<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/mm/util.c, branch v6.5</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>mm: uninline kstrdup()</title>
<updated>2023-04-08T20:45:37+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2023-02-28T15:34:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2a6772ebf05a9b6bc450e42bbb459f6327f68aca'/>
<id>2a6772ebf05a9b6bc450e42bbb459f6327f68aca</id>
<content type='text'>
gcc inlines kstrdup into kstrdup_const() but it can very efficiently tail
call into it instead:

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-84 (-84)
	Function                                     old     new   delta
	kstrdup_const                                119      35     -84

Link: https://lkml.kernel.org/r/Y/4fDlbIhTLNLFHz@p183
Signed-off-by: Alexey Dobriyan &lt;adobriyan@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>
gcc inlines kstrdup into kstrdup_const() but it can very efficiently tail
call into it instead:

	$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-84 (-84)
	Function                                     old     new   delta
	kstrdup_const                                119      35     -84

Link: https://lkml.kernel.org/r/Y/4fDlbIhTLNLFHz@p183
Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: fix typo in __vm_enough_memory warning</title>
<updated>2023-02-13T23:54:33+00:00</updated>
<author>
<name>Jakub Wilk</name>
<email>jwilk@jwilk.net</email>
</author>
<published>2023-02-10T20:33:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6bdfc60cf0f9771d592a006dcd2cf6e40e1ccd79'/>
<id>6bdfc60cf0f9771d592a006dcd2cf6e40e1ccd79</id>
<content type='text'>
Link: https://lkml.kernel.org/r/20230210203316.5613-1-jwilk@jwilk.net
Signed-off-by: Jakub Wilk &lt;jwilk@jwilk.net&gt;
Acked-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Cc: Kefeng Wang &lt;wangkefeng.wang@huawei.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>
Link: https://lkml.kernel.org/r/20230210203316.5613-1-jwilk@jwilk.net
Signed-off-by: Jakub Wilk &lt;jwilk@jwilk.net&gt;
Acked-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Cc: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: new primitive kvmemdup()</title>
<updated>2023-01-19T01:12:47+00:00</updated>
<author>
<name>Hao Sun</name>
<email>sunhao.th@gmail.com</email>
</author>
<published>2022-12-21T14:42:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0b7b8704ddcee372099a2bc6781db6ab273a85d5'/>
<id>0b7b8704ddcee372099a2bc6781db6ab273a85d5</id>
<content type='text'>
Similar to kmemdup(), but support large amount of bytes with kvmalloc()
and does *not* guarantee that the result will be physically contiguous. 
Use only in cases where kvmalloc() is needed and free it with kvfree(). 
Also adapt policy_unpack.c in case someone bisect into this.

Link: https://lkml.kernel.org/r/20221221144245.27164-1-sunhao.th@gmail.com
Signed-off-by: Hao Sun &lt;sunhao.th@gmail.com&gt;
Suggested-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Nick Terrell &lt;terrelln@fb.com&gt;
Cc: John Johansen &lt;john.johansen@canonical.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: "Serge E. Hallyn" &lt;serge@hallyn.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>
Similar to kmemdup(), but support large amount of bytes with kvmalloc()
and does *not* guarantee that the result will be physically contiguous. 
Use only in cases where kvmalloc() is needed and free it with kvfree(). 
Also adapt policy_unpack.c in case someone bisect into this.

Link: https://lkml.kernel.org/r/20221221144245.27164-1-sunhao.th@gmail.com
Signed-off-by: Hao Sun &lt;sunhao.th@gmail.com&gt;
Suggested-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Nick Terrell &lt;terrelln@fb.com&gt;
Cc: John Johansen &lt;john.johansen@canonical.com&gt;
Cc: Paul Moore &lt;paul@paul-moore.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Cc: "Serge E. Hallyn" &lt;serge@hallyn.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm,thp,rmap: simplify compound page mapcount handling</title>
<updated>2022-11-30T23:58:46+00:00</updated>
<author>
<name>Hugh Dickins</name>
<email>hughd@google.com</email>
</author>
<published>2022-11-03T01:51:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb67f4282bf9693658dbda934a441ddbbb1446df'/>
<id>cb67f4282bf9693658dbda934a441ddbbb1446df</id>
<content type='text'>
Compound page (folio) mapcount calculations have been different for anon
and file (or shmem) THPs, and involved the obscure PageDoubleMap flag. 
And each huge mapping and unmapping of a file (or shmem) THP involved
atomically incrementing and decrementing the mapcount of every subpage of
that huge page, dirtying many struct page cachelines.

