Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932497Ab3COUxi (ORCPT ); Fri, 15 Mar 2013 16:53:38 -0400 Received: from mail-lb0-f179.google.com ([209.85.217.179]:58449 "EHLO mail-lb0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754258Ab3COUxh (ORCPT ); Fri, 15 Mar 2013 16:53:37 -0400 MIME-Version: 1.0 In-Reply-To: <20130315203123.GA28128@kroah.com> References: <20130315132607.GA4565@quad> <20130315203123.GA28128@kroah.com> Date: Fri, 15 Mar 2013 14:53:35 -0600 Message-ID: Subject: Re: [PATCH] perf,x86: fix kernel crash with PEBS/BTS after suspend/resume From: Shuah Khan To: Greg KH Cc: Stephane Eranian , linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, mingo@elte.hu, tglx@linutronix.de, akpm@linux-foundation.org, acme@redhat.com, jolsa@redhat.com, ak@linux.intel.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1335 Lines: 33 On Fri, Mar 15, 2013 at 2:31 PM, Greg KH wrote: > On Fri, Mar 15, 2013 at 02:26:07PM +0100, Stephane Eranian wrote: >> >> This patch fixes a kernel crash when using precise sampling (PEBS) >> after a suspend/resume. Turns out the CPU notifier code is not invoked >> on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly >> by the kernel and keeps it power-on/resume value of 0 causing any PEBS >> measurement to crash when running on CPU0. >> >> The workaround is to add a hook in the actual resume code to restore >> the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0, >> the DS_AREA will be restored twice but this is harmless. >> >> Reported-by: Linus Torvalds >> Signed-off-by: Stephane Eranian >> --- > > Is this needed for the 3.8 or older kernels as well? > > thanks, > > greg k-h Just about to ask the same question. Patch applies to 3.8, 3.4, 3.2 and 3.5. But needs some massaging for 3.0. I have the kernels built, haven't started testing yet. -- Shuah -- 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/