The patch titled
Subject: mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage
has been added to the -mm mm-unstable branch. Its filename is
mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Subject: mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage
Date: Wed, 21 Sep 2022 18:13:56 +0900
Patch series " mm, hwpoison: improve handling workload related to hugetlb
and memory_hotplug", v3.
This patchset tries to solve the issue among memory_hotplug, hugetlb and
hwpoison. Based on the review over v2 by Miaohe (thank you!), 1/4 takes
another approach to prevent hwpoisoned hugepages to be migrated (i.e.
the corrupted data is accessed) in memory hotremove.
In this patchset, memory hotplug handles hwpoison pages like below:
- hwpoison pages should not prevent memory hotremove,
- memory block with hwpoison pages should not be onlined.
This patch (of 4):
HWPoisoned page is not supposed to be accessed once marked, but currently
such accesses can happen during memory hotremove because do_migrate_range()
can be called before dissolve_free_huge_pages() is called.
Clear HPageMigratable for hwpoisoned hugepages to prevent them from being
migrated. This should be done in hugetlb_lock to avoid race against
isolate_hugetlb().
get_hwpoison_huge_page() needs to have a flag to show it's called from
unpoison to take refcount of hwpoisoned hugepages, so add it.
Link: https://lkml.kernel.org/r/20220921091359.25889-1-naoya.horiguchi@xxxxxxxxx
Link: https://lkml.kernel.org/r/20220921091359.25889-2-naoya.horiguchi@xxxxxxxxx
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Reported-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/hugetlb.h~mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage
+++ a/include/linux/hugetlb.h
@@ -183,7 +183,7 @@ bool hugetlb_reserve_pages(struct inode
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
long freed);
int isolate_hugetlb(struct page *page, struct list_head *list);
-int get_hwpoison_huge_page(struct page *page, bool *hugetlb);
+int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison);
int get_huge_page_for_hwpoison(unsigned long pfn, int flags);
void putback_active_hugepage(struct page *page);
void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason);
@@ -391,7 +391,7 @@ static inline int isolate_hugetlb(struct
return -EBUSY;
}
-static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
+static inline int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison)
{
return 0;
}
--- a/mm/hugetlb.c~mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage
+++ a/mm/hugetlb.c
@@ -7207,7 +7207,7 @@ unlock:
return ret;
}
-int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
+int get_hwpoison_huge_page(struct page *page, bool *hugetlb, bool unpoison)
{
int ret = 0;
@@ -7217,7 +7217,7 @@ int get_hwpoison_huge_page(struct page *
*hugetlb = true;
if (HPageFreed(page))
ret = 0;
- else if (HPageMigratable(page))
+ else if (HPageMigratable(page) || unpoison)
ret = get_page_unless_zero(page);
else
ret = -EBUSY;
--- a/mm/memory-failure.c~mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage
+++ a/mm/memory-failure.c
@@ -1244,7 +1244,7 @@ static int __get_hwpoison_page(struct pa
int ret = 0;
bool hugetlb = false;
- ret = get_hwpoison_huge_page(head, &hugetlb);
+ ret = get_hwpoison_huge_page(head, &hugetlb, false);
if (hugetlb)
return ret;
@@ -1334,7 +1334,7 @@ static int __get_unpoison_page(struct pa
int ret = 0;
bool hugetlb = false;
- ret = get_hwpoison_huge_page(head, &hugetlb);
+ ret = get_hwpoison_huge_page(head, &hugetlb, true);
if (hugetlb)
return ret;
@@ -1815,6 +1815,13 @@ int __get_huge_page_for_hwpoison(unsigne
goto out;
}
+ /*
+ * Clearing HPageMigratable for hwpoisoned hugepages to prevent them
+ * from being migrated by memory hotremove.
+ */
+ if (count_increased)
+ ClearHPageMigratable(head);
+
return ret;
out:
if (count_increased)
@@ -1862,6 +1869,7 @@ retry:
if (hwpoison_filter(p)) {
hugetlb_clear_page_hwpoison(head);
+ SetHPageMigratable(head);
unlock_page(head);
if (res == 1)
put_page(head);
_
Patches currently in -mm which might be from naoya.horiguchi@xxxxxxx are
mm-huge_memory-use-pfn_to_online_page-in-split_huge_pages_all.patch
mmhwpoisonhugetlbmemory_hotplug-hotremove-memory-section-with-hwpoisoned-hugepage.patch
mm-hwpoison-move-definitions-of-num_poisoned_pages_-to-memory-failurec.patch
mm-hwpoison-pass-pfn-to-num_poisoned_pages_.patch
mm-hwpoison-introduce-per-memory_block-hwpoison-counter.patch
