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* + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree
@ 2020-08-07  1:07 akpm
  0 siblings, 0 replies; 5+ messages in thread
From: akpm @ 2020-08-07  1:07 UTC (permalink / raw)
  To: aneesh.kumar, aneesh.kumar, cai, dave.hansen, david, mhocko,
	mike.kravetz, mm-commits, naoya.horiguchi, osalvador, osalvador,
	tony.luck, zeil


The patch titled
     Subject: mm,hwpoison: rework soft offline for free pages
has been added to the -mm tree.  Its filename is
     mmhwpoison-rework-soft-offline-for-free-pages.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.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: Oscar Salvador <osalvador@suse.de>
Subject: mm,hwpoison: rework soft offline for free pages

When trying to soft-offline a free page, we need to first take it off the
buddy allocator.  Once we know is out of reach, we can safely flag it as
poisoned.

take_page_off_buddy will be used to take a page meant to be poisoned off
the buddy allocator.  take_page_off_buddy calls break_down_buddy_pages,
which splits a higher-order page in case our page belongs to one.

Once the page is under our control, we call page_handle_poison to set it
as poisoned and grab a refcount on it.

Link: http://lkml.kernel.org/r/20200806184923.7007-8-nao.horiguchi@gmail.com
Signed-off-by: Oscar Salvador <osalvador@suse.com>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
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: Qian Cai <cai@lca.pw>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/page-flags.h |    1 
 mm/memory-failure.c        |   18 ++++++---
 mm/page_alloc.c            |   68 +++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 6 deletions(-)

--- a/include/linux/page-flags.h~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/include/linux/page-flags.h
@@ -423,6 +423,7 @@ PAGEFLAG(HWPoison, hwpoison, PF_ANY)
 TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
 #define __PG_HWPOISON (1UL << PG_hwpoison)
 extern bool set_hwpoison_free_buddy_page(struct page *page);
+extern bool take_page_off_buddy(struct page *page);
 #else
 PAGEFLAG_FALSE(HWPoison)
 static inline bool set_hwpoison_free_buddy_page(struct page *page)
--- a/mm/memory-failure.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/memory-failure.c
@@ -65,6 +65,13 @@ int sysctl_memory_failure_recovery __rea
 
 atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
 
+static void page_handle_poison(struct page *page)
+{
+	SetPageHWPoison(page);
+	page_ref_inc(page);
+	num_poisoned_pages_inc();
+}
+
 #if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
 
 u32 hwpoison_filter_enable = 0;
@@ -1882,14 +1889,13 @@ static int soft_offline_in_use_page(stru
 
 static int soft_offline_free_page(struct page *page)
 {
-	int rc = dissolve_free_huge_page(page);
+	int rc = -EBUSY;
 
-	if (!rc) {
-		if (set_hwpoison_free_buddy_page(page))
-			num_poisoned_pages_inc();
-		else
-			rc = -EBUSY;
+	if (!dissolve_free_huge_page(page) && take_page_off_buddy(page)) {
+		page_handle_poison(page);
+		rc = 0;
 	}
+
 	return rc;
 }
 
--- a/mm/page_alloc.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/page_alloc.c
@@ -8773,6 +8773,74 @@ bool is_free_buddy_page(struct page *pag
 
