When kswapd wakes up, it reads its order and classzone from pgdat and calls balance_pgdat. While its awake, it potentially reclaimes at a high order and a low classzone index. This might have been a once-off that was not required by subsequent callers. However, because the pgdat values were not reset, they remain artifically high while balance_pgdat() is running and potentially kswapd enters a second unnecessary reclaim cycle. Reset the pgdat order and classzone index after reading. Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> --- mm/vmscan.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 4d968b0..e1be4e8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2646,6 +2646,8 @@ static int kswapd(void *p) kswapd_try_to_sleep(pgdat, order); order = pgdat->kswapd_max_order; classzone_idx = pgdat->classzone_idx; + pgdat->kswapd_max_order = 0; + pgdat->classzone_idx = MAX_NR_ZONES - 1; } ret = try_to_freeze(); -- 1.7.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>