From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f171.google.com (mail-wi0-f171.google.com [209.85.212.171]) by kanga.kvack.org (Postfix) with ESMTP id 2E4056B0255 for ; Thu, 20 Aug 2015 09:45:30 -0400 (EDT) Received: by wicja10 with SMTP id ja10so146087664wic.1 for ; Thu, 20 Aug 2015 06:45:29 -0700 (PDT) Received: from outbound-smtp01.blacknight.com (outbound-smtp01.blacknight.com. [81.17.249.7]) by mx.google.com with ESMTPS id cn6si12736215wib.103.2015.08.20.06.45.28 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Thu, 20 Aug 2015 06:45:28 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp01.blacknight.com (Postfix) with ESMTPS id C70B7C8022 for ; Thu, 20 Aug 2015 13:45:27 +0000 (UTC) Date: Thu, 20 Aug 2015 14:45:26 +0100 From: Mel Gorman 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> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Linux-MM , Johannes Weiner , Rik van Riel , Vlastimil Babka , David Rientjes , Joonsoo Kim , LKML 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, 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