The patch titled
thp: fix unsuitable behavior for hwpoisoned tail page
has been added to the -mm tree. Its filename is
thp-fix-unsuitable-behavior-for-hwpoisoned-tail-page.patch
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See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: thp: fix unsuitable behavior for hwpoisoned tail page
From: Jin Dongming <jin.dongming@xxxxxxxxxxxxxxxxxx>
When a tail page of THP is poisoned, memory-failure will do nothing except
setting PG_hwpoison, while the expected behavior is that the process, who
is using the poisoned tail page, should be killed.
The above problem is caused by lru check of the poisoned tail page of THP.
Because PG_lru flag is only set on the head page of THP, the check always
consider the poisoned tail page as NON lru page.
So the lru check for the tail page of THP should be avoided, as like as
hugetlb.
This patch adds !PageTransCompound() before lru check for THP, because of
the check (!PageHuge() && !PageTransCompound()) the whole branch could be
optimized away at build time when both hugetlbfs and THP are set with "N"
(or in archs not supporting either of those).
Signed-off-by: Jin Dongming <jin.dongming@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)
diff -puN mm/memory-failure.c~thp-fix-unsuitable-behavior-for-hwpoisoned-tail-page mm/memory-failure.c
--- a/mm/memory-failure.c~thp-fix-unsuitable-behavior-for-hwpoisoned-tail-page
+++ a/mm/memory-failure.c
@@ -1065,19 +1065,22 @@ int __memory_failure(unsigned long pfn,
* The check (unnecessarily) ignores LRU pages being isolated and
* walked by the page reclaim code, however that's not a big loss.
*/
- if (!PageLRU(p) && !PageHuge(p))
- shake_page(p, 0);
- if (!PageLRU(p) && !PageHuge(p)) {
- /*
- * shake_page could have turned it free.
- */
- if (is_free_buddy_page(p)) {
- action_result(pfn, "free buddy, 2nd try", DELAYED);
- return 0;
+ if (!PageHuge(p) && !PageTransCompound(p)) {
+ if (!PageLRU(p))
+ shake_page(p, 0);
+ if (!PageLRU(p)) {
+ /*
+ * shake_page could have turned it free.
+ */
+ if (is_free_buddy_page(p)) {
+ action_result(pfn, "free buddy, 2nd try",
+ DELAYED);
+ return 0;
+ }
+ action_result(pfn, "non LRU", IGNORED);
+ put_page(p);
+ return -EBUSY;
}
- action_result(pfn, "non LRU", IGNORED);
- put_page(p);
- return -EBUSY;
}
/*
_
Patches currently in -mm which might be from jin.dongming@xxxxxxxxxxxxxxxxxx are
thp-fix-splitting-of-hwpoisoned-hugepages.patch
thp-fix-the-wrong-reported-address-of-hwpoisoned-hugepages.patch
thp-fix-the-wrong-reported-address-of-hwpoisoned-hugepages-fix.patch
thp-fix-unsuitable-behavior-for-hwpoisoned-tail-page.patch
thp-fix-unsuitable-behavior-for-hwpoisoned-tail-page-fix.patch
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