From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f70.google.com (mail-wm0-f70.google.com [74.125.82.70]) by kanga.kvack.org (Postfix) with ESMTP id 7F3A5828E1 for ; Fri, 1 Jul 2016 11:42:35 -0400 (EDT) Received: by mail-wm0-f70.google.com with SMTP id r190so21611986wmr.0 for ; Fri, 01 Jul 2016 08:42:35 -0700 (PDT) Received: from outbound-smtp10.blacknight.com (outbound-smtp10.blacknight.com. [46.22.139.15]) by mx.google.com with ESMTPS id mb8si4035045wjb.202.2016.07.01.08.42.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Jul 2016 08:42:34 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail06.blacknight.ie [81.17.255.152]) by outbound-smtp10.blacknight.com (Postfix) with ESMTPS id 104C01C1F5B for ; Fri, 1 Jul 2016 16:42:34 +0100 (IST) From: Mel Gorman Subject: [PATCH 27/31] mm: page_alloc: cache the last node whose dirty limit is reached Date: Fri, 1 Jul 2016 16:37:42 +0100 Message-Id: <1467387466-10022-28-git-send-email-mgorman@techsingularity.net> In-Reply-To: <1467387466-10022-1-git-send-email-mgorman@techsingularity.net> References: <1467387466-10022-1-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(). Link: http://lkml.kernel.org/r/1466518566-30034-26-git-send-email-mgorman@techsingularity.net Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Johannes Weiner Cc: Rik van Riel Signed-off-by: Andrew Morton --- 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