linux.git/mm/internal.h, branch v6.0 Linux kernel source tree Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2022-08-05T23:32:45+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-08-05T23:32:45+00:00 6614a3c3164a5df2b54abb0b3559f51041cf705b Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ... 
Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
mm/mprotect: fix soft-dirty check in can_change_pte_writable() 2022-07-30T01:07:18+00:00 Peter Xu peterx@redhat.com 2022-07-25T14:20:46+00:00 76aefad628aae152207ee624a7981b9aa1a267d8 Patch series "mm/mprotect: Fix soft-dirty checks", v4. This patch (of 3): The check wanted to make sure when soft-dirty tracking is enabled we won't grant write bit by accident, as a page fault is needed for dirty tracking. The intention is correct but we didn't check it right because VM_SOFTDIRTY set actually means soft-dirty tracking disabled. Fix it. There's another thing tricky about soft-dirty is that, we can't check the vma flag !(vma_flags & VM_SOFTDIRTY) directly but only check it after we checked CONFIG_MEM_SOFT_DIRTY because otherwise VM_SOFTDIRTY will be defined as zero, and !(vma_flags & VM_SOFTDIRTY) will constantly return true. To avoid misuse, introduce a helper for checking whether vma has soft-dirty tracking enabled. We can easily verify this with any exclusive anonymous page, like program below: =======8<====== #include <stdio.h> #include <unistd.h> #include <stdlib.h> #include <assert.h> #include <inttypes.h> #include <stdint.h> #include <sys/types.h> #include <sys/mman.h> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <fcntl.h> #include <stdbool.h> #define BIT_ULL(nr) (1ULL << (nr)) #define PM_SOFT_DIRTY BIT_ULL(55) unsigned int psize; char *page; uint64_t pagemap_read_vaddr(int fd, void *vaddr) { uint64_t value; int ret; ret = pread(fd, &value, sizeof(uint64_t), ((uint64_t)vaddr >> 12) * sizeof(uint64_t)); assert(ret == sizeof(uint64_t)); return value; } void clear_refs_write(void) { int fd = open("/proc/self/clear_refs", O_RDWR); assert(fd >= 0); write(fd, "4", 2); close(fd); } #define check_soft_dirty(str, expect) do { \ bool dirty = pagemap_read_vaddr(fd, page) & PM_SOFT_DIRTY; \ if (dirty != expect) { \ printf("ERROR: %s, soft-dirty=%d (expect: %d) ", str, dirty, expect); \ exit(-1); \ } \ } while (0) int main(void) { int fd = open("/proc/self/pagemap", O_RDONLY); assert(fd >= 0); psize = getpagesize(); page = mmap(NULL, psize, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); assert(page != MAP_FAILED); *page = 1; check_soft_dirty("Just faulted in page", 1); clear_refs_write(); check_soft_dirty("Clear_refs written", 0); mprotect(page, psize, PROT_READ); check_soft_dirty("Marked RO", 0); mprotect(page, psize, PROT_READ|PROT_WRITE); check_soft_dirty("Marked RW", 0); *page = 2; check_soft_dirty("Wrote page again", 1); munmap(page, psize); close(fd); printf("Test passed. "); return 0; } =======8<====== Here we attach a Fixes to commit 64fe24a3e05e only for easy tracking, as this patch won't apply to a tree before that point. However the commit wasn't the source of problem, but instead 64e455079e1b. It's just that after 64fe24a3e05e anonymous memory will also suffer from this problem with mprotect(). Link: https://lkml.kernel.org/r/20220725142048.30450-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20220725142048.30450-2-peterx@redhat.com Fixes: 64e455079e1b ("mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared") Fixes: 64fe24a3e05e ("mm/mprotect: try avoiding write faults for exclusive anonymous pages when changing protection") Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Patch series "mm/mprotect: Fix soft-dirty checks", v4.


This patch (of 3):

The check wanted to make sure when soft-dirty tracking is enabled we won't
grant write bit by accident, as a page fault is needed for dirty tracking.
The intention is correct but we didn't check it right because
VM_SOFTDIRTY set actually means soft-dirty tracking disabled.  Fix it.

