<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/Documentation/admin-guide/sysctl, branch v6.12.80</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>coredump: Only sort VMAs when core_sort_vma sysctl is set</title>
<updated>2025-03-13T12:02:01+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2025-02-19T19:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5481dee296f60d94f7b5317158a336f8d722d000'/>
<id>5481dee296f60d94f7b5317158a336f8d722d000</id>
<content type='text'>
[ Upstream commit 39ec9eaaa165d297d008d1fa385748430bd18e4d ]

The sorting of VMAs by size in commit 7d442a33bfe8 ("binfmt_elf: Dump
smaller VMAs first in ELF cores") breaks elfutils[1]. Instead, sort
based on the setting of the new sysctl, core_sort_vma, which defaults
to 0, no sorting.

Reported-by: Michael Stapelberg &lt;michael@stapelberg.ch&gt;
Closes: https://lore.kernel.org/all/20250218085407.61126-1-michael@stapelberg.de/ [1]
Fixes: 7d442a33bfe8 ("binfmt_elf: Dump smaller VMAs first in ELF cores")
Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 39ec9eaaa165d297d008d1fa385748430bd18e4d ]

The sorting of VMAs by size in commit 7d442a33bfe8 ("binfmt_elf: Dump
smaller VMAs first in ELF cores") breaks elfutils[1]. Instead, sort
based on the setting of the new sysctl, core_sort_vma, which defaults
to 0, no sorting.

Reported-by: Michael Stapelberg &lt;michael@stapelberg.ch&gt;
Closes: https://lore.kernel.org/all/20250218085407.61126-1-michael@stapelberg.de/ [1]
Fixes: 7d442a33bfe8 ("binfmt_elf: Dump smaller VMAs first in ELF cores")
Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'parisc-for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux</title>
<updated>2024-07-25T19:37:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-25T19:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f6464295247dd04b2070e110f0d5659577e393b9'/>
<id>f6464295247dd04b2070e110f0d5659577e393b9</id>
<content type='text'>
Pull parisc updates from Helge Deller:
 "The gettimeofday() and clock_gettime() syscalls are now available as
  vDSO functions, and Dave added a patch which allows to use NVMe cards
  in the PCI slots as fast and easy alternative to SCSI discs.

  Summary:

   - add gettimeofday() and clock_gettime() vDSO functions

   - enable PCI_MSI_ARCH_FALLBACKS to allow PCI to PCIe bridge adaptor
     with PCIe NVME card to function in parisc machines

   - allow users to reduce kernel unaligned runtime warnings

   - minor code cleanups"

* tag 'parisc-for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
  parisc: Use max() to calculate parisc_tlb_flush_threshold
  parisc: Fix warning at drivers/pci/msi/msi.h:121
  parisc: Add 64-bit gettimeofday() and clock_gettime() vDSO functions
  parisc: Add 32-bit gettimeofday() and clock_gettime() vDSO functions
  parisc: Clean up unistd.h file
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull parisc updates from Helge Deller:
 "The gettimeofday() and clock_gettime() syscalls are now available as
  vDSO functions, and Dave added a patch which allows to use NVMe cards
  in the PCI slots as fast and easy alternative to SCSI discs.

  Summary:

   - add gettimeofday() and clock_gettime() vDSO functions

   - enable PCI_MSI_ARCH_FALLBACKS to allow PCI to PCIe bridge adaptor
     with PCIe NVME card to function in parisc machines

   - allow users to reduce kernel unaligned runtime warnings

   - minor code cleanups"

* tag 'parisc-for-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
  parisc: Use max() to calculate parisc_tlb_flush_threshold
  parisc: Fix warning at drivers/pci/msi/msi.h:121
  parisc: Add 64-bit gettimeofday() and clock_gettime() vDSO functions
  parisc: Add 32-bit gettimeofday() and clock_gettime() vDSO functions
  parisc: Clean up unistd.h file
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: Add support for CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN</title>
<updated>2024-07-24T00:04:05+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2024-07-21T21:36:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=cbade823342cd013f1fbd46f6e3b74825fecbc16'/>
<id>cbade823342cd013f1fbd46f6e3b74825fecbc16</id>
<content type='text'>
Allow users to disable kernel warnings for unaligned memory
accesses from kernel via the /proc/sys/kernel/ignore-unaligned-usertrap
procfs entry.
That way users can disable those warnings in case they happen too
often.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Allow users to disable kernel warnings for unaligned memory
accesses from kernel via the /proc/sys/kernel/ignore-unaligned-usertrap
procfs entry.
That way users can disable those warnings in case they happen too
often.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>docs: mm: add enable_soft_offline sysctl</title>
<updated>2024-07-05T01:06:00+00:00</updated>
<author>
<name>Jiaqi Yan</name>
<email>jiaqiyan@google.com</email>
</author>
<published>2024-06-26T05:08:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=44195d1eba826a8af0afbcfa69ab4cc26f6ead7f'/>
<id>44195d1eba826a8af0afbcfa69ab4cc26f6ead7f</id>
<content type='text'>
Add the documentation for soft offline behaviors / costs, and what the new
enable_soft_offline sysctl is for.

