Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755874AbaLHQer (ORCPT ); Mon, 8 Dec 2014 11:34:47 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:48238 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482AbaLHQeq (ORCPT ); Mon, 8 Dec 2014 11:34:46 -0500 Message-ID: <5485D316.9080001@oracle.com> Date: Mon, 08 Dec 2014 11:34:30 -0500 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: Linus Torvalds , Dave Jones , Chris Mason , =?windows-1252?Q?D=E2niel_Fraga?= , Linux Kernel Mailing List Subject: Re: frequent lockups in 3.18rc4 References: <5481C92E.6020805@oracle.com> <54846B06.8050906@oracle.com> <20141207182420.GG25340@linux.vnet.ibm.com> <20141207194304.GA17810@linux.vnet.ibm.com> <5484E2AB.1070503@oracle.com> <20141208052048.GJ25340@linux.vnet.ibm.com> <5485B6B9.7010800@oracle.com> <5485C3B5.4000401@oracle.com> <20141208155745.GM25340@linux.vnet.ibm.com> In-Reply-To: <20141208155745.GM25340@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/08/2014 10:57 AM, Paul E. McKenney wrote: > On Mon, Dec 08, 2014 at 10:28:53AM -0500, Sasha Levin wrote: >> > On 12/08/2014 09:33 AM, Sasha Levin wrote: >>> > > On 12/08/2014 12:20 AM, Paul E. McKenney wrote: >>>>> > >> > I have seen this caused by lost IPIs, but you have to lose two of them, >>>>> > >> > which seems less than fully likely. >>> > > It does seem that it can cause full blown stalls as well, just pretty >>> > > rarely (notice the lack of any prints before): >> > >> > Forgot to mentioned, I cranked the rcu lockup timeout to 300 seconds and got >> > that stall. > So with the default of 21 seconds, you presumably get huge numbers of > RCU CPU stall warnings? Yes, I'm seeing 1 lockup every ~5 minutes on my set up. The traces do seem to be different every time. Thanks, Sasha -- 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/