From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f169.google.com (mail-wi0-f169.google.com [209.85.212.169]) by kanga.kvack.org (Postfix) with ESMTP id 3E6A46B0038 for ; Mon, 27 Apr 2015 04:08:55 -0400 (EDT) Received: by wiax7 with SMTP id x7so77978543wia.0 for ; Mon, 27 Apr 2015 01:08:54 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id di7si31970527wjc.113.2015.04.27.01.08.53 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 27 Apr 2015 01:08:53 -0700 (PDT) Date: Mon, 27 Apr 2015 09:08:50 +0100 From: Mel Gorman Subject: Re: [PATCH 1/3] mm/page_alloc: don't break highest order freepage if steal Message-ID: <20150427080850.GF2449@suse.de> References: <1430119421-13536-1-git-send-email-iamjoonsoo.kim@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1430119421-13536-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Vlastimil Babka , Johannes Weiner , Rik van Riel On Mon, Apr 27, 2015 at 04:23:39PM +0900, Joonsoo Kim wrote: > When we steal whole pageblock, we don't need to break highest order > freepage. Perhaps, there is small order freepage so we can use it. > The reason why the largest block is taken is to reduce the probability there will be another fallback event in the near future. Early on, there were a lot of tests conducted to measure the number of external fragmenting events and take steps to reduce them. Stealing the largest highest order freepage was one of those steps. -- 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