[jiaqiyan@google.com: fix kerneldoc warnings]
  Link: https://lkml.kernel.org/r/CACw3F52=GxTCDw-PqFh3-GDM-fo3GbhGdu0hedxYXOTT4TQSTg@mail.gmail.com
[jiaqiyan@google.com: there are more blank lines needed]
  Link: https://lkml.kernel.org/r/CACw3F52_obAB742XeDRNun4BHBYtrxtbvp5NkUincXdaob0j1g@mail.gmail.com
Link: https://lkml.kernel.org/r/20240626050818.2277273-5-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan &lt;jiaqiyan@google.com&gt;
Acked-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Acked-by: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Frank van der Linden &lt;fvdl@google.com&gt;
Cc: Jane Chu &lt;jane.chu@oracle.com&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Lance Yang &lt;ioworker0@gmail.com&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the documentation for soft offline behaviors / costs, and what the new
enable_soft_offline sysctl is for.

[jiaqiyan@google.com: fix kerneldoc warnings]
  Link: https://lkml.kernel.org/r/CACw3F52=GxTCDw-PqFh3-GDM-fo3GbhGdu0hedxYXOTT4TQSTg@mail.gmail.com
[jiaqiyan@google.com: there are more blank lines needed]
  Link: https://lkml.kernel.org/r/CACw3F52_obAB742XeDRNun4BHBYtrxtbvp5NkUincXdaob0j1g@mail.gmail.com
Link: https://lkml.kernel.org/r/20240626050818.2277273-5-jiaqiyan@google.com
Signed-off-by: Jiaqi Yan &lt;jiaqiyan@google.com&gt;
Acked-by: Oscar Salvador &lt;osalvador@suse.de&gt;
Acked-by: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Frank van der Linden &lt;fvdl@google.com&gt;
Cc: Jane Chu &lt;jane.chu@oracle.com&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Lance Yang &lt;ioworker0@gmail.com&gt;
Cc: Muchun Song &lt;muchun.song@linux.dev&gt;
Cc: Naoya Horiguchi &lt;nao.horiguchi@gmail.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Shuah Khan &lt;shuah@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-05-19T16:21:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-05-19T16:21:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=61307b7be41a1f1039d1d1368810a1d92cb97b44'/>
<id>61307b7be41a1f1039d1d1368810a1d92cb97b44</id>
<content type='text'>
Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page-&gt;flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize -&gt;esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page-&gt;flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize -&gt;esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>ARC: Add eBPF JIT support</title>
<updated>2024-05-12T23:51:36+00:00</updated>
<author>
<name>Shahab Vahedi</name>
<email>shahab@synopsys.com</email>
</author>
<published>2024-04-30T14:56:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f122668ddcce450c2585f0be4bf4478d6fd6176b'/>
<id>f122668ddcce450c2585f0be4bf4478d6fd6176b</id>
<content type='text'>
This will add eBPF JIT support to the 32-bit ARCv2 processors. The
implementation is qualified by running the BPF tests on a Synopsys HSDK
board with "ARC HS38 v2.1c at 500 MHz" as the 4-core CPU.

The test_bpf.ko reports 2-10 fold improvements in execution time of its
tests. For instance:

test_bpf: #33 tcpdump port 22 jited:0 704 1766 2104 PASS
test_bpf: #33 tcpdump port 22 jited:1 120  224  260 PASS

test_bpf: #141 ALU_DIV_X: 4294967295 / 4294967295 = 1 jited:0 238 PASS
test_bpf: #141 ALU_DIV_X: 4294967295 / 4294967295 = 1 jited:1  23 PASS

test_bpf: #776 JMP32_JGE_K: all ... magnitudes jited:0 2034681 PASS
test_bpf: #776 JMP32_JGE_K: all ... magnitudes jited:1 1020022 PASS

Deployment and structure
------------------------
The related codes are added to "arch/arc/net":

- bpf_jit.h       -- The interface that a back-end translator must provide
- bpf_jit_core.c  -- Knows how to handle the input eBPF byte stream
- bpf_jit_arcv2.c -- The back-end code that knows the translation logic

The bpf_int_jit_compile() at the end of bpf_jit_core.c is the entrance
to the whole process. Normally, the translation is done in one pass,
namely the "normal pass". In case some relocations are not known during
this pass, some data (arc_jit_data) is allocated for the next pass to
come. This possible next (and last) pass is called the "extra pass".

1. Normal pass       # The necessary pass
     1a. Dry run       # Get the whole JIT length, epilogue offset, etc.
     1b. Emit phase    # Allocate memory and start emitting instructions
2. Extra pass        # Only needed if there are relocations to be fixed
     2a. Patch relocations

Support status
--------------
The JIT compiler supports BPF instructions up to "cpu=v4". However, it
does not yet provide support for:

- Tail calls
- Atomic operations
- 64-bit division/remainder
- BPF_PROBE_MEM* (exception table)

The result of "test_bpf" test suite on an HSDK board is:

hsdk-lnx# insmod test_bpf.ko test_suite=test_bpf

  test_bpf: Summary: 863 PASSED, 186 FAILED, [851/851 JIT'ed]

All the failing test cases are due to the ones that were not JIT'ed.
Categorically, they can be represented as:

