Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967225Ab3E2XSS (ORCPT ); Wed, 29 May 2013 19:18:18 -0400 Received: from cantor2.suse.de ([195.135.220.15]:48070 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S967188Ab3E2XRs (ORCPT ); Wed, 29 May 2013 19:17:48 -0400 From: Mel Gorman To: Andrew Morton Cc: Jiri Slaby , Valdis Kletnieks , Rik van Riel , Zlatko Calusic , Johannes Weiner , dormando , Michal Hocko , Jan Kara , Dave Chinner , Kamezawa Hiroyuki , Linux-FSDevel , Linux-MM , LKML , Mel Gorman Subject: [PATCH 6/8] mm: vmscan: Treat pages marked for immediate reclaim as zone congestion Date: Thu, 30 May 2013 00:17:35 +0100 Message-Id: <1369869457-22570-7-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1369869457-22570-1-git-send-email-mgorman@suse.de> References: <1369869457-22570-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1625 Lines: 43 Currently a zone will only be marked congested if the underlying BDI is congested but if dirty pages are spread across zones it is possible that an individual zone is full of dirty pages without being congested. The impact is that zone gets scanned very quickly potentially reclaiming really clean pages. This patch treats pages marked for immediate reclaim as congested for the purposes of marking a zone ZONE_CONGESTED and stalling in wait_iff_congested. Signed-off-by: Mel Gorman --- mm/vmscan.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 4898daf..bf47784 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -761,9 +761,15 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (dirty && !writeback) nr_unqueued_dirty++; - /* Treat this page as congested if underlying BDI is */ + /* + * Treat this page as congested if the underlying BDI is or if + * pages are cycling through the LRU so quickly that the + * pages marked for immediate reclaim are making it to the + * end of the LRU a second time. + */ mapping = page_mapping(page); - if (mapping && bdi_write_congested(mapping->backing_dev_info)) + if ((mapping && bdi_write_congested(mapping->backing_dev_info)) || + (writeback && PageReclaim(page))) nr_congested++; /* -- 1.8.1.4 -- 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/