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authorHuang Ying <ying.huang@intel.com>2017-09-07 02:22:19 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 03:27:27 +0300
commitba3c4ce6def4915093be80585ff69f780630f32f (patch)
tree3fa890d652981cc54c5ebd7ea59cfc134fad4a6c /include/linux/swap.h
parente07098294adfd03d582af7626752255e3d170393 (diff)
downloadlinux-ba3c4ce6def4915093be80585ff69f780630f32f.tar.xz
mm, THP, swap: make reuse_swap_page() works for THP swapped out
After supporting to delay THP (Transparent Huge Page) splitting after swapped out, it is possible that some page table mappings of the THP are turned into swap entries. So reuse_swap_page() need to check the swap count in addition to the map count as before. This patch done that. In the huge PMD write protect fault handler, in addition to the page map count, the swap count need to be checked too, so the page lock need to be acquired too when calling reuse_swap_page() in addition to the page table lock. [ying.huang@intel.com: silence a compiler warning] Link: http://lkml.kernel.org/r/87bmnzizjy.fsf@yhuang-dev.intel.com Link: http://lkml.kernel.org/r/20170724051840.2309-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michal Hocko <mhocko@kernel.org> Cc: Ross Zwisler <ross.zwisler@intel.com> [for brd.c, zram_drv.c, pmem.c] Cc: Vishal L Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
-rw-r--r--include/linux/swap.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 964b4f1fba4a..7176ba780e83 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -510,8 +510,8 @@ static inline int swp_swapcount(swp_entry_t entry)
return 0;
}
-#define reuse_swap_page(page, total_mapcount) \
- (page_trans_huge_mapcount(page, total_mapcount) == 1)
+#define reuse_swap_page(page, total_map_swapcount) \
+ (page_trans_huge_mapcount(page, total_map_swapcount) == 1)
static inline int try_to_free_swap(struct page *page)
{