 #ifdef CONFIG_MEMORY_FAILURE
 /*
+ * Break down a higher-order page in sub-pages, and keep our target out of
+ * buddy allocator.
+ */
+static void break_down_buddy_pages(struct zone *zone, struct page *page,
+				   struct page *target, int low, int high,
+				   int migratetype)
+{
+	unsigned long size = 1 << high;
+	struct page *current_buddy, *next_page;
+
+	while (high > low) {
+		high--;
+		size >>= 1;
+
+		if (target >= &page[size]) {
+			next_page = page + size;
+			current_buddy = page;
+		} else {
+			next_page = page;
+			current_buddy = page + size;
+		}
+
+		if (set_page_guard(zone, current_buddy, high, migratetype))
+			continue;
+
+		if (current_buddy != target) {
+			add_to_free_list(current_buddy, zone, high, migratetype);
+			set_page_order(current_buddy, high);
+			page = next_page;
+		}
+	}
+}
+
+/*
+ * Take a page that will be marked as poisoned off the buddy allocator.
+ */
+bool take_page_off_buddy(struct page *page)
+{
+	struct zone *zone = page_zone(page);
+	unsigned long pfn = page_to_pfn(page);
+	unsigned long flags;
+	unsigned int order;
+	bool ret = false;
+
+	spin_lock_irqsave(&zone->lock, flags);
+	for (order = 0; order < MAX_ORDER; order++) {
+		struct page *page_head = page - (pfn & ((1 << order) - 1));
+		int buddy_order = page_order(page_head);
+
+		if (PageBuddy(page_head) && buddy_order >= order) {
+			unsigned long pfn_head = page_to_pfn(page_head);
+			int migratetype = get_pfnblock_migratetype(page_head,
+								   pfn_head);
+
+			del_page_from_free_list(page_head, zone, buddy_order);
+			break_down_buddy_pages(zone, page_head, page, 0,
+						buddy_order, migratetype);
+			ret = true;
+			break;
+		}
+		if (page_count(page_head) > 0)
+			break;
+	}
+	spin_unlock_irqrestore(&zone->lock, flags);
+	return ret;
+}
+
+/*
  * Set PG_hwpoison flag if a given page is confirmed to be a free page.  This
  * test is performed under the zone lock to prevent a race against page
  * allocation.
_

Patches currently in -mm which might be from osalvador@suse.de are

mmhwpoison-un-export-get_hwpoison_page-and-make-it-static.patch
mmhwpoison-kill-put_hwpoison_page.patch
mmhwpoison-unify-thp-handling-for-hard-and-soft-offline.patch
mmhwpoison-rework-soft-offline-for-free-pages.patch
mmhwpoison-rework-soft-offline-for-in-use-pages.patch
mmhwpoison-refactor-soft_offline_huge_page-and-__soft_offline_page.patch
mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline.patch


^ permalink raw reply	[flat|nested] 5+ messages in thread
* + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree
@ 2020-09-22 17:00 akpm
  0 siblings, 0 replies; 5+ messages in thread
From: akpm @ 2020-09-22 17:00 UTC (permalink / raw)
  To: mm-commits, zeil, tony.luck, osalvador, naoya.horiguchi,
	mike.kravetz, mhocko, david, dave.hansen, cai, aris,
	aneesh.kumar, aneesh.kumar, osalvador


The patch titled
     Subject: mm,hwpoison: rework soft offline for free pages
has been added to the -mm tree.  Its filename is
     mmhwpoison-rework-soft-offline-for-free-pages.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.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: Oscar Salvador <osalvador@suse.de>
Subject: mm,hwpoison: rework soft offline for free pages

When trying to soft-offline a free page, we need to first take it off the
buddy allocator.  Once we know is out of reach, we can safely flag it as
poisoned.

take_page_off_buddy will be used to take a page meant to be poisoned off
the buddy allocator.  take_page_off_buddy calls break_down_buddy_pages,
which splits a higher-order page in case our page belongs to one.

Once the page is under our control, we call page_handle_poison to set it
as poisoned and grab a refcount on it.

Link: https://lkml.kernel.org/r/20200922135650.1634-9-osalvador@suse.de
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: Aristeu Rozanski <aris@ruivo.org>
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: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/page-flags.h |    1 
 mm/memory-failure.c        |   18 ++++++---
 mm/page_alloc.c            |   68 +++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 6 deletions(-)

--- a/include/linux/page-flags.h~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/include/linux/page-flags.h
@@ -429,6 +429,7 @@ PAGEFLAG(HWPoison, hwpoison, PF_ANY)
 TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
 #define __PG_HWPOISON (1UL << PG_hwpoison)
 extern bool set_hwpoison_free_buddy_page(struct page *page);
+extern bool take_page_off_buddy(struct page *page);
 #else
 PAGEFLAG_FALSE(HWPoison)
 static inline bool set_hwpoison_free_buddy_page(struct page *page)
--- a/mm/memory-failure.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/memory-failure.c
@@ -65,6 +65,13 @@ int sysctl_memory_failure_recovery __rea
 
 atomic_long_t num_poisoned_pages __read_mostly = ATOMIC_LONG_INIT(0);
 
