Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751380AbaLEGia (ORCPT ); Fri, 5 Dec 2014 01:38:30 -0500 Received: from mail-qg0-f43.google.com ([209.85.192.43]:43305 "EHLO mail-qg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750998AbaLEGi3 (ORCPT ); Fri, 5 Dec 2014 01:38:29 -0500 MIME-Version: 1.0 In-Reply-To: <54813C03.8040009@oracle.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> <20141202193252.GB17595@redhat.com> <547E4C14.6040509@oracle.com> <54813C03.8040009@oracle.com> Date: Thu, 4 Dec 2014 22:38:28 -0800 X-Google-Sender-Auth: gbuijnAQ8TXopHc5SJ9SyE49eHI Message-ID: Subject: Re: frequent lockups in 3.18rc4 From: Linus Torvalds To: Sasha Levin Cc: Dave Jones , Chris Mason , =?UTF-8?Q?D=C3=A2niel_Fraga?= , "Paul E. McKenney" , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 4, 2014 at 9:00 PM, Sasha Levin wrote: > > Just to add to this: I've enabled the simplest level of verbosity in the fault > injection options, and RCU stalls are again easy to trigger: Where do you log to? In particular, do you have some serial line logging enabled (perhaps even without anybody listening)? Or network logging? We've definitely had cases where logging itself is so slow that it triggers watchdogs etc. Logging to a serial line can take for*ever* in modern terms.. Linus -- 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/