From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 78C136B0005 for ; Fri, 17 Jun 2016 08:04:02 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id r190so8911667wmr.0 for ; Fri, 17 Jun 2016 05:04:02 -0700 (PDT) Received: from outbound-smtp08.blacknight.com (outbound-smtp08.blacknight.com. [46.22.139.13]) by mx.google.com with ESMTPS id 137si6265805wms.63.2016.06.17.05.04.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 17 Jun 2016 05:04:01 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp08.blacknight.com (Postfix) with ESMTPS id CE35A1C2A6F for ; Fri, 17 Jun 2016 13:04:00 +0100 (IST) Date: Fri, 17 Jun 2016 13:03:59 +0100 From: Mel Gorman Subject: Re: [PATCH 21/27] mm, vmscan: Only wakeup kswapd once per node for the requested classzone Message-ID: <20160617120301.GM1868@techsingularity.net> References: <1465495483-11855-1-git-send-email-mgorman@techsingularity.net> <1465495483-11855-22-git-send-email-mgorman@techsingularity.net> <2ce07fcf-7b7d-a70b-ed7b-60867ad4458f@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <2ce07fcf-7b7d-a70b-ed7b-60867ad4458f@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Vlastimil Babka Cc: Andrew Morton , Linux-MM , Rik van Riel , Johannes Weiner , LKML On Fri, Jun 17, 2016 at 12:46:05PM +0200, Vlastimil Babka wrote: > On 06/09/2016 08:04 PM, Mel Gorman wrote: > >kswapd is woken when zones are below the low watermark but the wakeup > >decision is not taking the classzone into account. Now that reclaim is > >node-based, it is only required to wake kswapd once per node and only if > >all zones are unbalanced for the requested classzone. > > > >Note that one node might be checked multiple times but there is no cheap > >way of tracking what nodes have already been visited for zoneslists that > >be ordered by either zone or node. > > Wouldn't it be possible to optimize for node order as you did in direct > reclaim? Do the zone_balanced checks when going through zonelist, and once > node changes in iteration, wake up if no eligible zones visited so far were > balanced. > Yeah, it is. I'll chuck it in. -- Mel Gorman SUSE Labs -- 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