The patch titled
Subject: mm/compaction.c: micro-optimization remove unnecessary branch
has been added to the -mm tree. Its filename is
mm-compactionc-micro-optimization-remove-unnecessary-branch.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-compactionc-micro-optimization-remove-unnecessary-branch.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-compactionc-micro-optimization-remove-unnecessary-branch.patch
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------------------------------------------------------
From: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
Subject: mm/compaction.c: micro-optimization remove unnecessary branch
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.
Link: https://lkml.kernel.org/r/20200913190448.28649-1-mateusznosek0@xxxxxxxxx
Signed-off-by: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/mm/compaction.c~mm-compactionc-micro-optimization-remove-unnecessary-branch
+++ a/mm/compaction.c
@@ -180,11 +180,10 @@ bool compaction_deferred(struct zone *zo
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);
_
Patches currently in -mm which might be from mateusznosek0@xxxxxxxxx are
mm-page_allocc-clean-code-by-removing-unnecessary-initialization.patch
mm-page_allocc-micro-optimization-remove-unnecessary-branch.patch
mm-compactionc-micro-optimization-remove-unnecessary-branch.patch
