Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1758795Ab3GZNPN (ORCPT <rfc822;w@1wt.eu>);
	Fri, 26 Jul 2013 09:15:13 -0400
Received: from mail-ob0-f181.google.com ([209.85.214.181]:50255 "EHLO
	mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1757038Ab3GZNPK (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 26 Jul 2013 09:15:10 -0400
MIME-Version: 1.0
In-Reply-To: <CAKb7Uvh+3BXkBjNkbfAQ=ginaoKyJj3+hNKL+WJ0XknAaZd==g@mail.gmail.com>
References: <CAKb7UvjQYeQjGsw4U_OrBuioF7KdVrBgCNmx5xi3aPXkPsTzaA@mail.gmail.com>
	<CAKb7Uvh+3BXkBjNkbfAQ=ginaoKyJj3+hNKL+WJ0XknAaZd==g@mail.gmail.com>
Date: Fri, 26 Jul 2013 09:15:09 -0400
X-Google-Sender-Auth: XtGxd7lIiwR_PX2_HnjBd6BwYTM
Message-ID: <CAKb7UvjYNz8KRnny8EB6rxQcLPrp0Y8CWHZaVG0qzAJisC8dog@mail.gmail.com>
Subject: Re: 3.11-rc2: panic in __rdmsr_on_cpu
From: Ilia Mirkin <imirkin@alum.mit.edu>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Zhang Rui <rui.zhang@intel.com>
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 2088
Lines: 59

On Fri, Jul 26, 2013 at 7:59 AM, Ilia Mirkin <imirkin@alum.mit.edu> wrote:
> On Thu, Jul 25, 2013 at 6:32 PM, Ilia Mirkin <imirkin@alum.mit.edu> wrote:
>> Hi,
>>
>> I just built a 3.11-rc2 kernel (+ a few patches, but nothing
>> arch-related), and I saw the following: http://i.imgur.com/dCTqOyR.jpg
>>
>> The rough transcription is
>>
>> Call Trace:
>> <IRQ>
>> generic_smp_call_fucntion_single_interrupt
>> smp_call_function_single_interrupt
>> call_function_single_interrupt
>> <EOI>
>> ? default_idle
>> ? default_idle
>> arch_cpu_idle
>> cpu_startup_entry
>> rest_init
>> start_kernel
>> ? repair_env_string
>> x86_64_start_reservations
>> x86_64_start_kernel
>> Code: ... cc 81 8b 0f <0f> 32 48 c1 e2 20 89 c0 ...
>> RIP: __rdmsr_on_cpu+0x2e/0x44
>> Kernel panic - not syncing: Fatal exception in interrupt
>>
>> A 3.10-rc7 kernel booted just fine. Is this likely a real issue? Or
>> perhaps a mis-build of some sort?
>
> FWIW this is repeatable. I did a clean build (make clean && make) and
> I still see the same thing. I have a Core i7-920 cpu, not sure what
> other information would be relevant. I'd love to avoid a bisect, so
> some likely candidates would be most welcome.

Aha, figured it out. I had enabled "X86 package temperature thermal
driver" = Y, which caused my Core i7-920 to produce the above trace on
boot. Glancing over the code, should this:

                if (!cpu_has(c, X86_FEATURE_DTHERM) &&
                                        !cpu_has(c, X86_FEATURE_PTS))
                        return -ENODEV;

perhaps be

                if (!cpu_has(c, X86_FEATURE_DTHERM) ||
                                        !cpu_has(c, X86_FEATURE_PTS))
                        return -ENODEV;

i.e. are both of those things required, or just one of them? My cpu
has DTHERM but not PTS, according to /proc/cpuinfo.

  -ilia
--
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/