From: Mel Gorman <mgorman@suse.de>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Rik van Riel <riel@redhat.com>, Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>, Mel Gorman <mgorman@suse.de>
Subject: [PATCH 3/4] mm: page_alloc: Use zone node IDs to approximate locality
Date: Thu, 12 Dec 2013 15:06:18 +0000 [thread overview]
Message-ID: <1386860779-2301-4-git-send-email-mgorman@suse.de> (raw)
In-Reply-To: <1386860779-2301-1-git-send-email-mgorman@suse.de>
zone_local is using node_distance which is a more expensive call than
necessary. On x86, it's another function call in the allocator fast path
and increases cache footprint. This patch makes the assumption zones on a
local node will share the same node ID. The necessary information should
already be cache hot.
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/page_alloc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 64020eb..fd9677e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1816,7 +1816,7 @@ static void zlc_clear_zones_full(struct zonelist *zonelist)
static bool zone_local(struct zone *local_zone, struct zone *zone)
{
- return node_distance(local_zone->node, zone->node) == LOCAL_DISTANCE;
+ return zone_to_nid(zone) == numa_node_id();
}
static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone)
--
1.8.4
next prev parent reply other threads:[~2013-12-12 15:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-12 15:06 [RFC PATCH 0/4] Configurable fair allocation zone policy Mel Gorman
2013-12-12 15:06 ` [PATCH 1/4] mm: page_alloc: exclude unreclaimable allocations from zone fairness policy Mel Gorman
2013-12-12 15:06 ` [PATCH 2/4] mm: page_alloc: Break out zone page aging distribution into its own helper Mel Gorman
2013-12-12 15:06 ` Mel Gorman [this message]
2013-12-12 15:06 ` [PATCH 4/4] mm: page_alloc: Make zone distribution page aging policy configurable Mel Gorman
2013-12-12 15:34 ` [RFC PATCH 0/4] Configurable fair allocation zone policy Mel Gorman
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