The patch titled
Subject: mm: compaction: skip fast freepages isolation if enough freepages are isolated
has been added to the -mm mm-unstable branch. Its filename is
mm-compaction-skip-fast-freepages-isolation-if-enough-freepages-are-isolated.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-compaction-skip-fast-freepages-isolation-if-enough-freepages-are-isolated.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: compaction: skip fast freepages isolation if enough freepages are isolated
Date: Thu, 25 May 2023 20:54:01 +0800
I've observed that fast isolation often isolates more pages than
cc->migratepages, and the excess freepages will be released back to the
buddy system. So skip fast freepages isolation if enough freepages are
isolated to save some CPU cycles.
Link: https://lkml.kernel.org/r/f39c2c07f2dba2732fd9c0843572e5bef96f7f67.1685018752.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/mm/compaction.c~mm-compaction-skip-fast-freepages-isolation-if-enough-freepages-are-isolated
+++ a/mm/compaction.c
@@ -1558,6 +1558,10 @@ static void fast_isolate_freepages(struc
spin_unlock_irqrestore(&cc->zone->lock, flags);
+ /* Skip fast search if enough freepages isolated */
+ if (cc->nr_freepages >= cc->nr_migratepages)
+ break;
+
/*
* Smaller scan on next order so the total scan is related
* to freelist_scan_limit.
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-page_alloc-drop-the-unnecessary-pfn_valid-for-start-pfn.patch
mm-compaction-drop-the-redundant-page-validation-in-update_pageblock_skip.patch
mm-compaction-change-fast_isolate_freepages-to-void-type.patch
mm-compaction-skip-more-fully-scanned-pageblock.patch
mm-compaction-only-set-skip-flag-if-cc-no_set_skip_hint-is-false.patch
mm-compaction-add-trace-event-for-fast-freepages-isolation.patch
mm-compaction-skip-fast-freepages-isolation-if-enough-freepages-are-isolated.patch
