diff mbox series

[6/6] mm: compaction: skip fast freepages isolation if enough freepages are isolated

Message ID f39c2c07f2dba2732fd9c0843572e5bef96f7f67.1685018752.git.baolin.wang@linux.alibaba.com
State New
Headers
Series Misc cleanups and improvements for compaction |

Commit Message

Baolin Wang May 25, 2023, 12:54 p.m. UTC 
  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.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
---
 mm/compaction.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Vlastimil Babka May 30, 2023, 8:32 a.m. UTC | #1 
On 5/25/23 14:54, Baolin Wang wrote:
> 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.
> 
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

> ---
>  mm/compaction.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mm/compaction.c b/mm/compaction.c
> index eccec84dae82..3ade4c095ed2 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -1550,6 +1550,10 @@ static void fast_isolate_freepages(struct compact_control *cc)
>  
>  		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.
diff mbox series

Patch

diff --git a/mm/compaction.c b/mm/compaction.c
index eccec84dae82..3ade4c095ed2 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1550,6 +1550,10 @@  static void fast_isolate_freepages(struct compact_control *cc)
 
 		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.