[PATCH 21/25] mm, page_alloc: Defer zlc_setup until it is known it is required

From: Mel Gorman
Date: Mon Jun 08 2015 - 09:58:38 EST


The zonelist cache (zlc) records if zone_reclaim() is necessary but it is
setup before it is checked if zone_reclaim is even enabled. This patch
defers the setup until after zone_reclaim is checked.

Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
mm/page_alloc.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6b3a78420a5e..637b293cd5d1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2076,6 +2076,10 @@ zonelist_scan:
if (alloc_flags & ALLOC_NO_WATERMARKS)
goto try_this_zone;

+ if (zone_reclaim_mode == 0 ||
+ !zone_allows_reclaim(ac->preferred_zone, zone))
+ goto this_zone_full;
+
if (IS_ENABLED(CONFIG_NUMA) &&
!did_zlc_setup && nr_online_nodes > 1) {
/*
@@ -2088,10 +2092,6 @@ zonelist_scan:
did_zlc_setup = 1;
}

- if (zone_reclaim_mode == 0 ||
- !zone_allows_reclaim(ac->preferred_zone, zone))
- goto this_zone_full;
-
/*
* As we may have just activated ZLC, check if the first
* eligible zone has failed zone_reclaim recently.
--
2.3.5

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