From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f53.google.com (mail-wm0-f53.google.com [74.125.82.53]) by kanga.kvack.org (Postfix) with ESMTP id 5547A6B027B for ; Wed, 6 Apr 2016 07:24:05 -0400 (EDT) Received: by mail-wm0-f53.google.com with SMTP id v188so19256258wme.1 for ; Wed, 06 Apr 2016 04:24:05 -0700 (PDT) Received: from outbound-smtp09.blacknight.com (outbound-smtp09.blacknight.com. [46.22.139.14]) by mx.google.com with ESMTPS id y186si3246007wmy.43.2016.04.06.04.24.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 06 Apr 2016 04:24:04 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail06.blacknight.ie [81.17.255.152]) by outbound-smtp09.blacknight.com (Postfix) with ESMTPS id 0610B1C1D64 for ; Wed, 6 Apr 2016 12:24:04 +0100 (IST) From: Mel Gorman Subject: [PATCH 25/27] mm: page_alloc: Cache the last node whose dirty limit is reached Date: Wed, 6 Apr 2016 12:22:14 +0100 Message-Id: <1459941736-3633-26-git-send-email-mgorman@techsingularity.net> In-Reply-To: <1459941736-3633-23-git-send-email-mgorman@techsingularity.net> References: <1459941736-3633-23-git-send-email-mgorman@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: 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 --- mm/page_alloc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 54cfe26dcc66..a6e6184d3e38 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2607,6 +2607,7 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags, struct zoneref *z; struct page *page = NULL; struct zone *zone; + struct pglist_data *last_pgdat_dirty_limit = NULL; /* * Scan zonelist, looking for a zone with enough free. @@ -2639,8 +2640,15 @@ 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_ok(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