Subject: + hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage.patch added to -mm tree
To: slaoub@xxxxxxxxx,ak@xxxxxxxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,stable@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 12 May 2014 15:56:24 -0700
The patch titled
Subject: HWPOSION, hugetlb: lock_page/unlock_page does not match for handling a free hugepage
has been added to the -mm tree. Its filename is
hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage.patch
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------------------------------------------------------
From: Chen Yucong <slaoub@xxxxxxxxx>
Subject: HWPOSION, hugetlb: lock_page/unlock_page does not match for handling a free hugepage
For handling a free hugepage in memory failure, the race will happen if
another thread hwpoisoned this hugepage concurrently. So we need to check
PageHWPoison instead of !PageHWPoison.
If hwpoison_filter(p) returns true or a race happens, then we need to
unlock_page(hpage).
Signed-off-by: Chen Yucong <slaoub@xxxxxxxxx>
Reviewed-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Tested-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [2.6.36+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff -puN mm/memory-failure.c~hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage mm/memory-failure.c
--- a/mm/memory-failure.c~hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage
+++ a/mm/memory-failure.c
@@ -1081,15 +1081,16 @@ int memory_failure(unsigned long pfn, in
return 0;
} else if (PageHuge(hpage)) {
/*
- * Check "just unpoisoned", "filter hit", and
- * "race with other subpage."
+ * Check "filter hit" and "race with other subpage."
*/
lock_page(hpage);
- if (!PageHWPoison(hpage)
- || (hwpoison_filter(p) && TestClearPageHWPoison(p))
- || (p != hpage && TestSetPageHWPoison(hpage))) {
- atomic_long_sub(nr_pages, &num_poisoned_pages);
- return 0;
+ if (PageHWPoison(hpage)) {
+ if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
+ || (p != hpage && TestSetPageHWPoison(hpage))) {
+ atomic_long_sub(nr_pages, &num_poisoned_pages);
+ unlock_page(hpage);
+ return 0;
+ }
}
set_page_hwpoison_huge_page(hpage);
res = dequeue_hwpoisoned_huge_page(hpage);
_
Patches currently in -mm which might be from slaoub@xxxxxxxxx are
hwposion-hugetlb-lock_page-unlock_page-does-not-match-for-handling-a-free-hugepage.patch
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