Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753123AbcC0VHe (ORCPT ); Sun, 27 Mar 2016 17:07:34 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:47360 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752776AbcC0VHc (ORCPT ); Sun, 27 Mar 2016 17:07:32 -0400 X-IBM-Helo: d03dlp03.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org Date: Sun, 27 Mar 2016 14:07:33 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: Mathieu Desnoyers , "Chatre, Reinette" , Jacob Pan , Josh Triplett , Ross Green , John Stultz , Thomas Gleixner , lkml , Ingo Molnar , Lai Jiangshan , dipankar@in.ibm.com, Andrew Morton , rostedt , David Howells , Eric Dumazet , Darren Hart , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Oleg Nesterov , pranith kumar Subject: Re: rcu_preempt self-detected stall on CPU from 4.5-rc3, since 3.17 Message-ID: <20160327210733.GC4287@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <0D818C7A2259ED42912C1E04120FDE26712E676E@ORSMSX111.amr.corp.intel.com> <20160325214623.GR4287@linux.vnet.ibm.com> <1370753660.36931.1458995371427.JavaMail.zimbra@efficios.com> <20160326152816.GW4287@linux.vnet.ibm.com> <20160326184940.GA23851@linux.vnet.ibm.com> <706246733.37102.1459030977316.JavaMail.zimbra@efficios.com> <20160327013456.GX4287@linux.vnet.ibm.com> <702204510.37291.1459086535844.JavaMail.zimbra@efficios.com> <20160327154018.GA4287@linux.vnet.ibm.com> <20160327205318.GX6356@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160327205318.GX6356@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16032721-0009-0000-0000-0000199E08FB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 685 Lines: 17 On Sun, Mar 27, 2016 at 10:53:18PM +0200, Peter Zijlstra wrote: > On Sun, Mar 27, 2016 at 08:40:18AM -0700, Paul E. McKenney wrote: > > Oh, and the patch I am running with is below. I am running x86, and so > > some other architectures would of course need the corresponding patch > > on that architecture. > > > -#define TIF_POLLING_NRFLAG 21 /* idle is polling for TIF_NEED_RESCHED */ > > Also note that ARM (v7) which Ross is running doesn't have this to begin > with. He might well be seeing some other bug, then. Reinette might be instead seeing time-synchronization issues, perhaps that is also Ross's problem. Or maybe there is more than one bug. ;-) Thanx, Paul