Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752633AbbHTNpa (ORCPT ); Thu, 20 Aug 2015 09:45:30 -0400 Received: from outbound-smtp03.blacknight.com ([81.17.249.16]:41186 "EHLO outbound-smtp03.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752499AbbHTNp3 (ORCPT ); Thu, 20 Aug 2015 09:45:29 -0400 Date: Thu, 20 Aug 2015 14:45:26 +0100 From: Mel Gorman To: Michal Hocko Cc: Linux-MM , Johannes Weiner , Rik van Riel , Vlastimil Babka , David Rientjes , Joonsoo Kim , LKML Subject: Re: [PATCH 03/10] mm, page_alloc: Remove unnecessary recalculations for dirty zone balancing Message-ID: <20150820134526.GD12432@techsingularity.net> References: <1439376335-17895-1-git-send-email-mgorman@techsingularity.net> <1439376335-17895-4-git-send-email-mgorman@techsingularity.net> <20150820124526.GE20110@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20150820124526.GE20110@dhcp22.suse.cz> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1096 Lines: 28 On Thu, Aug 20, 2015 at 02:45:27PM +0200, Michal Hocko wrote: > On Wed 12-08-15 11:45:28, Mel Gorman wrote: > > File-backed pages that will be immediately are balanced between zones but > ^written to... > > > it's unnecessarily expensive. > > to do WHAT? I guess you meant checking gfp_mask resp. alloc_mask? I > doubt it would make a noticeable difference as this is a slow path > already but I agree it doesn't make sense to check it again. > File-backed pages that will be immediately written are balanced between zones. This heuristic tries to avoid having a single zone filled with recently dirtied pages but the checks are unnecessarily expensive. Move consider_zone_balanced into the alloc_context instead of checking bitmaps multiple times. The patch also gives the parameter a more meaningful name. ? -- Mel Gorman SUSE Labs -- 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/