From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932302AbcGAUGc (ORCPT ); Fri, 1 Jul 2016 16:06:32 -0400 Received: from outbound-smtp11.blacknight.com ([46.22.139.16]:43077 "EHLO outbound-smtp11.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752732AbcGAUG3 (ORCPT ); Fri, 1 Jul 2016 16:06:29 -0400 From: Mel Gorman To: Andrew Morton , Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML , Mel Gorman Subject: [PATCH 27/31] mm: page_alloc: cache the last node whose dirty limit is reached Date: Fri, 1 Jul 2016 21:01:35 +0100 Message-Id: <1467403299-25786-28-git-send-email-mgorman@techsingularity.net> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> References: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a page is about to be dirtied then the page allocator attempts to limit the total number of dirty pages that exists in any given zone. The call to node_dirty_ok is expensive so this patch records if the last pgdat examined hit the dirty limits. In some cases, this reduces the number of calls to node_dirty_ok(). Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka --- mm/page_alloc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d4815a30965b..69ffaadc31ed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2891,6 +2891,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, { struct zoneref *z = ac->preferred_zoneref; struct zone *zone; + struct pglist_data *last_pgdat_dirty_limit = NULL; + /* * Scan zonelist, looking for a zone with enough free. * See also __cpuset_node_allowed() comment in kernel/cpuset.c. @@ -2923,8 +2925,15 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, * will require awareness of nodes in the * dirty-throttling and the flusher threads. */ - if (ac->spread_dirty_pages && !node_dirty_ok(zone->zone_pgdat)) - continue; + if (ac->spread_dirty_pages) { + if (last_pgdat_dirty_limit == zone->zone_pgdat) + continue; + + if (!node_dirty_ok(zone->zone_pgdat)) { + last_pgdat_dirty_limit = zone->zone_pgdat; + continue; + } + } mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; if (!zone_watermark_fast(zone, order, mark, -- 2.6.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f69.google.com (mail-lf0-f69.google.com [209.85.215.69]) by kanga.kvack.org (Postfix) with ESMTP id A9972828E1 for ; Fri, 1 Jul 2016 16:06:28 -0400 (EDT) Received: by mail-lf0-f69.google.com with SMTP id l184so87561786lfl.3 for ; Fri, 01 Jul 2016 13:06:28 -0700 (PDT) Received: from outbound-smtp06.blacknight.com (outbound-smtp06.blacknight.com. [81.17.249.39]) by mx.google.com with ESMTPS id r129si2335888wma.1.2016.07.01.13.06.27 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 01 Jul 2016 13:06:27 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail04.blacknight.ie [81.17.254.17]) by outbound-smtp06.blacknight.com (Postfix) with ESMTPS id 419C398D17 for ; Fri, 1 Jul 2016 20:06:27 +0000 (UTC) From: Mel Gorman Subject: [PATCH 27/31] mm: page_alloc: cache the last node whose dirty limit is reached Date: Fri, 1 Jul 2016 21:01:35 +0100 Message-Id: <1467403299-25786-28-git-send-email-mgorman@techsingularity.net> In-Reply-To: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> References: <1467403299-25786-1-git-send-email-mgorman@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Linux-MM Cc: Rik van Riel , Vlastimil Babka , Johannes Weiner , LKML , Mel Gorman If a page is about to be dirtied then the page allocator attempts to limit the total number of dirty pages that exists in any given zone. The call to node_dirty_ok is expensive so this patch records if the last pgdat examined hit the dirty limits. In some cases, this reduces the number of calls to node_dirty_ok(). Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka --- mm/page_alloc.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d4815a30965b..69ffaadc31ed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2891,6 +2891,8 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, { struct zoneref *z = ac->preferred_zoneref; struct zone *zone; + struct pglist_data *last_pgdat_dirty_limit = NULL; + /* * Scan zonelist, looking for a zone with enough free. * See also __cpuset_node_allowed() comment in kernel/cpuset.c. @@ -2923,8 +2925,15 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, * will require awareness of nodes in the * dirty-throttling and the flusher threads. */ - if (ac->spread_dirty_pages && !node_dirty_ok(zone->zone_pgdat)) - continue; + if (ac->spread_dirty_pages) { + if (last_pgdat_dirty_limit == zone->zone_pgdat) + continue; + + if (!node_dirty_ok(zone->zone_pgdat)) { + last_pgdat_dirty_limit = zone->zone_pgdat; + continue; + } + } mark = zone->watermark[alloc_flags & ALLOC_WMARK_MASK]; if (!zone_watermark_fast(zone, order, mark, -- 2.6.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org