There's another thing tricky about soft-dirty is that, we can't check the
vma flag !(vma_flags & VM_SOFTDIRTY) directly but only check it after we
checked CONFIG_MEM_SOFT_DIRTY because otherwise VM_SOFTDIRTY will be
defined as zero, and !(vma_flags & VM_SOFTDIRTY) will constantly return
true.  To avoid misuse, introduce a helper for checking whether vma has
soft-dirty tracking enabled.

We can easily verify this with any exclusive anonymous page, like program
below:

=======8<======
  #include <stdio.h>
  #include <unistd.h>
  #include <stdlib.h>
  #include <assert.h>
  #include <inttypes.h>
  #include <stdint.h>
  #include <sys/types.h>
  #include <sys/mman.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <stdbool.h>

  #define BIT_ULL(nr)                   (1ULL << (nr))
  #define PM_SOFT_DIRTY                 BIT_ULL(55)

  unsigned int psize;
  char *page;

  uint64_t pagemap_read_vaddr(int fd, void *vaddr)
  {
      uint64_t value;
      int ret;

      ret = pread(fd, &value, sizeof(uint64_t),
                  ((uint64_t)vaddr >> 12) * sizeof(uint64_t));
      assert(ret == sizeof(uint64_t));

      return value;
  }

  void clear_refs_write(void)
  {
      int fd = open("/proc/self/clear_refs", O_RDWR);

      assert(fd >= 0);
      write(fd, "4", 2);
      close(fd);
  }

  #define  check_soft_dirty(str, expect)  do {                            \
          bool dirty = pagemap_read_vaddr(fd, page) & PM_SOFT_DIRTY;      \
          if (dirty != expect) {                                          \
              printf("ERROR: %s, soft-dirty=%d (expect: %d)
", str, dirty, expect); \
              exit(-1);                                                   \
          }                                                               \
  } while (0)

  int main(void)
  {
      int fd = open("/proc/self/pagemap", O_RDONLY);

      assert(fd >= 0);
      psize = getpagesize();
      page = mmap(NULL, psize, PROT_READ|PROT_WRITE,
                  MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
      assert(page != MAP_FAILED);

      *page = 1;
      check_soft_dirty("Just faulted in page", 1);
      clear_refs_write();
      check_soft_dirty("Clear_refs written", 0);
      mprotect(page, psize, PROT_READ);
      check_soft_dirty("Marked RO", 0);
      mprotect(page, psize, PROT_READ|PROT_WRITE);
      check_soft_dirty("Marked RW", 0);
      *page = 2;
      check_soft_dirty("Wrote page again", 1);

      munmap(page, psize);
      close(fd);
      printf("Test passed.
");

      return 0;
  }
=======8<======

Here we attach a Fixes to commit 64fe24a3e05e only for easy tracking, as
this patch won't apply to a tree before that point.  However the commit
wasn't the source of problem, but instead 64e455079e1b.  It's just that
after 64fe24a3e05e anonymous memory will also suffer from this problem
with mprotect().

Link: https://lkml.kernel.org/r/20220725142048.30450-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20220725142048.30450-2-peterx@redhat.com
Fixes: 64e455079e1b ("mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared")
Fixes: 64fe24a3e05e ("mm/mprotect: try avoiding write faults for exclusive anonymous pages when changing protection")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/gup: migrate device coherent pages when pinning instead of failing 2022-07-18T00:14:28+00:00 Alistair Popple apopple@nvidia.com 2022-07-15T15:05:13+00:00 b05a79d4377f6dcc30683008ffd1c531ea965393 Currently any attempts to pin a device coherent page will fail. This is because device coherent pages need to be managed by a device driver, and pinning them would prevent a driver from migrating them off the device. However this is no reason to fail pinning of these pages. These are coherent and accessible from the CPU so can be migrated just like pinning ZONE_MOVABLE pages. So instead of failing all attempts to pin them first try migrating them out of ZONE_DEVICE. [hch@lst.de: rebased to the split device memory checks, moved migrate_device_page to migrate_device.c] Link: https://lkml.kernel.org/r/20220715150521.18165-7-alex.sierra@amd.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Felix Kuehling <Felix.Kuehling@amd.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Currently any attempts to pin a device coherent page will fail.  This is
because device coherent pages need to be managed by a device driver, and
pinning them would prevent a driver from migrating them off the device.

However this is no reason to fail pinning of these pages.  These are
coherent and accessible from the CPU so can be migrated just like pinning
ZONE_MOVABLE pages.  So instead of failing all attempts to pin them first
try migrating them out of ZONE_DEVICE.

