From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754736Ab3LQQsb (ORCPT ); Tue, 17 Dec 2013 11:48:31 -0500 Received: from cantor2.suse.de ([195.135.220.15]:60506 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754612Ab3LQQs2 (ORCPT ); Tue, 17 Dec 2013 11:48:28 -0500 From: Mel Gorman To: Johannes Weiner Cc: Andrew Morton , Dave Hansen , Rik van Riel , Linux-MM , LKML , Mel Gorman Subject: [PATCH 3/6] mm: page_alloc: Use zone node IDs to approximate locality Date: Tue, 17 Dec 2013 16:48:21 +0000 Message-Id: <1387298904-8824-4-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1387298904-8824-1-git-send-email-mgorman@suse.de> References: <1387298904-8824-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Acked-by: Rik van Riel --- 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