  .-----------.------------.-------------.
  | test type |   opcodes  | # of cases  |
  |-----------+------------+-------------|
  | atomic    | 0xC3, 0xDB |         149 |
  | div64     | 0x37, 0x3F |          22 |
  | mod64     | 0x97, 0x9F |          15 |
  `-----------^------------+-------------|
                           | (total) 186 |
                           `-------------'

Setup: build config
-------------------
The following configs must be set to have a working JIT test:

  CONFIG_BPF_JIT=y
  CONFIG_BPF_JIT_ALWAYS_ON=y
  CONFIG_TEST_BPF=m

The following options are not necessary for the tests module,
but are good to have:

  CONFIG_DEBUG_INFO=y             # prerequisite for below
  CONFIG_DEBUG_INFO_BTF=y         # so bpftool can generate vmlinux.h

  CONFIG_FTRACE=y                 #
  CONFIG_BPF_SYSCALL=y            # all these options lead to
  CONFIG_KPROBE_EVENTS=y          # having CONFIG_BPF_EVENTS=y
  CONFIG_PERF_EVENTS=y            #

Some BPF programs provide data through /sys/kernel/debug:
  CONFIG_DEBUG_FS=y
arc# mount -t debugfs debugfs /sys/kernel/debug

Setup: elfutils
---------------
The libdw.{so,a} library that is used by pahole for processing
the final binary must come from elfutils 0.189 or newer. The
support for ARCv2 [1] has been added since that version.

[1]
https://sourceware.org/git/?p=elfutils.git;a=commit;h=de3d46b3e7

Setup: pahole
-------------
The line below in linux/scripts/Makefile.btf must be commented out:

pahole-flags-$(call test-ge, $(pahole-ver), 121) += --btf_gen_floats

Or else, the build will fail:

$ make V=1
  ...
  BTF     .btf.vmlinux.bin.o
pahole -J --btf_gen_floats                    \
       -j --lang_exclude=rust                 \
       --skip_encoding_btf_inconsistent_proto \
       --btf_gen_optimized .tmp_vmlinux.btf
Complex, interval and imaginary float types are not supported
Encountered error while encoding BTF.
  ...
  BTFIDS  vmlinux
./tools/bpf/resolve_btfids/resolve_btfids vmlinux
libbpf: failed to find '.BTF' ELF section in vmlinux
FAILED: load BTF from vmlinux: No data available

This is due to the fact that the ARC toolchains generate
"complex float" DIE entries in libgcc and at the moment, pahole
can't handle such entries.

Running the tests
-----------------
host$ scp /bld/linux/lib/test_bpf.ko arc:
arc # sysctl net.core.bpf_jit_enable=1
arc # insmod test_bpf.ko test_suite=test_bpf
      ...
      test_bpf: #1048 Staggered jumps: JMP32_JSLE_X jited:1 697811 PASS
      test_bpf: Summary: 863 PASSED, 186 FAILED, [851/851 JIT'ed]

Acknowledgments
---------------
- Claudiu Zissulescu for his unwavering support
- Yuriy Kolerov for testing and troubleshooting
- Vladimir Isaev for the pahole workaround
- Sergey Matyukevich for paving the road by adding the interpreter support

Signed-off-by: Shahab Vahedi &lt;shahab@synopsys.com&gt;
Link: https://lore.kernel.org/r/20240430145604.38592-1-list+bpf@vahedi.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This will add eBPF JIT support to the 32-bit ARCv2 processors. The
implementation is qualified by running the BPF tests on a Synopsys HSDK
board with "ARC HS38 v2.1c at 500 MHz" as the 4-core CPU.

The test_bpf.ko reports 2-10 fold improvements in execution time of its
tests. For instance:

test_bpf: #33 tcpdump port 22 jited:0 704 1766 2104 PASS
test_bpf: #33 tcpdump port 22 jited:1 120  224  260 PASS

test_bpf: #141 ALU_DIV_X: 4294967295 / 4294967295 = 1 jited:0 238 PASS
test_bpf: #141 ALU_DIV_X: 4294967295 / 4294967295 = 1 jited:1  23 PASS

test_bpf: #776 JMP32_JGE_K: all ... magnitudes jited:0 2034681 PASS
test_bpf: #776 JMP32_JGE_K: all ... magnitudes jited:1 1020022 PASS

Deployment and structure
------------------------
The related codes are added to "arch/arc/net":

- bpf_jit.h       -- The interface that a back-end translator must provide
- bpf_jit_core.c  -- Knows how to handle the input eBPF byte stream
- bpf_jit_arcv2.c -- The back-end code that knows the translation logic

The bpf_int_jit_compile() at the end of bpf_jit_core.c is the entrance
to the whole process. Normally, the translation is done in one pass,
namely the "normal pass". In case some relocations are not known during
this pass, some data (arc_jit_data) is allocated for the next pass to
come. This possible next (and last) pass is called the "extra pass".