[hch@lst.de: rebased to the split device memory checks, moved migrate_device_page to migrate_device.c]
Link: https://lkml.kernel.org/r/20220715150521.18165-7-alex.sierra@amd.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
memblock: Disable mirror feature if kernelcore is not specified 2022-06-15T10:14:33+00:00 Ma Wupeng mawupeng1@huawei.com 2022-06-14T09:21:56+00:00 902c2d91582c7ff0cb5f57ffb3766656f9b910c6 If system have some mirrored memory and mirrored feature is not specified in boot parameter, the basic mirrored feature will be enabled and this will lead to the following situations: - memblock memory allocation prefers mirrored region. This may have some unexpected influence on numa affinity. - contiguous memory will be split into several parts if parts of them is mirrored memory via memblock_mark_mirror(). To fix this, variable mirrored_kernelcore will be checked in memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff kernelcore=mirror is added in the kernel parameters. Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220614092156.1972846-6-mawupeng1@huawei.com Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
If system have some mirrored memory and mirrored feature is not specified
in boot parameter, the basic mirrored feature will be enabled and this will
lead to the following situations:

- memblock memory allocation prefers mirrored region. This may have some
  unexpected influence on numa affinity.

- contiguous memory will be split into several parts if parts of them
  is mirrored memory via memblock_mark_mirror().

To fix this, variable mirrored_kernelcore will be checked in
memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
kernelcore=mirror is added in the kernel parameters.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20220614092156.1972846-6-mawupeng1@huawei.com
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
mm: split free page with properly free memory accounting and without race 2022-05-27T16:33:43+00:00 Zi Yan ziy@nvidia.com 2022-05-26T23:15:31+00:00 86d28b0709279ccc636ef9ba267b7f3bcef79a4b In isolate_single_pageblock(), free pages are checked without holding zone lock, but they can go away in split_free_page() when zone lock is held. Check the free page and its order again in split_free_page() when zone lock is held. Recheck the page if the free page is gone under zone lock. In addition, in split_free_page(), the free page was deleted from the page list without changing free page accounting. Add the missing free page accounting code. Fix the type of order parameter in split_free_page(). Link: https://lore.kernel.org/lkml/20220525103621.987185e2ca0079f7b97b856d@linux-foundation.org/ Link: https://lkml.kernel.org/r/20220526231531.2404977-2-zi.yan@sent.com Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity") Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: Doug Berger <opendmb@gmail.com> Link: https://lore.kernel.org/linux-mm/c3932a6f-77fe-29f7-0c29-fe6b1c67ab7b@gmail.com/ Cc: David Hildenbrand <david@redhat.com> Cc: Qian Cai <quic_qiancai@quicinc.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michael Walle <michael@walle.cc> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
In isolate_single_pageblock(), free pages are checked without holding zone
lock, but they can go away in split_free_page() when zone lock is held.
Check the free page and its order again in split_free_page() when zone lock
is held. Recheck the page if the free page is gone under zone lock.

In addition, in split_free_page(), the free page was deleted from the page
list without changing free page accounting. Add the missing free page
accounting code.

Fix the type of order parameter in split_free_page().

Link: https://lore.kernel.org/lkml/20220525103621.987185e2ca0079f7b97b856d@linux-foundation.org/
Link: https://lkml.kernel.org/r/20220526231531.2404977-2-zi.yan@sent.com
Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: Doug Berger <opendmb@gmail.com>
  Link: https://lore.kernel.org/linux-mm/c3932a6f-77fe-29f7-0c29-fe6b1c67ab7b@gmail.com/
Cc: David Hildenbrand <david@redhat.com>
Cc: Qian Cai <quic_qiancai@quicinc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Eric Ren <renzhengeek@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michael Walle <michael@walle.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: fix missing handler for __GFP_NOWARN 2022-05-19T21:08:55+00:00 Qi Zheng zhengqi.arch@bytedance.com 2022-05-19T21:08:55+00:00 3f913fc5f9745613088d3c569778c9813ab9c129 We expect no warnings to be issued when we specify __GFP_NOWARN, but currently in paths like alloc_pages() and kmalloc(), there are still some warnings printed, fix it. But for some warnings that report usage problems, we don't deal with them. If such warnings are printed, then we should fix the usage problems. Such as the following case: WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); [zhengqi.arch@bytedance.com: v2] Link: https://lkml.kernel.org/r/20220511061951.1114-1-zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/20220510113809.80626-1-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
We expect no warnings to be issued when we specify __GFP_NOWARN, but
currently in paths like alloc_pages() and kmalloc(), there are still some
warnings printed, fix it.

