From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754114Ab0JAGBl (ORCPT ); Fri, 1 Oct 2010 02:01:41 -0400 Received: from gate.crashing.org ([63.228.1.57]:60103 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753254Ab0JAGBj (ORCPT ); Fri, 1 Oct 2010 02:01:39 -0400 Subject: Re: Odd NFS related SIGBUS (& possible fix) From: Benjamin Herrenschmidt To: Nick Piggin Cc: Trond Myklebust , "linux-kernel@vger.kernel.org" , Al Viro , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org In-Reply-To: <1285912667.2463.68.camel@pasglop> References: <1285734825.14081.87.camel@pasglop> <1285912667.2463.68.camel@pasglop> Content-Type: text/plain; charset="UTF-8" Date: Fri, 01 Oct 2010 16:01:30 +1000 Message-ID: <1285912890.2463.71.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-10-01 at 15:57 +1000, Benjamin Herrenschmidt wrote: > I actually just reproduced the lockup on x86_64 with 4 CPUs using > mmapstress01 -p 5 -t 1.3 -f 4096. > > So the trick is to mount /tmp over nfs (so that the mmap'ed file ends up > on nfs) and run mmapstress01 as above. Then try ctrl-C it. > > I'll do a bz for that one. > > I'm now going to try going back kernel versions to see if I can also > reproduce the SIGBUS or other timing issues. So on x86 I didn't get a backtrace, but the VGA console was still responsive somewhat, and I saw mmapstress01 there using 100% CPU and unresponsive to kill -9 (stays in state R). Cheers, Ben.