Commit cfc51155 authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds

mm, vmscan: wake up all pfmemalloc-throttled processes at once

Kswapd in balance_pgdate() currently uses wake_up() on processes waiting
in throttle_direct_reclaim(), which only wakes up a single process.  This
might leave processes waiting for longer than necessary, until the check
is reached in the next loop iteration.  Processes might also be left
waiting if zone was fully balanced in single iteration.  Note that the
comment in balance_pgdat() also says "Wake them", so waking up a single
process does not seem intentional.

Thus, replace wake_up() with wake_up_all().
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: default avatarRik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 44628d97
...@@ -3175,7 +3175,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, ...@@ -3175,7 +3175,7 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order,
*/ */
if (waitqueue_active(&pgdat->pfmemalloc_wait) && if (waitqueue_active(&pgdat->pfmemalloc_wait) &&
pfmemalloc_watermark_ok(pgdat)) pfmemalloc_watermark_ok(pgdat))
wake_up(&pgdat->pfmemalloc_wait); wake_up_all(&pgdat->pfmemalloc_wait);
/* /*
* Fragmentation may mean that the system cannot be rebalanced * Fragmentation may mean that the system cannot be rebalanced
......
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