But for some warnings that report usage problems, we don't deal with them.
If such warnings are printed, then we should fix the usage problems. 
Such as the following case:

	WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));

[zhengqi.arch@bytedance.com: v2]
 Link: https://lkml.kernel.org/r/20220511061951.1114-1-zhengqi.arch@bytedance.com
Link: https://lkml.kernel.org/r/20220510113809.80626-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/memory-failure.c: move clear_hwpoisoned_pages 2022-05-13T14:20:19+00:00 zhenwei pi pizhenwei@bytedance.com 2022-05-13T03:23:09+00:00 60f272f6b09a8f14156df88cccd21447ab394452 Patch series "memory-failure: fix hwpoison_filter", v2. As well known, the memory failure mechanism handles memory corrupted event, and try to send SIGBUS to the user process which uses this corrupted page. For the virtualization case, QEMU catches SIGBUS and tries to inject MCE into the guest, and the guest handles memory failure again. Thus the guest gets the minimal effect from hardware memory corruption. The further step I'm working on: 1, try to modify code to decrease poisoned pages in a single place (mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series). 2, try to use page_handle_poison() to handle SetPageHWPoison() and num_poisoned_pages_inc() together. It would be best to call num_poisoned_pages_inc() in a single place too. 3, introduce memory failure notifier list in memory-failure.c: notify the corrupted PFN to someone who registers this list. If I can complete [1] and [2] part, [3] will be quite easy(just call notifier list after increasing poisoned page). 4, introduce memory recover VQ for memory balloon device, and registers memory failure notifier list. During the guest kernel handles memory failure, balloon device gets notified by memory failure notifier list, and tells the host to recover the corrupted PFN(GPA) by the new VQ. 5, host side remaps the corrupted page(HVA), and tells the guest side to unpoison the PFN(GPA). Then the guest fixes the corrupted page(GPA) dynamically. This patch (of 5): clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of poisoned pages, this actually works as part of memory failure. Move this function from sparse.c to memory-failure.c, finally there is no CONFIG_MEMORY_FAILURE in sparse.c. Link: https://lkml.kernel.org/r/20220509105641.491313-1-pizhenwei@bytedance.com Link: https://lkml.kernel.org/r/20220509105641.491313-2-pizhenwei@bytedance.com Signed-off-by: zhenwei pi <pizhenwei@bytedance.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Patch series "memory-failure: fix hwpoison_filter", v2.

As well known, the memory failure mechanism handles memory corrupted
event, and try to send SIGBUS to the user process which uses this
corrupted page.

For the virtualization case, QEMU catches SIGBUS and tries to inject MCE
into the guest, and the guest handles memory failure again.  Thus the
guest gets the minimal effect from hardware memory corruption.

The further step I'm working on:

1, try to modify code to decrease poisoned pages in a single place
   (mm/memofy-failure.c: simplify num_poisoned_pages_dec in this series).

2, try to use page_handle_poison() to handle SetPageHWPoison() and
   num_poisoned_pages_inc() together.  It would be best to call
   num_poisoned_pages_inc() in a single place too.

3, introduce memory failure notifier list in memory-failure.c: notify
   the corrupted PFN to someone who registers this list.  If I can
   complete [1] and [2] part, [3] will be quite easy(just call notifier
   list after increasing poisoned page).

4, introduce memory recover VQ for memory balloon device, and registers
   memory failure notifier list.  During the guest kernel handles memory
   failure, balloon device gets notified by memory failure notifier list,
   and tells the host to recover the corrupted PFN(GPA) by the new VQ.

5, host side remaps the corrupted page(HVA), and tells the guest side
   to unpoison the PFN(GPA).  Then the guest fixes the corrupted page(GPA)
   dynamically.


This patch (of 5):

clear_hwpoisoned_pages() clears HWPoison flag and decreases the number of
poisoned pages, this actually works as part of memory failure.

