From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761313AbZD1IRc (ORCPT ); Tue, 28 Apr 2009 04:17:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757302AbZD1IRR (ORCPT ); Tue, 28 Apr 2009 04:17:17 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:44396 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760286AbZD1IRP (ORCPT ); Tue, 28 Apr 2009 04:17:15 -0400 Subject: Re: meminfo Committed_AS underflows From: Dave Hansen 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 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 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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