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 6B39E6B003D for ; Tue, 28 Apr 2009 04:17:00 -0400 (EDT) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e38.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n3S8EhnE030266 for ; Tue, 28 Apr 2009 02:14:43 -0600 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n3S8HE4q084076 for ; Tue, 28 Apr 2009 02:17:14 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n3S8HE3t002238 for ; Tue, 28 Apr 2009 02:17:14 -0600 Subject: Re: meminfo Committed_AS underflows From: Dave Hansen In-Reply-To: <20090427202707.9d36ce8a.akpm@linux-foundation.org> References: <20090415084713.GU7082@balbir.in.ibm.com> <20090427132722.926b07f1.akpm@linux-foundation.org> <20090428092400.EBB6.A69D9226@jp.fujitsu.com> <20090427202707.9d36ce8a.akpm@linux-foundation.org> Content-Type: text/plain Date: Tue, 28 Apr 2009 01:17:11 -0700 Message-Id: <1240906631.29485.75.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: KOSAKI Motohiro , balbir@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, ebmunson@us.ibm.com, mel@linux.vnet.ibm.com, cl@linux-foundation.org, stable@kernel.org List-ID: On Mon, 2009-04-27 at 20:27 -0700, Andrew Morton wrote: > There's potential here for weird performance regressions, so I think > that if we do this in mainline, we should wait a while (a few weeks?) > before backporting it. > > Do we know how long this bug has existed for? Quite a while, I > expect? Yeah, we didn't notice it until a recent enterprise distro got a config with NR_CPUS=1024. That opened the window up in a major way because of the way we calculated the threshold. -- Dave -- 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