From 11d16c25bbf7a3b7a43d7472e175cdd52961757d Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 22 Feb 2013 16:32:15 -0800 Subject: mm: vmscan: improve comment on low-page cache handling Fix comment style and elaborate on why anonymous memory is force-scanned when file cache runs low. Signed-off-by: Johannes Weiner Reviewed-by: Rik van Riel Acked-by: Mel Gorman Reviewed-by: Michal Hocko Cc: Hugh Dickins Cc: Satoru Moriya Cc: Simon Jeons Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 68586c887611..259f8208a388 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1713,13 +1713,15 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, file = get_lru_size(lruvec, LRU_ACTIVE_FILE) + get_lru_size(lruvec, LRU_INACTIVE_FILE); + /* + * If it's foreseeable that reclaiming the file cache won't be + * enough to get the zone back into a desirable shape, we have + * to swap. Better start now and leave the - probably heavily + * thrashing - remaining file pages alone. + */ if (global_reclaim(sc)) { - free = zone_page_state(zone, NR_FREE_PAGES); + free = zone_page_state(zone, NR_FREE_PAGES); if (unlikely(file + free <= high_wmark_pages(zone))) { - /* - * If we have very few page cache pages, force-scan - * anon pages. - */ fraction[0] = 1; fraction[1] = 0; denominator = 1; -- cgit v1.2.2