Add subpages_mapcount field to the struct folio and first tail page, so
that the total of subpage mapcounts is available in one place near the
head: then page_mapcount() and total_mapcount() and page_mapped(), and
their folio equivalents, are so quick that anon and file and hugetlb don't
need to be optimized differently.  Delete the unloved PageDoubleMap.

page_add and page_remove rmap functions must now maintain the
subpages_mapcount as well as the subpage _mapcount, when dealing with pte
mappings of huge pages; and correct maintenance of NR_ANON_MAPPED and
NR_FILE_MAPPED statistics still needs reading through the subpages, using
nr_subpages_unmapped() - but only when first or last pmd mapping finds
subpages_mapcount raised (double-map case, not the common case).

But are those counts (used to decide when to split an anon THP, and in
vmscan's pagecache_reclaimable heuristic) correctly maintained?  Not
quite: since page_remove_rmap() (and also split_huge_pmd()) is often
called without page lock, there can be races when a subpage pte mapcount
0&lt;-&gt;1 while compound pmd mapcount 0&lt;-&gt;1 is scanning - races which the
previous implementation had prevented.  The statistics might become
inaccurate, and even drift down until they underflow through 0.  That is
not good enough, but is better dealt with in a followup patch.

Update a few comments on first and second tail page overlaid fields. 
hugepage_add_new_anon_rmap() has to "increment" compound_mapcount, but
subpages_mapcount and compound_pincount are already correctly at 0, so
delete its reinitialization of compound_pincount.

A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took
18 seconds on small pages, and used to take 1 second on huge pages, but
now takes 119 milliseconds on huge pages.  Mapping by pmds a second time
used to take 860ms and now takes 92ms; mapping by pmds after mapping by
ptes (when the scan is needed) used to take 870ms and now takes 495ms. 
But there might be some benchmarks which would show a slowdown, because
tail struct pages now fall out of cache until final freeing checks them.

Link: https://lkml.kernel.org/r/47ad693-717-79c8-e1ba-46c3a6602e48@google.com
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: James Houghton &lt;jthoughton@google.com&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Mina Almasry &lt;almasrymina@google.com&gt;
Cc: Muchun Song &lt;songmuchun@bytedance.com&gt;
Cc: Naoya Horiguchi &lt;naoya.horiguchi@linux.dev&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Sidhartha Kumar &lt;sidhartha.kumar@oracle.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Yang Shi &lt;shy828301@gmail.com&gt;
Cc: Zach O'Keefe &lt;zokeefe@google.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>
Compound page (folio) mapcount calculations have been different for anon
and file (or shmem) THPs, and involved the obscure PageDoubleMap flag. 
And each huge mapping and unmapping of a file (or shmem) THP involved
atomically incrementing and decrementing the mapcount of every subpage of
that huge page, dirtying many struct page cachelines.

Add subpages_mapcount field to the struct folio and first tail page, so
that the total of subpage mapcounts is available in one place near the
head: then page_mapcount() and total_mapcount() and page_mapped(), and
their folio equivalents, are so quick that anon and file and hugetlb don't
need to be optimized differently.  Delete the unloved PageDoubleMap.

page_add and page_remove rmap functions must now maintain the
subpages_mapcount as well as the subpage _mapcount, when dealing with pte
mappings of huge pages; and correct maintenance of NR_ANON_MAPPED and
NR_FILE_MAPPED statistics still needs reading through the subpages, using
nr_subpages_unmapped() - but only when first or last pmd mapping finds
subpages_mapcount raised (double-map case, not the common case).

But are those counts (used to decide when to split an anon THP, and in
vmscan's pagecache_reclaimable heuristic) correctly maintained?  Not
quite: since page_remove_rmap() (and also split_huge_pmd()) is often
called without page lock, there can be races when a subpage pte mapcount
0&lt;-&gt;1 while compound pmd mapcount 0&lt;-&gt;1 is scanning - races which the
previous implementation had prevented.  The statistics might become
inaccurate, and even drift down until they underflow through 0.  That is
not good enough, but is better dealt with in a followup patch.

Update a few comments on first and second tail page overlaid fields. 
hugepage_add_new_anon_rmap() has to "increment" compound_mapcount, but
subpages_mapcount and compound_pincount are already correctly at 0, so
delete its reinitialization of compound_pincount.

A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took
18 seconds on small pages, and used to take 1 second on huge pages, but
now takes 119 milliseconds on huge pages.  Mapping by pmds a second time
used to take 860ms and now takes 92ms; mapping by pmds after mapping by
ptes (when the scan is needed) used to take 870ms and now takes 495ms. 
But there might be some benchmarks which would show a slowdown, because
tail struct pages now fall out of cache until final freeing checks them.

