Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932600AbaJWSkg (ORCPT ); Thu, 23 Oct 2014 14:40:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13476 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932490AbaJWSkf (ORCPT ); Thu, 23 Oct 2014 14:40:35 -0400 Date: Thu, 23 Oct 2014 14:40:18 -0400 From: Dave Jones To: "Paul E. McKenney" Cc: Linux Kernel , htejun@gmail.com, oleg@redhat.com Subject: Re: rcu_preempt detected stalls. Message-ID: <20141023184018.GA12274@redhat.com> Mail-Followup-To: Dave Jones , "Paul E. McKenney" , Linux Kernel , htejun@gmail.com, oleg@redhat.com References: <20141013173504.GA27955@redhat.com> <20141023183232.GW4977@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141023183232.GW4977@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 23, 2014 at 11:32:32AM -0700, Paul E. McKenney wrote: > > trinity-c225 R running task 13448 646 32295 0x00000000 > > ffff880161ccfb28 0000000000000002 ffff880161ccfe10 ffff88000bf85e00 > > 00000000001d4100 0000000000000003 ffff880161ccffd8 00000000001d4100 > > ffff880030124680 ffff88000bf85e00 ffff880161ccffd8 0000000000000000 > > Call Trace: > > [] preempt_schedule_irq+0x52/0xb0 > > [] retint_kernel+0x20/0x30 > > [] ? __d_lookup_rcu+0xd1/0x1e0 > > [] ? __d_lookup_rcu+0x166/0x1e0 > > [] lookup_fast+0x4f/0x3d0 > > [] link_path_walk+0x1a7/0x8a0 > > [] ? path_lookupat+0x45/0x7b0 > > [] path_lookupat+0x67/0x7b0 > > [] ? trace_hardirqs_off+0xd/0x10 > > [] ? retint_restore_args+0xe/0xe > > [] filename_lookup+0x2b/0xc0 > > [] user_path_at_empty+0x67/0xc0 > > [] ? put_lock_stats.isra.27+0xe/0x30 > > [] ? lock_release_holdtime.part.28+0xe6/0x160 > > [] ? get_parent_ip+0xd/0x50 > > [] user_path_at+0x11/0x20 > > [] do_utimes+0xd1/0x180 > > [] SyS_utime+0x7f/0xc0 > > [] ? tracesys+0x7e/0xe2 > > [] tracesys+0xdd/0xe2 > > This one will require more looking. But did you do something like > create a pair of mutually recursive symlinks or something? ;-) I'm not 100% sure, but this may have been on a box that I was running tests on NFS. So maybe the server had disappeared with the mount still active.. Just a guess tbh. Dave -- 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/