From: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Subject: mm, vmscan: avoid passing in `remaining' unnecessarily to prepare_kswapd_sleep() As pointed out by Minchan Kim, the first call to prepare_kswapd_sleep() always passes in 0 for `remaining' and the second call can trivially check the parameter in advance. Suggested-by: Minchan Kim <minchan@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1467970510-21195-27-git-send-email-mgorman@xxxxxxxxxxxxxxxxxxx Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff -puN mm/vmscan.c~mm-vmscan-avoid-passing-in-remaining-unnecessarily-to-prepare_kswapd_sleep mm/vmscan.c --- a/mm/vmscan.c~mm-vmscan-avoid-passing-in-remaining-unnecessarily-to-prepare_kswapd_sleep +++ a/mm/vmscan.c @@ -3021,15 +3021,10 @@ static bool zone_balanced(struct zone *z * * Returns true if kswapd is ready to sleep */ -static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, long remaining, - int classzone_idx) +static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx) { int i; - /* If a direct reclaimer woke kswapd within HZ/10, it's premature */ - if (remaining) - return false; - /* * The throttled processes are normally woken up in balance_pgdat() as * soon as pfmemalloc_watermark_ok() is true. But there is a potential @@ -3244,7 +3239,7 @@ static void kswapd_try_to_sleep(pg_data_ prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE); /* Try to sleep for a short interval */ - if (prepare_kswapd_sleep(pgdat, reclaim_order, remaining, classzone_idx)) { + if (prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) { /* * Compaction records what page blocks it recently failed to * isolate pages from and skips them in the future scanning. @@ -3279,7 +3274,8 @@ static void kswapd_try_to_sleep(pg_data_ * After a short sleep, check if it was a premature sleep. If not, then * go fully to sleep until explicitly woken up. */ - if (prepare_kswapd_sleep(pgdat, reclaim_order, remaining, classzone_idx)) { + if (!remaining && + prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) { trace_mm_vmscan_kswapd_sleep(pgdat->node_id); /* _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