Link: https://lkml.kernel.org/r/47ad693-717-79c8-e1ba-46c3a6602e48@google.com
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Acked-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: James Houghton &lt;jthoughton@google.com&gt;
Cc: John Hubbard &lt;jhubbard@nvidia.com&gt;
Cc: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Mina Almasry &lt;almasrymina@google.com&gt;
Cc: Muchun Song &lt;songmuchun@bytedance.com&gt;
Cc: Naoya Horiguchi &lt;naoya.horiguchi@linux.dev&gt;
Cc: Peter Xu &lt;peterx@redhat.com&gt;
Cc: Sidhartha Kumar &lt;sidhartha.kumar@oracle.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Yang Shi &lt;shy828301@gmail.com&gt;
Cc: Zach O'Keefe &lt;zokeefe@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2022-10-11T00:53:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-10-11T00:53:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=27bc50fc90647bbf7b734c3fc306a5e61350da53'/>
<id>27bc50fc90647bbf7b734c3fc306a5e61350da53</id>
<content type='text'>
Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP &amp; KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock-&gt;vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP &amp; KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock-&gt;vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: fix BUG splat with kvmalloc + GFP_ATOMIC</title>
<updated>2022-10-01T01:46:31+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2022-09-26T15:16:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=30c19366636f72515679aa10dad61a4d988d4c9a'/>
<id>30c19366636f72515679aa10dad61a4d988d4c9a</id>
<content type='text'>
Martin Zaharinov reports BUG with 5.19.10 kernel:
 kernel BUG at mm/vmalloc.c:2437!
 invalid opcode: 0000 [#1] SMP
 CPU: 28 PID: 0 Comm: swapper/28 Tainted: G        W  O      5.19.9 #1
 [..]
 RIP: 0010:__get_vm_area_node+0x120/0x130
  __vmalloc_node_range+0x96/0x1e0
  kvmalloc_node+0x92/0xb0
  bucket_table_alloc.isra.0+0x47/0x140
  rhashtable_try_insert+0x3a4/0x440
  rhashtable_insert_slow+0x1b/0x30
 [..]

bucket_table_alloc uses kvzalloc(GPF_ATOMIC).  If kmalloc fails, this now
falls through to vmalloc and hits code paths that assume GFP_KERNEL.

Link: https://lkml.kernel.org/r/20220926151650.15293-1-fw@strlen.de
Fixes: a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc")
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Suggested-by: Michal Hocko &lt;mhocko@suse.com&gt;
Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reported-by: Martin Zaharinov &lt;micron10@gmail.com&gt;
Cc: Uladzislau Rezki (Sony) &lt;urezki@gmail.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.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>
Martin Zaharinov reports BUG with 5.19.10 kernel:
 kernel BUG at mm/vmalloc.c:2437!
 invalid opcode: 0000 [#1] SMP
 CPU: 28 PID: 0 Comm: swapper/28 Tainted: G        W  O      5.19.9 #1
 [..]
 RIP: 0010:__get_vm_area_node+0x120/0x130
  __vmalloc_node_range+0x96/0x1e0
  kvmalloc_node+0x92/0xb0
  bucket_table_alloc.isra.0+0x47/0x140
  rhashtable_try_insert+0x3a4/0x440
  rhashtable_insert_slow+0x1b/0x30
 [..]

bucket_table_alloc uses kvzalloc(GPF_ATOMIC).  If kmalloc fails, this now
falls through to vmalloc and hits code paths that assume GFP_KERNEL.

Link: https://lkml.kernel.org/r/20220926151650.15293-1-fw@strlen.de
Fixes: a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc")
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Suggested-by: Michal Hocko &lt;mhocko@suse.com&gt;
Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reported-by: Martin Zaharinov &lt;micron10@gmail.com&gt;
Cc: Uladzislau Rezki (Sony) &lt;urezki@gmail.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: remove the vma linked list</title>
<updated>2022-09-27T02:46:26+00:00</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@Oracle.com</email>
</author>
<published>2022-09-06T19:49:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=763ecb035029f500d7e6dc99acd1ad299b7726a1'/>
<id>763ecb035029f500d7e6dc99acd1ad299b7726a1</id>
<content type='text'>
Replace any vm_next use with vma_find().

Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.

Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap().  At
the same time, alter the loop to be more compact.

Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.

Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list.

Drop linked list update from __insert_vm_struct().

Rework validation of tree as it was depending on the linked list.

