Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752505AbbHTOZd (ORCPT ); Thu, 20 Aug 2015 10:25:33 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:36443 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751210AbbHTOZb (ORCPT ); Thu, 20 Aug 2015 10:25:31 -0400 Date: Thu, 20 Aug 2015 16:25:29 +0200 From: Michal Hocko To: Mel Gorman 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: <20150820142529.GJ20110@dhcp22.suse.cz> References: <1439376335-17895-1-git-send-email-mgorman@techsingularity.net> <1439376335-17895-4-git-send-email-mgorman@techsingularity.net> <20150820124526.GE20110@dhcp22.suse.cz> <20150820134526.GD12432@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150820134526.GD12432@techsingularity.net> 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: 1201 Lines: 28 On Thu 20-08-15 14:45:26, Mel Gorman wrote: > 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. Sounds much better. Thanks! -- Michal Hocko 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/