+static void page_handle_poison(struct page *page)
+{
+	SetPageHWPoison(page);
+	page_ref_inc(page);
+	num_poisoned_pages_inc();
+}
+
 #if defined(CONFIG_HWPOISON_INJECT) || defined(CONFIG_HWPOISON_INJECT_MODULE)
 
 u32 hwpoison_filter_enable = 0;
@@ -1884,14 +1891,13 @@ static int soft_offline_in_use_page(stru
 
 static int soft_offline_free_page(struct page *page)
 {
-	int rc = dissolve_free_huge_page(page);
+	int rc = -EBUSY;
 
-	if (!rc) {
-		if (set_hwpoison_free_buddy_page(page))
-			num_poisoned_pages_inc();
-		else
-			rc = -EBUSY;
+	if (!dissolve_free_huge_page(page) && take_page_off_buddy(page)) {
+		page_handle_poison(page);
+		rc = 0;
 	}
+
 	return rc;
 }
 
--- a/mm/page_alloc.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/page_alloc.c
@@ -8759,6 +8759,74 @@ bool is_free_buddy_page(struct page *pag
 
 #ifdef CONFIG_MEMORY_FAILURE
 /*
+ * Break down a higher-order page in sub-pages, and keep our target out of
+ * buddy allocator.
+ */
+static void break_down_buddy_pages(struct zone *zone, struct page *page,
+				   struct page *target, int low, int high,
+				   int migratetype)
+{
+	unsigned long size = 1 << high;
+	struct page *current_buddy, *next_page;
+
+	while (high > low) {
+		high--;
+		size >>= 1;
+
+		if (target >= &page[size]) {
+			next_page = page + size;
+			current_buddy = page;
+		} else {
+			next_page = page;
+			current_buddy = page + size;
+		}
+
+		if (set_page_guard(zone, current_buddy, high, migratetype))
+			continue;
+
+		if (current_buddy != target) {
+			add_to_free_list(current_buddy, zone, high, migratetype);
+			set_page_order(current_buddy, high);
+			page = next_page;
+		}
+	}
+}
+
+/*
+ * Take a page that will be marked as poisoned off the buddy allocator.
+ */
+bool take_page_off_buddy(struct page *page)
+{
+	struct zone *zone = page_zone(page);
+	unsigned long pfn = page_to_pfn(page);
+	unsigned long flags;
+	unsigned int order;
+	bool ret = false;
+
+	spin_lock_irqsave(&zone->lock, flags);
+	for (order = 0; order < MAX_ORDER; order++) {
+		struct page *page_head = page - (pfn & ((1 << order) - 1));
+		int buddy_order = page_order(page_head);
+
+		if (PageBuddy(page_head) && buddy_order >= order) {
+			unsigned long pfn_head = page_to_pfn(page_head);
+			int migratetype = get_pfnblock_migratetype(page_head,
+								   pfn_head);
+
+			del_page_from_free_list(page_head, zone, buddy_order);
+			break_down_buddy_pages(zone, page_head, page, 0,
+						buddy_order, migratetype);
+			ret = true;
+			break;
+		}
+		if (page_count(page_head) > 0)
+			break;
+	}
+	spin_unlock_irqrestore(&zone->lock, flags);
+	return ret;
+}
+
+/*
  * Set PG_hwpoison flag if a given page is confirmed to be a free page.  This
  * test is performed under the zone lock to prevent a race against page
  * allocation.
_