Move this function from sparse.c to memory-failure.c, finally there is no
CONFIG_MEMORY_FAILURE in sparse.c.

Link: https://lkml.kernel.org/r/20220509105641.491313-1-pizhenwei@bytedance.com
Link: https://lkml.kernel.org/r/20220509105641.491313-2-pizhenwei@bytedance.com
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: make alloc_contig_range work at pageblock granularity 2022-05-13T14:20:13+00:00 Zi Yan ziy@nvidia.com 2022-05-13T03:22:58+00:00 b2c9e2fbba32539626522b6aed30d1dde7b7e971 alloc_contig_range() worked at MAX_ORDER_NR_PAGES granularity to avoid merging pageblocks with different migratetypes. It might unnecessarily convert extra pageblocks at the beginning and at the end of the range. Change alloc_contig_range() to work at pageblock granularity. Special handling is needed for free pages and in-use pages across the boundaries of the range specified by alloc_contig_range(). Because these= Partially isolated pages causes free page accounting issues. The free pages will be split and freed into separate migratetype lists; the in-use= Pages will be migrated then the freed pages will be handled in the aforementioned way. [ziy@nvidia.com: fix deadlock/crash] Link: https://lkml.kernel.org/r/23A7297E-6C84-4138-A9FE-3598234004E6@nvidia.com Link: https://lkml.kernel.org/r/20220425143118.2850746-4-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: kernel test robot <lkp@intel.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
alloc_contig_range() worked at MAX_ORDER_NR_PAGES granularity to avoid
merging pageblocks with different migratetypes.  It might unnecessarily
convert extra pageblocks at the beginning and at the end of the range. 
Change alloc_contig_range() to work at pageblock granularity.

Special handling is needed for free pages and in-use pages across the
boundaries of the range specified by alloc_contig_range().  Because these=

Partially isolated pages causes free page accounting issues.  The free
pages will be split and freed into separate migratetype lists; the in-use=

Pages will be migrated then the freed pages will be handled in the
aforementioned way.

[ziy@nvidia.com: fix deadlock/crash]
  Link: https://lkml.kernel.org/r/23A7297E-6C84-4138-A9FE-3598234004E6@nvidia.com
Link: https://lkml.kernel.org/r/20220425143118.2850746-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Ren <renzhengeek@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: compaction: clean up comment for sched contention 2022-04-29T06:16:17+00:00 Miaohe Lin linmiaohe@huawei.com 2022-04-29T06:16:17+00:00 d56c15845a5493dbe9e8b77f63418bea117d1221 Since commit cf66f0700c8f ("mm, compaction: do not consider a need to reschedule as contention"), async compaction won't abort when scheduling is needed. Correct the relevant comment accordingly. Link: https://lkml.kernel.org/r/20220418141253.24298-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Charan Teja Kalla <charante@codeaurora.org> Cc: David Hildenbrand <david@redhat.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Since commit cf66f0700c8f ("mm, compaction: do not consider a need to
reschedule as contention"), async compaction won't abort when scheduling
is needed.  Correct the relevant comment accordingly.

Link: https://lkml.kernel.org/r/20220418141253.24298-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Charan Teja Kalla <charante@codeaurora.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pintu Kumar <pintu@codeaurora.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: rmap: introduce pfn_mkclean_range() to cleans PTEs 2022-04-29T06:16:10+00:00 Muchun Song songmuchun@bytedance.com 2022-04-29T06:16:10+00:00 6a8e0596f00469c15ec556b9f3624acd2e9a04f9 The page_mkclean_one() is supposed to be used with the pfn that has a associated struct page, but not all the pfns (e.g. DAX) have a struct page. Introduce a new function pfn_mkclean_range() to cleans the PTEs (including PMDs) mapped with range of pfns which has no struct page associated with them. This helper will be used by DAX device in the next patch to make pfns clean. Link: https://lkml.kernel.org/r/20220403053957.10770-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The page_mkclean_one() is supposed to be used with the pfn that has a
associated struct page, but not all the pfns (e.g.  DAX) have a struct
page.  Introduce a new function pfn_mkclean_range() to cleans the PTEs
(including PMDs) mapped with range of pfns which has no struct page
associated with them.  This helper will be used by DAX device in the next
patch to make pfns clean.

Link: https://lkml.kernel.org/r/20220403053957.10770-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>