From 4391b5f49e28bdb78ddf67495abb2f767474216d Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Tue, 10 Jan 2012 15:07:03 -0800 Subject: vmscan: activate executable pages after first usage 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 Cc: Pekka Enberg Cc: Minchan Kim Cc: KAMEZAWA Hiroyuki Cc: Wu Fengguang Cc: Johannes Weiner Cc: Nick Piggin Cc: Mel Gorman Cc: Shaohua Li Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman --- mm/vmscan.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'mm') diff --git a/mm/vmscan.c b/mm/vmscan.c index 811141e166e0..fed30222e4ab 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; } -- cgit v1.2.3