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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2018-03-23 02:17:31 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-28 19:22:58 +0300 |
| commit | 29c11d86b74ff6b4795ed715d23211e89c209425 (patch) | |
| tree | 82cb5b11399ed59d8b565128c3cfbce9c090f1ae | |
| parent | babe10f62b6bf7cc30ae85cb2f1e382c210219fd (diff) | |
| download | linux-29c11d86b74ff6b4795ed715d23211e89c209425.tar.xz | |
mm/thp: do not wait for lock_page() in deferred_split_scan()
commit fa41b900c30b45fab03783724932dc30cd46a6be upstream.
deferred_split_scan() gets called from reclaim path. Waiting for page
lock may lead to deadlock there.
Replace lock_page() with trylock_page() and skip the page if we failed
to lock it. We will get to the page on the next scan.
Link: http://lkml.kernel.org/r/20180315150747.31945-1-kirill.shutemov@linux.intel.com
Fixes: 9a982250f773 ("thp: introduce deferred_split_huge_page()")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/huge_memory.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 0e7ded98d114..4ed6c89e95c3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2791,11 +2791,13 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, list_for_each_safe(pos, next, &list) { page = list_entry((void *)pos, struct page, mapping); - lock_page(page); + if (!trylock_page(page)) + goto next; /* split_huge_page() removes page from list on success */ if (!split_huge_page(page)) split++; unlock_page(page); +next: put_page(page); } |