From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933064AbcFOOXQ (ORCPT ); Wed, 15 Jun 2016 10:23:16 -0400 Received: from mx2.suse.de ([195.135.220.15]:34508 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932406AbcFOOXP (ORCPT ); Wed, 15 Jun 2016 10:23:15 -0400 Subject: Re: [PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes To: Mel Gorman , Andrew Morton , Linux-MM References: <1465495483-11855-1-git-send-email-mgorman@techsingularity.net> <1465495483-11855-7-git-send-email-mgorman@techsingularity.net> Cc: Rik van Riel , Johannes Weiner , LKML From: Vlastimil Babka Message-ID: <0973a4bd-ec85-b6f2-02a4-25b787675e01@suse.cz> Date: Wed, 15 Jun 2016 16:23:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <1465495483-11855-7-git-send-email-mgorman@techsingularity.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/09/2016 08:04 PM, Mel Gorman wrote: > Patch "mm: vmscan: Begin reclaiming pages on a per-node basis" started > thinking of reclaim in terms of nodes but kswapd is still zone-centric. This > patch gets rid of many of the node-based versus zone-based decisions. > > o A node is considered balanced when any eligible lower zone is balanced. > This eliminates one class of age-inversion problem because we avoid > reclaiming a newer page just because it's in the wrong zone > o pgdat_balanced disappears because we now only care about one zone being > balanced. > o Some anomalies related to writeback and congestion tracking being based on > zones disappear. > o kswapd no longer has to take care to reclaim zones in the reverse order > that the page allocator uses. > o Most importantly of all, reclaim from node 0 with multiple zones will > have similar aging and reclaiming characteristics as every > other node. > > Signed-off-by: Mel Gorman > Acked-by: Johannes Weiner Acked-by: Vlastimil Babka