Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750762AbVKWM5S (ORCPT ); Wed, 23 Nov 2005 07:57:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750764AbVKWM5R (ORCPT ); Wed, 23 Nov 2005 07:57:17 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:57323 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S1750762AbVKWM5O (ORCPT ); Wed, 23 Nov 2005 07:57:14 -0500 Date: Wed, 23 Nov 2005 18:24:40 +0530 From: Maneesh Soni To: Steven Rostedt Cc: Ingo Molnar , Greg KH , LKML Subject: Re: What protection does sysfs_readdir have with SMP/Preemption? Message-ID: <20051123125440.GE22714@in.ibm.com> Reply-To: maneesh@in.ibm.com References: <1132695202.13395.15.camel@localhost.localdomain> <20051122213947.GB8575@kroah.com> <20051123045049.GA22714@in.ibm.com> <20051123081845.GA32021@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.10i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1422 Lines: 40 On Wed, Nov 23, 2005 at 07:35:04AM -0500, Steven Rostedt wrote: > > On Wed, 23 Nov 2005, Ingo Molnar wrote: > > > > > note that Steven has a dual-core Athlon64 X2 system. Steven, do you get > > the crash even with maxcpus=1? > > > > Actually Ingo, this happened on my UP test machine, a 368MHz Pentium. > > But unfortunately, it so far only happened once, and I've been trying to > recreate it, with no success. The test that crashed it was running 10 > tasks that would read the entire filesystem. I was debugging another bug > (something specific to my kernel, or maybe -rt) when I hit this bug. > Looking at it, it seemed to not be related to the changes I made. Perhaps > it could be related to your changes? > I normally test the sysfs races by running these two loops simultenously on a SMP box. Basically running these will create/delete sysfs files and directories and also do readdir. while true; do insmod drivers/net/dummy.ko; rmmod dummy; done while true; do find /sys/class/net/dummy0/ | xargs cat > /dev/null; done -- Maneesh Soni Linux Technology Center, IBM India Software Labs, Bangalore, India email: maneesh@in.ibm.com Phone: 91-80-25044990 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/