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* + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree
@ 2020-06-24 19:19 akpm
  0 siblings, 0 replies; 4+ messages in thread
From: akpm @ 2020-06-24 19:19 UTC (permalink / raw)
  To: mm-commits, zeil, tony.luck, osalvador, mike.kravetz, mhocko,
	david, dave.hansen, aneesh.kumar, aneesh.kumar, naoya.horiguchi


The patch titled
     Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED
has been added to the -mm tree.  Its filename is
     mmmadvise-call-soft_offline_page-without-mf_count_increased.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED

The call to get_user_pages_fast is only to get the pointer to a struct
page of a given address, pinning it is memory-poisoning handler's job, so
drop the refcount grabbed by get_user_pages_fast().

Note that the target page is still pinned after this put_page() because
the current process should have refcount from mapping.

Link: http://lkml.kernel.org/r/20200624150137.7052-4-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/madvise.c |   24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

--- a/mm/madvise.c~mmmadvise-call-soft_offline_page-without-mf_count_increased
+++ a/mm/madvise.c
@@ -893,16 +893,24 @@ static int madvise_inject_error(int beha
 		 */
 		size = page_size(compound_head(page));
 
-		if (PageHWPoison(page)) {
-			put_page(page);
+		/*
+		 * The get_user_pages_fast() is just to get the pfn of the
+		 * given address, and the refcount has nothing to do with
+		 * what we try to test, so it should be released immediately.
+		 * This is racy but it's intended because the real hardware
+		 * errors could happen at any moment and memory error handlers
+		 * must properly handle the race.
+		 */
+		put_page(page);
+
+		if (PageHWPoison(page))
 			continue;
-		}
 
 		if (behavior == MADV_SOFT_OFFLINE) {
 			pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
 					pfn, start);
 
-			ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
+			ret = soft_offline_page(pfn, 0);
 			if (ret)
 				return ret;
 			continue;
@@ -910,14 +918,6 @@ static int madvise_inject_error(int beha
 
 		pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n",
 				pfn, start);

^ permalink raw reply	[flat|nested] 4+ messages in thread
* incoming
@ 2020-07-03 22:14 Andrew Morton
  2020-07-16 21:45 ` + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree Andrew Morton
  0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2020-07-03 22:14 UTC (permalink / raw)
  To: Linus Torvalds; +Cc: mm-commits, linux-mm

5 patches, based on cdd3bb54332f82295ed90cd0c09c78cd0c0ee822.

Subsystems affected by this patch series:

  mm/hugetlb
  samples
  mm/cma
  mm/vmalloc
  mm/pagealloc

Subsystem: mm/hugetlb

    Mike Kravetz <mike.kravetz@oracle.com>:
      mm/hugetlb.c: fix pages per hugetlb calculation

Subsystem: samples

    Kees Cook <keescook@chromium.org>:
      samples/vfs: avoid warning in statx override

Subsystem: mm/cma

    Barry Song <song.bao.hua@hisilicon.com>:
      mm/cma.c: use exact_nid true to fix possible per-numa cma leak

Subsystem: mm/vmalloc

    Christoph Hellwig <hch@lst.de>:
      vmalloc: fix the owner argument for the new __vmalloc_node_range callers

Subsystem: mm/pagealloc

    Joel Savitz <jsavitz@redhat.com>:
      mm/page_alloc: fix documentation error

 arch/arm64/kernel/probes/kprobes.c |    2 +-
 arch/x86/hyperv/hv_init.c          |    3 ++-
 kernel/module.c                    |    2 +-
 mm/cma.c                           |    4 ++--
 mm/hugetlb.c                       |    2 +-
 mm/page_alloc.c                    |    2 +-
 samples/vfs/test-statx.c           |    2 ++
 7 files changed, 10 insertions(+), 7 deletions(-)

^ permalink raw reply	[flat|nested] 4+ messages in thread
* incoming
@ 2020-07-24  4:14 Andrew Morton
  2020-07-31 20:05 ` + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree Andrew Morton
  0 siblings, 1 reply; 4+ messages in thread
From: Andrew Morton @ 2020-07-24  4:14 UTC (permalink / raw)
  To: Linus Torvalds; +Cc: mm-commits, linux-mm


15 patches, based on f37e99aca03f63aa3f2bd13ceaf769455d12c4b0.

Subsystems affected by this patch series:

  mm/pagemap
  mm/shmem
  mm/hotfixes
  mm/memcg
  mm/hugetlb
  mailmap
  squashfs
  scripts
  io-mapping
  MAINTAINERS
  gdb

Subsystem: mm/pagemap

    Yang Shi <yang.shi@linux.alibaba.com>:
      mm/memory.c: avoid access flag update TLB flush for retried page fault

    "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>:
      mm/mmap.c: close race between munmap() and expand_upwards()/downwards()

Subsystem: mm/shmem

    Chengguang Xu <cgxu519@mykernel.net>:
      vfs/xattr: mm/shmem: kernfs: release simple xattr entry in a right way

Subsystem: mm/hotfixes

    Tom Rix <trix@redhat.com>:
      mm: initialize return of vm_insert_pages

    Bhupesh Sharma <bhsharma@redhat.com>:
      mm/memcontrol: fix OOPS inside mem_cgroup_get_nr_swap_pages()

