From bb0b6dffa2ccfbd9747ad0cc87c7459622896e60 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 6 Aug 2014 16:07:18 -0700 Subject: [PATCH] mm: vmscan: only update per-cpu thresholds for online CPU When kswapd is awake reclaiming, the per-cpu stat thresholds are lowered to get more accurate counts to avoid breaching watermarks. This threshold update iterates over all possible CPUs which is unnecessary. Only online CPUs need to be updated. If a new CPU is onlined, refresh_zone_stat_thresholds() will set the thresholds correctly. Signed-off-by: Mel Gorman Acked-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmstat.c b/mm/vmstat.c index e574e883fa70..e9ab104b956f 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -200,7 +200,7 @@ void set_pgdat_percpu_threshold(pg_data_t *pgdat, continue; threshold = (*calculate_pressure)(zone); - for_each_possible_cpu(cpu) + for_each_online_cpu(cpu) per_cpu_ptr(zone->pageset, cpu)->stat_threshold = threshold; }