Patches currently in -mm which might be from osalvador@suse.de are

mmhwpoison-unexport-get_hwpoison_page-and-make-it-static.patch
mmhwpoison-refactor-madvise_inject_error.patch
mmhwpoison-kill-put_hwpoison_page.patch
mmhwpoison-unify-thp-handling-for-hard-and-soft-offline.patch
mmhwpoison-rework-soft-offline-for-free-pages.patch
mmhwpoison-rework-soft-offline-for-in-use-pages.patch
mmhwpoison-refactor-soft_offline_huge_page-and-__soft_offline_page.patch
mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline.patch
mmhwpoison-try-to-narrow-window-race-for-free-pages.patch
mmhwpoison-take-free-pages-off-the-buddy-freelists.patch
mmhwpoison-drain-pcplists-before-bailing-out-for-non-buddy-zero-refcount-page.patch
mmhwpoison-drop-unneeded-pcplist-draining.patch
mmhwpoison-remove-stale-code.patch


^ permalink raw reply	[flat|nested] 5+ messages in thread
* incoming
@ 2020-07-24  4:14 Andrew Morton
  2020-07-31 20:06 ` + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree Andrew Morton
  0 siblings, 1 reply; 5+ 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] 5+ messages in thread
* incoming
@ 2020-07-03 22:14 Andrew Morton
  2020-07-16 21:46 ` + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree Andrew Morton
  0 siblings, 1 reply; 5+ 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] 5+ messages in thread
* + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree
@ 2020-06-24 19:19 akpm
  0 siblings, 0 replies; 5+ messages in thread
From: akpm @ 2020-06-24 19:19 UTC (permalink / raw)
  To: mm-commits, zeil, tony.luck, naoya.horiguchi, mike.kravetz,
	mhocko, david, dave.hansen, aneesh.kumar, aneesh.kumar,
	osalvador


The patch titled
     Subject: mm,hwpoison: rework soft offline for free pages
has been added to the -mm tree.  Its filename is
     mmhwpoison-rework-soft-offline-for-free-pages.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mmhwpoison-rework-soft-offline-for-free-pages.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: Oscar Salvador <osalvador@suse.de>
Subject: mm,hwpoison: rework soft offline for free pages

When trying to soft-offline a free page, we need to first take it off the
buddy allocator.  Once we know is out of reach, we can safely flag it as
poisoned.

take_page_off_buddy will be used to take a page meant to be poisoned off
the buddy allocator.  take_page_off_buddy calls break_down_buddy_pages,
which splits a higher-order page in case our page belongs to one.

Once the page is under our control, we call page_handle_poison to set it
as poisoned and grab a refcount on it.

Link: http://lkml.kernel.org/r/20200624150137.7052-12-nao.horiguchi@gmail.com
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
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>
---

 include/linux/page-flags.h |    1 
 mm/memory-failure.c        |   18 ++++++---
 mm/page_alloc.c            |   68 +++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+), 6 deletions(-)

--- a/include/linux/page-flags.h~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/include/linux/page-flags.h
@@ -423,6 +423,7 @@ PAGEFLAG(HWPoison, hwpoison, PF_ANY)
 TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
 #define __PG_HWPOISON (1UL << PG_hwpoison)
 extern bool set_hwpoison_free_buddy_page(struct page *page);
+extern bool take_page_off_buddy(struct page *page);
 #else
 PAGEFLAG_FALSE(HWPoison)
 static inline bool set_hwpoison_free_buddy_page(struct page *page)
--- a/mm/memory-failure.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/memory-failure.c
@@ -78,6 +78,13 @@ EXPORT_SYMBOL_GPL(hwpoison_filter_dev_mi
 EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
 EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
 
+static void page_handle_poison(struct page *page)
+{
+	SetPageHWPoison(page);
+	page_ref_inc(page);
+	num_poisoned_pages_inc();
+}
+
 static int hwpoison_filter_dev(struct page *p)
 {
 	struct address_space *mapping;
@@ -1876,14 +1883,13 @@ static int soft_offline_in_use_page(stru
 
 static int soft_offline_free_page(struct page *page)
 {
-	int rc = dissolve_free_huge_page(page);
+	int rc = -EBUSY;
 
