From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758125AbYE0Nf0 (ORCPT ); Tue, 27 May 2008 09:35:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757277AbYE0NfO (ORCPT ); Tue, 27 May 2008 09:35:14 -0400 Received: from brick.kernel.dk ([87.55.233.238]:16317 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757406AbYE0NfN (ORCPT ); Tue, 27 May 2008 09:35:13 -0400 Date: Tue, 27 May 2008 15:35:10 +0200 From: Jens Axboe To: Alexey Dobriyan Cc: torvalds@osdl.org, Andrew Morton , linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com Subject: Re: 2.6.26-rc4: RIP __call_for_each_cic+0x20/0x50 Message-ID: <20080527133510.GV7712@kernel.dk> References: <20080428050145.af036c4f.akpm@linux-foundation.org> <20080428120412.GY12774@kernel.dk> <20080428195509.GA5247@martell.zuzino.mipt.ru> <20080429062116.GA5059@martell.zuzino.mipt.ru> <20080429090604.GK12774@kernel.dk> <20080430221250.GA10150@martell.zuzino.mipt.ru> <20080504190811.GP12774@kernel.dk> <20080504201542.GA1040@martell.zuzino.mipt.ru> <20080510103719.GA4967@martell.zuzino.mipt.ru> <20080527052740.GB28301@martell.zuzino.mipt.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080527052740.GB28301@martell.zuzino.mipt.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 27 2008, Alexey Dobriyan wrote: > On Sat, May 10, 2008 at 02:37:19PM +0400, Alexey Dobriyan wrote: > > > > > > @@ -41,8 +41,8 @@ int put_io_context(struct io_context *ioc) > > > > > > rcu_read_lock(); > > > > > > if (ioc->aic && ioc->aic->dtor) > > > > > > ioc->aic->dtor(ioc->aic); > > > > > > - rcu_read_unlock(); > > > > > > cfq_dtor(ioc); > > > > > > + rcu_read_unlock(); > > > > > > > > > > > > kmem_cache_free(iocontext_cachep, ioc); > > > > > > return 1; > > > > > > > > > > This helps in sense that 3 times bulk cross-compiles finish to the end. > > > > > You'll hear me if another such oops will resurface. > > > > > > > > Still looking good? > > > > > > Yup! > > > > And this with patch in mainline, again with PREEMPT_RCU. > > Ping, this happened again with 2.6.26-rc4 and PREEMPT_RCU. Worrisome... Paul, would you mind taking a quick look at cfq and see if you can detect why breaks with preempt rcu? It's clearly a use-after-free symptom, but I don't see how it can happen. -- Jens Axboe