1. Normal pass       # The necessary pass
     1a. Dry run       # Get the whole JIT length, epilogue offset, etc.
     1b. Emit phase    # Allocate memory and start emitting instructions
2. Extra pass        # Only needed if there are relocations to be fixed
     2a. Patch relocations

Support status
--------------
The JIT compiler supports BPF instructions up to "cpu=v4". However, it
does not yet provide support for:

- Tail calls
- Atomic operations
- 64-bit division/remainder
- BPF_PROBE_MEM* (exception table)

The result of "test_bpf" test suite on an HSDK board is:

hsdk-lnx# insmod test_bpf.ko test_suite=test_bpf

  test_bpf: Summary: 863 PASSED, 186 FAILED, [851/851 JIT'ed]

All the failing test cases are due to the ones that were not JIT'ed.
Categorically, they can be represented as:

  .-----------.------------.-------------.
  | test type |   opcodes  | # of cases  |
  |-----------+------------+-------------|
  | atomic    | 0xC3, 0xDB |         149 |
  | div64     | 0x37, 0x3F |          22 |
  | mod64     | 0x97, 0x9F |          15 |
  `-----------^------------+-------------|
                           | (total) 186 |
                           `-------------'

Setup: build config
-------------------
The following configs must be set to have a working JIT test:

  CONFIG_BPF_JIT=y
  CONFIG_BPF_JIT_ALWAYS_ON=y
  CONFIG_TEST_BPF=m

The following options are not necessary for the tests module,
but are good to have:

  CONFIG_DEBUG_INFO=y             # prerequisite for below
  CONFIG_DEBUG_INFO_BTF=y         # so bpftool can generate vmlinux.h

  CONFIG_FTRACE=y                 #
  CONFIG_BPF_SYSCALL=y            # all these options lead to
  CONFIG_KPROBE_EVENTS=y          # having CONFIG_BPF_EVENTS=y
  CONFIG_PERF_EVENTS=y            #

Some BPF programs provide data through /sys/kernel/debug:
  CONFIG_DEBUG_FS=y
arc# mount -t debugfs debugfs /sys/kernel/debug

Setup: elfutils
---------------
The libdw.{so,a} library that is used by pahole for processing
the final binary must come from elfutils 0.189 or newer. The
support for ARCv2 [1] has been added since that version.

[1]
https://sourceware.org/git/?p=elfutils.git;a=commit;h=de3d46b3e7

Setup: pahole
-------------
The line below in linux/scripts/Makefile.btf must be commented out:

pahole-flags-$(call test-ge, $(pahole-ver), 121) += --btf_gen_floats

Or else, the build will fail:

$ make V=1
  ...
  BTF     .btf.vmlinux.bin.o
pahole -J --btf_gen_floats                    \
       -j --lang_exclude=rust                 \
       --skip_encoding_btf_inconsistent_proto \
       --btf_gen_optimized .tmp_vmlinux.btf
Complex, interval and imaginary float types are not supported
Encountered error while encoding BTF.
  ...
  BTFIDS  vmlinux
./tools/bpf/resolve_btfids/resolve_btfids vmlinux
libbpf: failed to find '.BTF' ELF section in vmlinux
FAILED: load BTF from vmlinux: No data available

This is due to the fact that the ARC toolchains generate
"complex float" DIE entries in libgcc and at the moment, pahole
can't handle such entries.

Running the tests
-----------------
host$ scp /bld/linux/lib/test_bpf.ko arc:
arc # sysctl net.core.bpf_jit_enable=1
arc # insmod test_bpf.ko test_suite=test_bpf
      ...
      test_bpf: #1048 Staggered jumps: JMP32_JSLE_X jited:1 697811 PASS
      test_bpf: Summary: 863 PASSED, 186 FAILED, [851/851 JIT'ed]

Acknowledgments
---------------
- Claudiu Zissulescu for his unwavering support
- Yuriy Kolerov for testing and troubleshooting
- Vladimir Isaev for the pahole workaround
- Sergey Matyukevich for paving the road by adding the interpreter support

Signed-off-by: Shahab Vahedi &lt;shahab@synopsys.com&gt;
Link: https://lore.kernel.org/r/20240430145604.38592-1-list+bpf@vahedi.org
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>lib: add allocation tagging support for memory allocation profiling</title>
<updated>2024-04-26T03:55:52+00:00</updated>
<author>
<name>Suren Baghdasaryan</name>
<email>surenb@google.com</email>
</author>
<published>2024-03-21T16:36:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=22d407b164ff79de42d21f37d99f9ee7abdd51c8'/>
<id>22d407b164ff79de42d21f37d99f9ee7abdd51c8</id>
<content type='text'>
Introduce CONFIG_MEM_ALLOC_PROFILING which provides definitions to easily
instrument memory allocators.  It registers an "alloc_tags" codetag type
with /proc/allocinfo interface to output allocation tag information when
the feature is enabled.

CONFIG_MEM_ALLOC_PROFILING_DEBUG is provided for debugging the memory
allocation profiling instrumentation.

Memory allocation profiling can be enabled or disabled at runtime using
/proc/sys/vm/mem_profiling sysctl when CONFIG_MEM_ALLOC_PROFILING_DEBUG=n.
CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT enables memory allocation
profiling by default.