[yang.lee@linux.alibaba.com: fix one kernel-doc comment]
  Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=1949
  Link: https://lkml.kernel.org/r/20220824021918.94116-1-yang.lee@linux.alibaba.comLink: https://lkml.kernel.org/r/20220906194824.2110408-69-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Will Deacon &lt;will@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>
Replace any vm_next use with vma_find().

Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.

Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap().  At
the same time, alter the loop to be more compact.

Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.

Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list.

Drop linked list update from __insert_vm_struct().

Rework validation of tree as it was depending on the linked list.

[yang.lee@linux.alibaba.com: fix one kernel-doc comment]
  Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=1949
  Link: https://lkml.kernel.org/r/20220824021918.94116-1-yang.lee@linux.alibaba.comLink: https://lkml.kernel.org/r/20220906194824.2110408-69-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Signed-off-by: Yang Li &lt;yang.lee@linux.alibaba.com&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: remove rb tree.</title>
<updated>2022-09-27T02:46:16+00:00</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@Oracle.com</email>
</author>
<published>2022-09-06T19:48:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=524e00b36e8c547f5582eef3fb645a8d9fc5e3df'/>
<id>524e00b36e8c547f5582eef3fb645a8d9fc5e3df</id>
<content type='text'>
Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Will Deacon &lt;will@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>
Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: "Matthew Wilcox (Oracle)" &lt;willy@infradead.org&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/util.c: add warning if __vm_enough_memory fails</title>
<updated>2022-09-12T03:25:54+00:00</updated>
<author>
<name>Kefeng Wang</name>
<email>wangkefeng.wang@huawei.com</email>
</author>
<published>2022-07-26T14:54:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=44b414c8715c5dcf53288ce9005d7b24cc90eaf5'/>
<id>44b414c8715c5dcf53288ce9005d7b24cc90eaf5</id>
<content type='text'>
If a process has not enough memory to allocate a new virtual mapping, we
may meet verious kinds of error, eg, fork cannot allocate memory, SIGBUS
error in shmem, but it is difficult to confirm them, let's add some debug
information to easily to check this scenario if __vm_enough_memory fails.

Link: https://lkml.kernel.org/r/20220726145428.8030-1-wangkefeng.wang@huawei.com
Reported-by: Yongqiang Liu &lt;liuyongqiang13@huawei.com&gt;
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.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>
If a process has not enough memory to allocate a new virtual mapping, we
may meet verious kinds of error, eg, fork cannot allocate memory, SIGBUS
error in shmem, but it is difficult to confirm them, let's add some debug
information to easily to check this scenario if __vm_enough_memory fails.

Link: https://lkml.kernel.org/r/20220726145428.8030-1-wangkefeng.wang@huawei.com
Reported-by: Yongqiang Liu &lt;liuyongqiang13@huawei.com&gt;
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm/util: reduce stack usage of folio_mapcount</title>
<updated>2022-09-12T03:25:51+00:00</updated>
<author>
<name>Kairui Song</name>
<email>kasong@tencent.com</email>
</author>
<published>2022-08-01T17:31:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2fd86a07c9ac50dfbc5eef3c69ef6e5d370f3b28'/>
<id>2fd86a07c9ac50dfbc5eef3c69ef6e5d370f3b28</id>
<content type='text'>
folio_test_hugetlb() will call PageHeadHuge which is a function call,
and blocks the compiler from recognizing this redundant load.

After rearranging the code, stack usage is dropped from 32 to 24, and
the function size is smaller (tested on GCC 12):

Before:
Stack usage:
mm/util.c:845:5:folio_mapcount  32      static
Size:
0000000000000ea0 00000000000000c7 T folio_mapcount

After:
Stack usage:
mm/util.c:845:5:folio_mapcount  24      static
Size:
0000000000000ea0 00000000000000b0 T folio_mapcount

Link: https://lkml.kernel.org/r/20220801173155.92008-1-ryncsn@gmail.com
Signed-off-by: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.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>
folio_test_hugetlb() will call PageHeadHuge which is a function call,
and blocks the compiler from recognizing this redundant load.

After rearranging the code, stack usage is dropped from 32 to 24, and
the function size is smaller (tested on GCC 12):

Before:
Stack usage:
mm/util.c:845:5:folio_mapcount  32      static
Size:
0000000000000ea0 00000000000000c7 T folio_mapcount

After:
Stack usage:
mm/util.c:845:5:folio_mapcount  24      static
Size:
0000000000000ea0 00000000000000b0 T folio_mapcount

Link: https://lkml.kernel.org/r/20220801173155.92008-1-ryncsn@gmail.com
Signed-off-by: Kairui Song &lt;kasong@tencent.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