Subsystem: mm/memcg

    Hugh Dickins <hughd@google.com>:
      mm/memcg: fix refcount error while moving and swapping

    Muchun Song <songmuchun@bytedance.com>:
      mm: memcg/slab: fix memory leak at non-root kmem_cache destroy

Subsystem: mm/hugetlb

    Barry Song <song.bao.hua@hisilicon.com>:
      mm/hugetlb: avoid hardcoding while checking if cma is enabled

    "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>:
      khugepaged: fix null-pointer dereference due to race

Subsystem: mailmap

    Mike Rapoport <rppt@linux.ibm.com>:
      mailmap: add entry for Mike Rapoport

Subsystem: squashfs

    Phillip Lougher <phillip@squashfs.org.uk>:
      squashfs: fix length field overlap check in metadata reading

Subsystem: scripts

    Pi-Hsun Shih <pihsun@chromium.org>:
      scripts/decode_stacktrace: strip basepath from all paths

Subsystem: io-mapping

    "Michael J. Ruhl" <michael.j.ruhl@intel.com>:
      io-mapping: indicate mapping failure

Subsystem: MAINTAINERS

    Andrey Konovalov <andreyknvl@google.com>:
      MAINTAINERS: add KCOV section

Subsystem: gdb

    Stefano Garzarella <sgarzare@redhat.com>:
      scripts/gdb: fix lx-symbols 'gdb.error' while loading modules

 .mailmap                     |    3 +++
 MAINTAINERS                  |   11 +++++++++++
 fs/squashfs/block.c          |    2 +-
 include/linux/io-mapping.h   |    5 ++++-
 include/linux/xattr.h        |    3 ++-
 mm/hugetlb.c                 |   15 ++++++++++-----
 mm/khugepaged.c              |    3 +++
 mm/memcontrol.c              |   13 ++++++++++---
 mm/memory.c                  |    9 +++++++--
 mm/mmap.c                    |   16 ++++++++++++++--
 mm/shmem.c                   |    2 +-
 mm/slab_common.c             |   35 ++++++++++++++++++++++++++++-------
 scripts/decode_stacktrace.sh |    4 ++--
 scripts/gdb/linux/symbols.py |    2 +-
 14 files changed, 97 insertions(+), 26 deletions(-)


^ permalink raw reply	[flat|nested] 4+ messages in thread
* + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree
@ 2020-11-20 23:58 akpm
  0 siblings, 0 replies; 4+ messages in thread
From: akpm @ 2020-11-20 23:58 UTC (permalink / raw)
  To: mm-commits, naoya.horiguchi, osalvador


The patch titled
     Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED
has been added to the -mm tree.  Its filename is
     mmmadvise-call-soft_offline_page-without-mf_count_increased.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mmmadvise-call-soft_offline_page-without-mf_count_increased.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@nec.com>
Subject: mm,madvise: call soft_offline_page() without MF_COUNT_INCREASED

The call to get_user_pages_fast is only to get the pointer to a struct
page of a given address, pinning it is memory-poisoning handler's job, so
drop the refcount grabbed by get_user_pages_fast().

Note that the target page is still pinned after this put_page() because
the current process should have refcount from mapping.

Link: https://lkml.kernel.org/r/20201119105716.5962-4-osalvador@suse.de
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/madvise.c |   19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

--- a/mm/madvise.c~mmmadvise-call-soft_offline_page-without-mf_count_increased
+++ a/mm/madvise.c
@@ -900,20 +900,23 @@ static int madvise_inject_error(int beha
 		 */
 		size = page_size(compound_head(page));
 
+		/*
+		 * The get_user_pages_fast() is just to get the pfn of the
+		 * given address, and the refcount has nothing to do with
+		 * what we try to test, so it should be released immediately.
+		 * This is racy but it's intended because the real hardware
+		 * errors could happen at any moment and memory error handlers
+		 * must properly handle the race.
+		 */
+		put_page(page);
+
 		if (behavior == MADV_SOFT_OFFLINE) {
 			pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
 				 pfn, start);
-			ret = soft_offline_page(pfn, MF_COUNT_INCREASED);
+			ret = soft_offline_page(pfn, 0);
 		} else {
 			pr_info("Injecting memory failure for pfn %#lx at process virtual address %#lx\n",
 				 pfn, start);
-			/*
-			 * Drop the page reference taken by get_user_pages_fast(). In
-			 * the absence of MF_COUNT_INCREASED the memory_failure()
-			 * routine is responsible for pinning the page to prevent it
-			 * from being released back to the page allocator.
-			 */
-			put_page(page);
 			ret = memory_failure(pfn, 0);
 		}
 
_

Patches currently in -mm which might be from naoya.horiguchi@nec.com are

mmmadvise-call-soft_offline_page-without-mf_count_increased.patch
mmhwpoison-remove-mf_count_increased.patch
mmhwpoison-remove-flag-argument-from-soft-offline-functions.patch


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-11-20 23:59 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-24 19:19 + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree akpm
2020-07-03 22:14 incoming Andrew Morton
2020-07-16 21:45 ` + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree Andrew Morton
2020-07-24  4:14 incoming Andrew Morton
2020-07-31 20:05 ` + mmmadvise-call-soft_offline_page-without-mf_count_increased.patch added to -mm tree Andrew Morton
2020-11-20 23:58 akpm

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