Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754268AbaLBONc (ORCPT ); Tue, 2 Dec 2014 09:13:32 -0500 Received: from mail-qa0-f47.google.com ([209.85.216.47]:58870 "EHLO mail-qa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbaLBONa (ORCPT ); Tue, 2 Dec 2014 09:13:30 -0500 Message-ID: <1417529606.3924.26.camel@maggy.simpson.net> Subject: Re: frequent lockups in 3.18rc4 From: Mike Galbraith To: Chris Mason Cc: Linus Torvalds , =?ISO-8859-1?Q?D=E2niel?= Fraga , Dave Jones , Sasha Levin , "Paul E. McKenney" , Linux Kernel Mailing List Date: Tue, 02 Dec 2014 07:13:26 -0700 In-Reply-To: <20141201230339.GA20487@ret.masoncoding.com> 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> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-12-01 at 18:08 -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? The bean counting problem below can contribute. https://lkml.org/lkml/2014/3/30/7 -Mike -- 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/