Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751103AbZL1Hr1 (ORCPT ); Mon, 28 Dec 2009 02:47:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750858AbZL1Hr0 (ORCPT ); Mon, 28 Dec 2009 02:47:26 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:42336 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794AbZL1HrZ (ORCPT ); Mon, 28 Dec 2009 02:47:25 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: LKML , linux-mm , Andrew Morton , Balbir Singh , Mel Gorman , KAMEZAWA Hiroyuki Subject: [PATCH 1/4] vmstat: remove zone->lock from walk_zones_in_node Cc: kosaki.motohiro@jp.fujitsu.com Message-Id: <20091228164451.A687.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Mon, 28 Dec 2009 16:47:22 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2180 Lines: 72 The zone->lock is one of performance critical locks. Then, it shouldn't be hold for long time. Currently, we have four walk_zones_in_node() usage and almost use-case don't need to hold zone->lock. Thus, this patch move locking responsibility from walk_zones_in_node to its sub function. Also this patch kill unnecessary zone->lock taking. Cc: Mel Gorman Signed-off-by: KOSAKI Motohiro --- mm/vmstat.c | 8 +++++--- 1 files changed, 5 insertions(+), 3 deletions(-) diff --git a/mm/vmstat.c b/mm/vmstat.c index 6051fba..a5d45bc 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -418,15 +418,12 @@ static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, { struct zone *zone; struct zone *node_zones = pgdat->node_zones; - unsigned long flags; for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { if (!populated_zone(zone)) continue; - spin_lock_irqsave(&zone->lock, flags); print(m, pgdat, zone); - spin_unlock_irqrestore(&zone->lock, flags); } } @@ -455,6 +452,7 @@ static void pagetypeinfo_showfree_print(struct seq_file *m, pg_data_t *pgdat, struct zone *zone) { int order, mtype; + unsigned long flags; for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { seq_printf(m, "Node %4d, zone %8s, type %12s ", @@ -468,8 +466,11 @@ static void pagetypeinfo_showfree_print(struct seq_file *m, area = &(zone->free_area[order]); + spin_lock_irqsave(&zone->lock, flags); list_for_each(curr, &area->free_list[mtype]) freecount++; + spin_unlock_irqrestore(&zone->lock, flags); + seq_printf(m, "%6lu ", freecount); } seq_putc(m, '\n'); @@ -709,6 +710,7 @@ static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, struct zone *zone) { int i; + seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name); seq_printf(m, "\n pages free %lu" -- 1.6.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/