[PATCH] mm/compaction.c: micro-optimization remove unnecessary branch

From: mateusznosek0
Date: Sun Sep 13 2020 - 15:06:06 EST


From: Mateusz Nosek <mateusznosek0@xxxxxxxxx>

The same code can work both for 'zone->compact_considered > defer_limit'
and 'zone->compact_considered >= defer_limit'. In the latter there is one
branch less which is more effective considering performance.

Signed-off-by: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
---
mm/compaction.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 176dcded298e..6c63844fc061 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -180,11 +180,10 @@ bool compaction_deferred(struct zone *zone, int order)
return false;

/* Avoid possible overflow */
- if (++zone->compact_considered > defer_limit)
+ if (++zone->compact_considered >= defer_limit) {
zone->compact_considered = defer_limit;
-
- if (zone->compact_considered >= defer_limit)
return false;
+ }

trace_mm_compaction_deferred(zone, order);

--
2.20.1