+ mm-compactionc-micro-optimization-remove-unnecessary-branch.patch added to -mm tree

[akpm@linux-foundation.org]

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@gmail.com>
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@gmail.com
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@gmail.com 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