-	if (!rc) {
-		if (set_hwpoison_free_buddy_page(page))
-			num_poisoned_pages_inc();
-		else
-			rc = -EBUSY;
+	if (!dissolve_free_huge_page(page) && take_page_off_buddy(page)) {
+		page_handle_poison(page);
+		rc = 0;
 	}
+
 	return rc;
 }
 
--- a/mm/page_alloc.c~mmhwpoison-rework-soft-offline-for-free-pages
+++ a/mm/page_alloc.c
@@ -8782,6 +8782,74 @@ bool is_free_buddy_page(struct page *pag
 
 #ifdef CONFIG_MEMORY_FAILURE
 /*
+ * Break down a higher-order page in sub-pages, and keep our target out of
+ * buddy allocator.
+ */
+static void break_down_buddy_pages(struct zone *zone, struct page *page,
+				   struct page *target, int low, int high,
+				   int migratetype)
+{
+	unsigned long size = 1 << high;
+	struct page *current_buddy, *next_page;
+
+	while (high > low) {
+		high--;
+		size >>= 1;
+
+		if (target >= &page[size]) {
+			next_page = page + size;
+			current_buddy = page;
+		} else {
+			next_page = page;
+			current_buddy = page + size;
+		}
+
+		if (set_page_guard(zone, current_buddy, high, migratetype))
+			continue;
+
+		if (current_buddy != target) {
+			add_to_free_list(current_buddy, zone, high, migratetype);
+			set_page_order(current_buddy, high);
+			page = next_page;
+		}
+	}
+}
+
+/*
+ * Take a page that will be marked as poisoned off the buddy allocator.
+ */
+bool take_page_off_buddy(struct page *page)
+{
+	struct zone *zone = page_zone(page);
+	unsigned long pfn = page_to_pfn(page);
+	unsigned long flags;
+	unsigned int order;
+	bool ret = false;
+
+	spin_lock_irqsave(&zone->lock, flags);
+	for (order = 0; order < MAX_ORDER; order++) {
+		struct page *page_head = page - (pfn & ((1 << order) - 1));
+		int buddy_order = page_order(page_head);
+
+		if (PageBuddy(page_head) && buddy_order >= order) {
+			unsigned long pfn_head = page_to_pfn(page_head);
+			int migratetype = get_pfnblock_migratetype(page_head,
+								   pfn_head);
+
+			del_page_from_free_list(page_head, zone, buddy_order);
+			break_down_buddy_pages(zone, page_head, page, 0,
+						buddy_order, migratetype);
+			ret = true;
+			break;
+		}
+		if (page_count(page_head) > 0)
+			break;
+	}
+	spin_unlock_irqrestore(&zone->lock, flags);
+	return ret;
+}
+
+/*
  * Set PG_hwpoison flag if a given page is confirmed to be a free page.  This
  * test is performed under the zone lock to prevent a race against page
  * allocation.
_

Patches currently in -mm which might be from osalvador@suse.de are

mmmadvise-refactor-madvise_inject_error.patch
mmhwpoison-un-export-get_hwpoison_page-and-make-it-static.patch
mmhwpoison-kill-put_hwpoison_page.patch
mmhwpoison-unify-thp-handling-for-hard-and-soft-offline.patch
mmhwpoison-rework-soft-offline-for-free-pages.patch
mmhwpoison-rework-soft-offline-for-in-use-pages.patch
mmhwpoison-refactor-soft_offline_huge_page-and-__soft_offline_page.patch
mmhwpoison-return-0-if-the-page-is-already-poisoned-in-soft-offline.patch

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, back to index

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-07  1:07 + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree akpm
  -- strict thread matches above, loose matches on Subject: below --
2020-09-22 17:00 akpm
2020-07-24  4:14 incoming Andrew Morton
2020-07-31 20:06 ` + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree Andrew Morton
2020-07-03 22:14 incoming Andrew Morton
2020-07-16 21:46 ` + mmhwpoison-rework-soft-offline-for-free-pages.patch added to -mm tree Andrew Morton
2020-06-24 19:19 akpm

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