diff mbox series

[5/5] mm: compaction: drop redundant watermark check in compaction_zonelist_suitable()

Message ID 20230519123959.77335-6-hannes@cmpxchg.org
State New
Headers
Series mm: compaction: cleanups & simplifications |

Commit Message

Johannes Weiner May 19, 2023, 12:39 p.m. UTC 
  The watermark check in compaction_zonelist_suitable(), called from
should_compact_retry(), is sandwiched between two watermark checks
already: before, there are freelist attempts as part of direct reclaim
and direct compaction; after, there is a last-minute freelist attempt
in __alloc_pages_may_oom().

The check in compaction_zonelist_suitable() isn't necessary. Kill it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 mm/compaction.c | 7 -------
 1 file changed, 7 deletions(-)

Comments

Vlastimil Babka May 29, 2023, 5:12 p.m. UTC | #1 
On 5/19/23 14:39, Johannes Weiner wrote:
> The watermark check in compaction_zonelist_suitable(), called from
> should_compact_retry(), is sandwiched between two watermark checks
> already: before, there are freelist attempts as part of direct reclaim
> and direct compaction; after, there is a last-minute freelist attempt
> in __alloc_pages_may_oom().
> 
> The check in compaction_zonelist_suitable() isn't necessary. Kill it.
> 
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

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

Patch

diff --git a/mm/compaction.c b/mm/compaction.c
index 83ecbc829c62..40ce4e6dd17e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2291,13 +2291,6 @@  bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
 	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist,
 				ac->highest_zoneidx, ac->nodemask) {
 		unsigned long available;
-		unsigned long watermark;
-
-		/* Allocation can already succeed, nothing to do */
-		watermark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
-		if (zone_watermark_ok(zone, order, watermark,
-				      ac->highest_zoneidx, alloc_flags))
-			continue;
 
 		/*
 		 * Do not consider all the reclaimable memory because we do not