From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 001356B008A for ; Thu, 14 Jan 2010 01:33:12 -0500 (EST) Received: from wpaz17.hot.corp.google.com (wpaz17.hot.corp.google.com [172.24.198.81]) by smtp-out.google.com with ESMTP id o0E6X7YB004557 for ; Thu, 14 Jan 2010 06:33:08 GMT Received: from pzk8 (pzk8.prod.google.com [10.243.19.136]) by wpaz17.hot.corp.google.com with ESMTP id o0E6Wcqb009312 for ; Wed, 13 Jan 2010 22:33:06 -0800 Received: by pzk8 with SMTP id 8so802119pzk.8 for ; Wed, 13 Jan 2010 22:33:06 -0800 (PST) Date: Wed, 13 Jan 2010 22:33:03 -0800 (PST) From: David Rientjes Subject: Re: [resend][PATCH] mm: Restore zone->all_unreclaimable to independence word In-Reply-To: <20100114103332.D71B.A69D9226@jp.fujitsu.com> Message-ID: References: <20100114103332.D71B.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , KAMEZAWA Hiroyuki , Minchan Kim , Wu Fengguang , Huang Shijie List-ID: On Thu, 14 Jan 2010, KOSAKI Motohiro wrote: > commit e815af95 (change all_unreclaimable zone member to flags) chage > all_unreclaimable member to bit flag. but It have undesireble side > effect. > free_one_page() is one of most hot path in linux kernel and increasing > atomic ops in it can reduce kernel performance a bit. > > Thus, this patch revert such commit partially. at least > all_unreclaimable shouldn't share memory word with other zone flags. > I still think you need to quantify this; saying you don't have a large enough of a machine that will benefit from it isn't really a rationale for the lack of any data supporting your claim. We should be basing VM changes on data, not on speculation that there's a measurable impact here. Perhaps you could ask a colleague or another hacker to run a benchmark for you so that the changelog is complete? -- 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