[surenb@google.com: Documentation/filesystems/proc.rst: fix allocinfo title]
  Link: https://lkml.kernel.org/r/20240326073813.727090-1-surenb@google.com
[surenb@google.com: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU]
  Link: https://lkml.kernel.org/r/20240402180933.1663992-2-surenb@google.com
[klarasmodin@gmail.com: explicitly include irqflags.h in alloc_tag.h]
  Link: https://lkml.kernel.org/r/20240407133252.173636-1-klarasmodin@gmail.com
[surenb@google.com: fix alloc_tag_init() to prevent passing NULL to PTR_ERR()]
  Link: https://lkml.kernel.org/r/20240417003349.2520094-1-surenb@google.com
Link: https://lkml.kernel.org/r/20240321163705.3067592-14-surenb@google.com
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Co-developed-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
Signed-off-by: Klara Modin &lt;klarasmodin@gmail.com&gt;
Tested-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Alex Gaynor &lt;alex.gaynor@gmail.com&gt;
Cc: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Andreas Hindborg &lt;a.hindborg@samsung.com&gt;
Cc: Benno Lossin &lt;benno.lossin@proton.me&gt;
Cc: "Björn Roy Baron" &lt;bjorn3_gh@protonmail.com&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Dennis Zhou &lt;dennis@kernel.org&gt;
Cc: Gary Guo &lt;gary@garyguo.net&gt;
Cc: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Cc: Pasha Tatashin &lt;pasha.tatashin@soleen.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Wedson Almeida Filho &lt;wedsonaf@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce CONFIG_MEM_ALLOC_PROFILING which provides definitions to easily
instrument memory allocators.  It registers an "alloc_tags" codetag type
with /proc/allocinfo interface to output allocation tag information when
the feature is enabled.

CONFIG_MEM_ALLOC_PROFILING_DEBUG is provided for debugging the memory
allocation profiling instrumentation.

Memory allocation profiling can be enabled or disabled at runtime using
/proc/sys/vm/mem_profiling sysctl when CONFIG_MEM_ALLOC_PROFILING_DEBUG=n.
CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT enables memory allocation
profiling by default.

[surenb@google.com: Documentation/filesystems/proc.rst: fix allocinfo title]
  Link: https://lkml.kernel.org/r/20240326073813.727090-1-surenb@google.com
[surenb@google.com: do limited memory accounting for modules with ARCH_NEEDS_WEAK_PER_CPU]
  Link: https://lkml.kernel.org/r/20240402180933.1663992-2-surenb@google.com
[klarasmodin@gmail.com: explicitly include irqflags.h in alloc_tag.h]
  Link: https://lkml.kernel.org/r/20240407133252.173636-1-klarasmodin@gmail.com
[surenb@google.com: fix alloc_tag_init() to prevent passing NULL to PTR_ERR()]
  Link: https://lkml.kernel.org/r/20240417003349.2520094-1-surenb@google.com
Link: https://lkml.kernel.org/r/20240321163705.3067592-14-surenb@google.com
Signed-off-by: Suren Baghdasaryan &lt;surenb@google.com&gt;
Co-developed-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
Signed-off-by: Klara Modin &lt;klarasmodin@gmail.com&gt;
Tested-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Alex Gaynor &lt;alex.gaynor@gmail.com&gt;
Cc: Alice Ryhl &lt;aliceryhl@google.com&gt;
Cc: Andreas Hindborg &lt;a.hindborg@samsung.com&gt;
Cc: Benno Lossin &lt;benno.lossin@proton.me&gt;
Cc: "Björn Roy Baron" &lt;bjorn3_gh@protonmail.com&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Dennis Zhou &lt;dennis@kernel.org&gt;
Cc: Gary Guo &lt;gary@garyguo.net&gt;
Cc: Miguel Ojeda &lt;ojeda@kernel.org&gt;
Cc: Pasha Tatashin &lt;pasha.tatashin@soleen.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Wedson Almeida Filho &lt;wedsonaf@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace</title>
<updated>2024-03-18T22:11:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-18T22:11:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ad584d73a22b2f6e6b4c928956fdece5c44cdb3e'/>
<id>ad584d73a22b2f6e6b4c928956fdece5c44cdb3e</id>
<content type='text'>
Pull tracing updates from Steven Rostedt:
 "Main user visible change:

   - User events can now have "multi formats"

     The current user events have a single format. If another event is
     created with a different format, it will fail to be created. That
     is, once an event name is used, it cannot be used again with a
     different format. This can cause issues if a library is using an
     event and updates its format. An application using the older format
     will prevent an application using the new library from registering
     its event.

     A task could also DOS another application if it knows the event
     names, and it creates events with different formats.

     The multi-format event is in a different name space from the single
     format. Both the event name and its format are the unique
     identifier. This will allow two different applications to use the
     same user event name but with different payloads.

   - Added support to have ftrace_dump_on_oops dump out instances and
     not just the main top level tracing buffer.

  Other changes:

   - Add eventfs_root_inode

     Only the root inode has a dentry that is static (never goes away)
     and stores it upon creation. There's no reason that the thousands
     of other eventfs inodes should have a pointer that never gets set
     in its descriptor. Create a eventfs_root_inode desciptor that has a
     eventfs_inode descriptor and a dentry pointer, and only the root
     inode will use this.

   - Added WARN_ON()s in eventfs

     There's some conditionals remaining in eventfs that should never be
     hit, but instead of removing them, add WARN_ON() around them to
     make sure that they are never hit.

   - Have saved_cmdlines allocation also include the map_cmdline_to_pid
     array

     The saved_cmdlines structure allocates a large amount of data to
     hold its mappings. Within it, it has three arrays. Two are already
     apart of it: map_pid_to_cmdline[] and saved_cmdlines[]. More memory
     can be saved by also including the map_cmdline_to_pid[] array as
     well.

