From: Konstantin Khlebnikov <[email protected]>
commit c909e99364c8b6ca07864d752950b6b4ecf6bef4 upstream.
Stable note: Not tracked in Bugzilla. There were reports of shared
mapped pages being unfairly reclaimed in comparison to older kernels.
This is being addressed over time.
Logic added in commit 8cab4754d24a0 ("vmscan: make mapped executable pages
the first class citizen") was noticeably weakened in commit
645747462435d84 ("vmscan: detect mapped file pages used only once").
Currently these pages can become "first class citizens" only after second
usage. After this patch page_check_references() will activate they after
first usage, and executable code gets yet better chance to stay in memory.
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Wu Fengguang <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Rik van Riel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Mel Gorman <[email protected]>
---
mm/vmscan.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7edaaac..8b98a75 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -726,6 +726,12 @@ static enum page_references page_check_references(struct
page *page,
if (referenced_page || referenced_ptes > 1)
return PAGEREF_ACTIVATE;
+ /*
+ * Activate file-backed executable pages after first usage.
+ */
+ if (vm_flags & VM_EXEC)
+ return PAGEREF_ACTIVATE;
+
return PAGEREF_KEEP;
}
--
1.7.9.2
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