diff options
| author | Dean Nelson <dnelson@redhat.com> | 2012-03-22 03:34:05 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-22 04:54:58 +0400 |
| commit | 385de35722c9a22917e7bc5e63cd83a8cffa5ecd (patch) | |
| tree | 41ae2e23e096d189cdf614cf1eaf0c8f9ddeeb3b | |
| parent | 6d9d88d07e132259c35f9493b15429e19198489c (diff) | |
| download | linux-385de35722c9a22917e7bc5e63cd83a8cffa5ecd.tar.xz | |
thp: allow a hwpoisoned head page to be put back to LRU
Andrea Arcangeli pointed out to me that a check in __memory_failure()
which was intended to prevent THP tail pages from being checked for the
absence of the PG_lru flag (something that is always the case), was also
preventing THP head pages from being checked.
A THP head page could actually benefit from the call to shake_page() by
ending up being put back to a LRU, provided it had been waiting in a
pagevec array.
Andrea suggested that the "!PageTransCompound(p)" in the if-statement
should be replaced by a "!PageTransTail(p)", thus allowing THP head pages
to be checked and possibly shaken.
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Cc: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/page-flags.h | 20 | ||||
| -rw-r--r-- | mm/memory-failure.c | 2 |
2 files changed, 21 insertions, 1 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index e90a673be67e..6b25758e028e 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -414,11 +414,26 @@ static inline int PageTransHuge(struct page *page) return PageHead(page); } +/* + * PageTransCompound returns true for both transparent huge pages + * and hugetlbfs pages, so it should only be called when it's known + * that hugetlbfs pages aren't involved. + */ static inline int PageTransCompound(struct page *page) { return PageCompound(page); } +/* + * PageTransTail returns true for both transparent huge pages + * and hugetlbfs pages, so it should only be called when it's known + * that hugetlbfs pages aren't involved. + */ +static inline int PageTransTail(struct page *page) +{ + return PageTail(page); +} + #else static inline int PageTransHuge(struct page *page) @@ -430,6 +445,11 @@ static inline int PageTransCompound(struct page *page) { return 0; } + +static inline int PageTransTail(struct page *page) +{ + return 0; +} #endif #ifdef CONFIG_MMU diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 56080ea36140..c22076ffdd44 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1063,7 +1063,7 @@ int __memory_failure(unsigned long pfn, int trapno, int flags) * The check (unnecessarily) ignores LRU pages being isolated and * walked by the page reclaim code, however that's not a big loss. */ - if (!PageHuge(p) && !PageTransCompound(p)) { + if (!PageHuge(p) && !PageTransTail(p)) { if (!PageLRU(p)) shake_page(p, 0); if (!PageLRU(p)) { |