   - Restructure __string() and __assign_str() macros used in
     TRACE_EVENT()

     Dynamic strings in TRACE_EVENT() are declared with:

         __string(name, source)

     And assigned with:

        __assign_str(name, source)

     In the tracepoint callback of the event, the __string() is used to
     get the size needed to allocate on the ring buffer and
     __assign_str() is used to copy the string into the ring buffer.
     There's a helper structure that is created in the TRACE_EVENT()
     macro logic that will hold the string length and its position in
     the ring buffer which is created by __string().

     There are several trace events that have a function to create the
     string to save. This function is executed twice. Once for
     __string() and again for __assign_str(). There's no reason for
     this. The helper structure could also save the string it used in
     __string() and simply copy that into __assign_str() (it also
     already has its length).

     By using the structure to store the source string for the
     assignment, it means that the second argument to __assign_str() is
     no longer needed.

     It will be removed in the next merge window, but for now add a
     warning if the source string given to __string() is different than
     the source string given to __assign_str(), as the source to
     __assign_str() isn't even used and will be going away.

   - Added checks to make sure that the source of __string() is also the
     source of __assign_str() so that it can be safely removed in the
     next merge window.

     Included fixes that the above check found.

   - Other minor clean ups and fixes"

* tag 'trace-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
  tracing: Add __string_src() helper to help compilers not to get confused
  tracing: Use strcmp() in __assign_str() WARN_ON() check
  tracepoints: Use WARN() and not WARN_ON() for warnings
  tracing: Use div64_u64() instead of do_div()
  tracing: Support to dump instance traces by ftrace_dump_on_oops
  tracing: Remove second parameter to __assign_rel_str()
  tracing: Add warning if string in __assign_str() does not match __string()
  tracing: Add __string_len() example
  tracing: Remove __assign_str_len()
  ftrace: Fix most kernel-doc warnings
  tracing: Decrement the snapshot if the snapshot trigger fails to register
  tracing: Fix snapshot counter going between two tracers that use it
  tracing: Use EVENT_NULL_STR macro instead of open coding "(null)"
  tracing: Use ? : shortcut in trace macros
  tracing: Do not calculate strlen() twice for __string() fields
  tracing: Rework __assign_str() and __string() to not duplicate getting the string
  cxl/trace: Properly initialize cxl_poison region name
  net: hns3: tracing: fix hclgevf trace event strings
  drm/i915: Add missing ; to __assign_str() macros in tracepoint code
  NFSD: Fix nfsd_clid_class use of __string_len() macro
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing updates from Steven Rostedt:
 "Main user visible change:

   - User events can now have "multi formats"

     The current user events have a single format. If another event is
     created with a different format, it will fail to be created. That
     is, once an event name is used, it cannot be used again with a
     different format. This can cause issues if a library is using an
     event and updates its format. An application using the older format
     will prevent an application using the new library from registering
     its event.

     A task could also DOS another application if it knows the event
     names, and it creates events with different formats.

     The multi-format event is in a different name space from the single
     format. Both the event name and its format are the unique
     identifier. This will allow two different applications to use the
     same user event name but with different payloads.

   - Added support to have ftrace_dump_on_oops dump out instances and
     not just the main top level tracing buffer.

  Other changes:

   - Add eventfs_root_inode

     Only the root inode has a dentry that is static (never goes away)
     and stores it upon creation. There's no reason that the thousands
     of other eventfs inodes should have a pointer that never gets set
     in its descriptor. Create a eventfs_root_inode desciptor that has a
     eventfs_inode descriptor and a dentry pointer, and only the root
     inode will use this.

   - Added WARN_ON()s in eventfs

     There's some conditionals remaining in eventfs that should never be
     hit, but instead of removing them, add WARN_ON() around them to
     make sure that they are never hit.

   - Have saved_cmdlines allocation also include the map_cmdline_to_pid
     array

     The saved_cmdlines structure allocates a large amount of data to
     hold its mappings. Within it, it has three arrays. Two are already
     apart of it: map_pid_to_cmdline[] and saved_cmdlines[]. More memory
     can be saved by also including the map_cmdline_to_pid[] array as
     well.

   - Restructure __string() and __assign_str() macros used in
     TRACE_EVENT()

     Dynamic strings in TRACE_EVENT() are declared with:

         __string(name, source)

     And assigned with:

        __assign_str(name, source)

     In the tracepoint callback of the event, the __string() is used to
     get the size needed to allocate on the ring buffer and
     __assign_str() is used to copy the string into the ring buffer.
     There's a helper structure that is created in the TRACE_EVENT()
     macro logic that will hold the string length and its position in
     the ring buffer which is created by __string().

     There are several trace events that have a function to create the
     string to save. This function is executed twice. Once for
     __string() and again for __assign_str(). There's no reason for
     this. The helper structure could also save the string it used in
     __string() and simply copy that into __assign_str() (it also
     already has its length).

     By using the structure to store the source string for the
     assignment, it means that the second argument to __assign_str() is
     no longer needed.

     It will be removed in the next merge window, but for now add a
     warning if the source string given to __string() is different than
     the source string given to __assign_str(), as the source to
     __assign_str() isn't even used and will be going away.

