Chiu <visitorckw@gmail.com> Cc: "Liang, Kan" <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Sakai <msakai@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Patch series "Enhance min heap API with non-inline functions and
optimizations", v2.

Add non-inline versions of the min heap API functions in lib/min_heap.c
and updates all users outside of kernel/events/core.c to use these
non-inline versions.  To mitigate the performance impact of indirect
function calls caused by the non-inline versions of the swap and compare
functions, a builtin swap has been introduced that swaps elements based on
their size.  Additionally, it micro-optimizes the efficiency of the min
heap by pre-scaling the counter, following the same approach as in
lib/sort.c.  Documentation for the min heap API has also been added to the
core-api section.


This patch (of 10):

All current min heap API functions are marked with '__always_inline'. 
However, as the number of users increases, inlining these functions
everywhere leads to a increase in kernel size.

In performance-critical paths, such as when perf events are enabled and
min heap functions are called on every context switch, it is important to
retain the inline versions for optimal performance.  To balance this, the
original inline functions are kept, and additional non-inline versions of
the functions have been added in lib/min_heap.c.

Link: https://lkml.kernel.org/r/20241020040200.939973-1-visitorckw@gmail.com
Link: https://lore.kernel.org/20240522161048.8d8bbc7b153b4ecd92c50666@linux-foundation.org
Link: https://lkml.kernel.org/r/20241020040200.939973-2-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Kuan-Wei Chiu <visitorckw@gmail.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
lib/Makefile: make union-find compilation conditional on CONFIG_CPUSETS 2024-11-06T01:12:32+00:00 Kuan-Wei Chiu visitorckw@gmail.com 2024-10-11T14:12:14+00:00 bf9850f6ea3577a099b0ed43f6e19ca43ef08704 Currently, cpuset is the only user of the union-find implementation. Compiling union-find in all configurations unnecessarily increases the code size when building the kernel without cgroup support. Modify the build system to compile union-find only when CONFIG_CPUSETS is enabled. Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/ Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Suggested-by: Waiman Long <llong@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Xavier <xavier_qy@163.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Currently, cpuset is the only user of the union-find implementation. 
Compiling union-find in all configurations unnecessarily increases the
code size when building the kernel without cgroup support.  Modify the
build system to compile union-find only when CONFIG_CPUSETS is enabled.

Link: https://lore.kernel.org/lkml/1ccd6411-5002-4574-bb8e-3e64bba6a757@redhat.com/
Link: https://lkml.kernel.org/r/20241011141214.87096-1-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Waiman Long <llong@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Xavier <xavier_qy@163.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>