From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755472AbbLKLa7 (ORCPT ); Fri, 11 Dec 2015 06:30:59 -0500 Received: from casper.infradead.org ([85.118.1.10]:44250 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755112AbbLKLa5 (ORCPT ); Fri, 11 Dec 2015 06:30:57 -0500 Date: Fri, 11 Dec 2015 12:30:51 +0100 From: Peter Zijlstra To: Ross Green Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: Re: rcu_preempt self-detected stall on CPU from 4.4-rc4, since 3.17 Message-ID: <20151211113051.GH6356@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 11, 2015 at 10:17:33PM +1100, Ross Green wrote: > I have been getting these stalls in kernels going back to 3.17. > > This stall occurs usually under light load but often requires several > days to show itself. I have not found any simple way to trigger the > stall. Indeed heavy workloads seems not to show the fault. > > Anyone have any thoughts here? see lkml.kernel.org/r/564F3DCA.1080907@arm.com