   - Added checks to make sure that the source of __string() is also the
     source of __assign_str() so that it can be safely removed in the
     next merge window.

     Included fixes that the above check found.

   - Other minor clean ups and fixes"

* tag 'trace-v6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
  tracing: Add __string_src() helper to help compilers not to get confused
  tracing: Use strcmp() in __assign_str() WARN_ON() check
  tracepoints: Use WARN() and not WARN_ON() for warnings
  tracing: Use div64_u64() instead of do_div()
  tracing: Support to dump instance traces by ftrace_dump_on_oops
  tracing: Remove second parameter to __assign_rel_str()
  tracing: Add warning if string in __assign_str() does not match __string()
  tracing: Add __string_len() example
  tracing: Remove __assign_str_len()
  ftrace: Fix most kernel-doc warnings
  tracing: Decrement the snapshot if the snapshot trigger fails to register
  tracing: Fix snapshot counter going between two tracers that use it
  tracing: Use EVENT_NULL_STR macro instead of open coding "(null)"
  tracing: Use ? : shortcut in trace macros
  tracing: Do not calculate strlen() twice for __string() fields
  tracing: Rework __assign_str() and __string() to not duplicate getting the string
  cxl/trace: Properly initialize cxl_poison region name
  net: hns3: tracing: fix hclgevf trace event strings
  drm/i915: Add missing ; to __assign_str() macros in tracepoint code
  NFSD: Fix nfsd_clid_class use of __string_len() macro
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>tracing: Support to dump instance traces by ftrace_dump_on_oops</title>
<updated>2024-03-18T14:33:06+00:00</updated>
<author>
<name>Huang Yiwei</name>
<email>quic_hyiwei@quicinc.com</email>
</author>
<published>2024-02-23T08:31:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=19f0423fd55c301c8edaea286e568ec657f42750'/>
<id>19f0423fd55c301c8edaea286e568ec657f42750</id>
<content type='text'>
Currently ftrace only dumps the global trace buffer on an OOPs. For
debugging a production usecase, instance trace will be helpful to
check specific problems since global trace buffer may be used for
other purposes.

This patch extend the ftrace_dump_on_oops parameter to dump a specific
or multiple trace instances:

  - ftrace_dump_on_oops=0: as before -- don't dump
  - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer
  on all CPUs
  - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global
  trace buffer on CPU that triggered the oops
  - ftrace_dump_on_oops=&lt;instance_name&gt;: new behavior -- dump the
  tracing instance matching &lt;instance_name&gt;
  - ftrace_dump_on_oops[=2/orig_cpu],&lt;instance1_name&gt;[=2/orig_cpu],
  &lt;instrance2_name&gt;[=2/orig_cpu]: new behavior -- dump the global trace
  buffer and multiple instance buffer on all CPUs, or only dump on CPU
  that triggered the oops if =2 or =orig_cpu is given

Also, the sysctl node can handle the input accordingly.

Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com

Cc: Ross Zwisler &lt;zwisler@google.com&gt;
Cc: &lt;mhiramat@kernel.org&gt;
Cc: &lt;mark.rutland@arm.com&gt;
Cc: &lt;mcgrof@kernel.org&gt;
Cc: &lt;keescook@chromium.org&gt;
Cc: &lt;j.granados@samsung.com&gt;
Cc: &lt;mathieu.desnoyers@efficios.com&gt;
Cc: &lt;corbet@lwn.net&gt;
Signed-off-by: Huang Yiwei &lt;quic_hyiwei@quicinc.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently ftrace only dumps the global trace buffer on an OOPs. For
debugging a production usecase, instance trace will be helpful to
check specific problems since global trace buffer may be used for
other purposes.

This patch extend the ftrace_dump_on_oops parameter to dump a specific
or multiple trace instances:

  - ftrace_dump_on_oops=0: as before -- don't dump
  - ftrace_dump_on_oops[=1]: as before -- dump the global trace buffer
  on all CPUs
  - ftrace_dump_on_oops=2 or =orig_cpu: as before -- dump the global
  trace buffer on CPU that triggered the oops
  - ftrace_dump_on_oops=&lt;instance_name&gt;: new behavior -- dump the
  tracing instance matching &lt;instance_name&gt;
  - ftrace_dump_on_oops[=2/orig_cpu],&lt;instance1_name&gt;[=2/orig_cpu],
  &lt;instrance2_name&gt;[=2/orig_cpu]: new behavior -- dump the global trace
  buffer and multiple instance buffer on all CPUs, or only dump on CPU
  that triggered the oops if =2 or =orig_cpu is given

Also, the sysctl node can handle the input accordingly.

Link: https://lore.kernel.org/linux-trace-kernel/20240223083126.1817731-1-quic_hyiwei@quicinc.com

Cc: Ross Zwisler &lt;zwisler@google.com&gt;
Cc: &lt;mhiramat@kernel.org&gt;
Cc: &lt;mark.rutland@arm.com&gt;
Cc: &lt;mcgrof@kernel.org&gt;
Cc: &lt;keescook@chromium.org&gt;
Cc: &lt;j.granados@samsung.com&gt;
Cc: &lt;mathieu.desnoyers@efficios.com&gt;
Cc: &lt;corbet@lwn.net&gt;
Signed-off-by: Huang Yiwei &lt;quic_hyiwei@quicinc.com&gt;
Signed-off-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-03-15T01:03:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-03-15T01:03:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e5eb28f6d1afebed4bb7d740a797d0390bd3a357'/>
<id>e5eb28f6d1afebed4bb7d740a797d0390bd3a357</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
   heap optimizations".

