From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751128AbWF1Tt2 (ORCPT ); Wed, 28 Jun 2006 15:49:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751129AbWF1Tt2 (ORCPT ); Wed, 28 Jun 2006 15:49:28 -0400 Received: from smtp.osdl.org ([65.172.181.4]:10118 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751128AbWF1Tt1 (ORCPT ); Wed, 28 Jun 2006 15:49:27 -0400 Date: Wed, 28 Jun 2006 12:49:06 -0700 From: Andrew Morton To: Jeremy Fitzhardinge Cc: mbligh@google.com, mbligh@mbligh.org, linux-kernel@vger.kernel.org, apw@shadowen.org, linuxppc64-dev@ozlabs.org, drfickle@us.ibm.com Subject: Re: 2.6.17-mm2 Message-Id: <20060628124906.b289e80b.akpm@osdl.org> In-Reply-To: <44A2D6DA.1050607@goop.org> References: <449D5D36.3040102@google.com> <449FF3A2.8010907@mbligh.org> <44A150C9.7020809@mbligh.org> <20060628034215.c3008299.akpm@osdl.org> <20060628034748.018eecac.akpm@osdl.org> <44A29582.7050403@google.com> <20060628121102.638f08d9.akpm@osdl.org> <44A2D6DA.1050607@goop.org> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.17; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 28 Jun 2006 12:22:02 -0700 Jeremy Fitzhardinge wrote: > Andrew Morton wrote: > > Found a way to reproduce it - do `cat /proc/slabinfo > /dev/null' in a > > tight loop. With that happening, a little two-way wasn't able to make > > it through `dbench 4' without soiling the upholstery. Then bisection-searching. > > > It's surprising it was so subtle. I'd been running with that code for a > month or so without a peep of problem... > It'll only bite if someone does snprintf() into a too-short buffer. That's rare (it's usually a bug). But it looks like the seq_file() code does it when someone is trying to generate more than PAGE_SIZE's worth of data. Like /proc/slabinfo.