From 5a1c84b404a7176b8b36e2a0041b6f0adb3151a3 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 28 Jul 2016 15:47:31 -0700 Subject: mm: remove reclaim and compaction retry approximations If per-zone LRU accounting is available then there is no point approximating whether reclaim and compaction should retry based on pgdat statistics. This is effectively a revert of "mm, vmstat: remove zone and node double accounting by approximating retries" with the difference that inactive/active stats are still available. This preserves the history of why the approximation was retried and why it had to be reverted to handle OOM kills on 32-bit systems. Link: http://lkml.kernel.org/r/1469110261-7365-4-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Acked-by: Minchan Kim Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 222d5403dd4b..134381a20099 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -194,6 +194,24 @@ static bool sane_reclaim(struct scan_control *sc) } #endif +/* + * This misses isolated pages which are not accounted for to save counters. + * As the data only determines if reclaim or compaction continues, it is + * not expected that isolated pages will be a dominating factor. + */ +unsigned long zone_reclaimable_pages(struct zone *zone) +{ + unsigned long nr; + + nr = zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_FILE) + + zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_FILE); + if (get_nr_swap_pages() > 0) + nr += zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_ANON) + + zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_ANON); + + return nr; +} + unsigned long pgdat_reclaimable_pages(struct pglist_data *pgdat) { unsigned long nr; -- cgit