 - Kuan-Wei Chiu has also sped up the library sorting code in the series
   "lib/sort: Optimize the number of swaps and comparisons".

 - Alexey Gladkov has added the ability for code running within an IPC
   namespace to alter its IPC and MQ limits. The series is "Allow to
   change ipc/mq sysctls inside ipc namespace".

 - Geert Uytterhoeven has contributed some dhrystone maintenance work in
   the series "lib: dhry: miscellaneous cleanups".

 - Ryusuke Konishi continues nilfs2 maintenance work in the series

	"nilfs2: eliminate kmap and kmap_atomic calls"
	"nilfs2: fix kernel bug at submit_bh_wbc()"

 - Nathan Chancellor has updated our build tools requirements in the
   series "Bump the minimum supported version of LLVM to 13.0.1".

 - Muhammad Usama Anjum continues with the selftests maintenance work in
   the series "selftests/mm: Improve run_vmtests.sh".

 - Oleg Nesterov has done some maintenance work against the signal code
   in the series "get_signal: minor cleanups and fix".

Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.

* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  nilfs2: prevent kernel bug at submit_bh_wbc()
  nilfs2: fix failure to detect DAT corruption in btree and direct mappings
  ocfs2: enable ocfs2_listxattr for special files
  ocfs2: remove SLAB_MEM_SPREAD flag usage
  assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
  buildid: use kmap_local_page()
  watchdog/core: remove sysctl handlers from public header
  nilfs2: use div64_ul() instead of do_div()
  mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
  kexec: copy only happens before uchunk goes to zero
  get_signal: don't initialize ksig-&gt;info if SIGNAL_GROUP_EXIT/group_exec_task
  get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
  get_signal: don't abuse ksig-&gt;info.si_signo and ksig-&gt;sig
  const_structs.checkpatch: add device_type
  Normalise "name (ad@dr)" MODULE_AUTHORs to "name &lt;ad@dr&gt;"
  dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
  list: leverage list_is_head() for list_entry_is_head()
  nilfs2: MAINTAINERS: drop unreachable project mirror site
  smp: make __smp_processor_id() 0-argument macro
  fat: fix uninitialized field in nostale filehandles
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-MM updates from Andrew Morton:

 - Kuan-Wei Chiu has developed the well-named series "lib min_heap: Min
   heap optimizations".

 - Kuan-Wei Chiu has also sped up the library sorting code in the series
   "lib/sort: Optimize the number of swaps and comparisons".

 - Alexey Gladkov has added the ability for code running within an IPC
   namespace to alter its IPC and MQ limits. The series is "Allow to
   change ipc/mq sysctls inside ipc namespace".

 - Geert Uytterhoeven has contributed some dhrystone maintenance work in
   the series "lib: dhry: miscellaneous cleanups".

 - Ryusuke Konishi continues nilfs2 maintenance work in the series

	"nilfs2: eliminate kmap and kmap_atomic calls"
	"nilfs2: fix kernel bug at submit_bh_wbc()"

 - Nathan Chancellor has updated our build tools requirements in the
   series "Bump the minimum supported version of LLVM to 13.0.1".

 - Muhammad Usama Anjum continues with the selftests maintenance work in
   the series "selftests/mm: Improve run_vmtests.sh".

 - Oleg Nesterov has done some maintenance work against the signal code
   in the series "get_signal: minor cleanups and fix".

Plus the usual shower of singleton patches in various parts of the tree.
Please see the individual changelogs for details.

* tag 'mm-nonmm-stable-2024-03-14-09-36' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  nilfs2: prevent kernel bug at submit_bh_wbc()
  nilfs2: fix failure to detect DAT corruption in btree and direct mappings
  ocfs2: enable ocfs2_listxattr for special files
  ocfs2: remove SLAB_MEM_SPREAD flag usage
  assoc_array: fix the return value in assoc_array_insert_mid_shortcut()
  buildid: use kmap_local_page()
  watchdog/core: remove sysctl handlers from public header
  nilfs2: use div64_ul() instead of do_div()
  mul_u64_u64_div_u64: increase precision by conditionally swapping a and b
  kexec: copy only happens before uchunk goes to zero
  get_signal: don't initialize ksig-&gt;info if SIGNAL_GROUP_EXIT/group_exec_task
  get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
  get_signal: don't abuse ksig-&gt;info.si_signo and ksig-&gt;sig
  const_structs.checkpatch: add device_type
  Normalise "name (ad@dr)" MODULE_AUTHORs to "name &lt;ad@dr&gt;"
  dyndbg: replace kstrdup() + strchr() with kstrdup_and_replace()
  list: leverage list_is_head() for list_entry_is_head()
  nilfs2: MAINTAINERS: drop unreachable project mirror site
  smp: make __smp_processor_id() 0-argument macro
  fat: fix uninitialized field in nostale filehandles
  ...
</pre>
</div>
</content>
</entry>
</feed>
