Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933997AbaLBTdM (ORCPT ); Tue, 2 Dec 2014 14:33:12 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49110 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932967AbaLBTdK (ORCPT ); Tue, 2 Dec 2014 14:33:10 -0500 Date: Tue, 2 Dec 2014 14:32:52 -0500 From: Dave Jones To: Chris Mason , Linus Torvalds , =?iso-8859-1?Q?D=E2niel?= Fraga , Sasha Levin , "Paul E. McKenney" , Linux Kernel Mailing List Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141202193252.GB17595@redhat.com> Mail-Followup-To: Dave Jones , Chris Mason , Linus Torvalds , =?iso-8859-1?Q?D=E2niel?= Fraga , Sasha Levin , "Paul E. McKenney" , Linux Kernel Mailing List References: <20141127225637.GA24019@redhat.com> <547b8a45.6e608c0a.20f9.1002@mx.google.com> <547bbe36.48548c0a.105c.779c@mx.google.com> <20141201191431.GA17385@linux.vnet.ibm.com> <547ccf74.a5198c0a.25de.26d9@mx.google.com> <20141201230339.GA20487@ret.masoncoding.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141201230339.GA20487@ret.masoncoding.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 Mon, Dec 01, 2014 at 06:08:38PM -0500, Chris Mason wrote: > I'm not sure if this is related, but running trinity here, I noticed it > was stuck at 100% system time on every CPU. perf report tells me we are > spending all of our time in spin_lock under the sync system call. > > I think it's coming from contention in the bdi_queue_work() call from > inside sync_inodes_sb, which is spin_lock_bh(). > > I wonder if we're just spinning so hard on this one bh lock that we're > starving the watchdog? > > Dave, do you have spinlock debugging on? That has been a constant, yes. I can try with that disabled some time. 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/