From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752012AbZINJ2f (ORCPT ); Mon, 14 Sep 2009 05:28:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750874AbZINJ2d (ORCPT ); Mon, 14 Sep 2009 05:28:33 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:2367 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbZINJ2d (ORCPT ); Mon, 14 Sep 2009 05:28:33 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:x-enigmail-version:content-type :content-transfer-encoding; b=xkVxxb7ojjkTFYnWC+8jVkNvIC+YSUmDlj2TmIV2+Zi0KAwnCNFy3JY6fnDlcfVPZC E4jVZXgGP3h8x9qRvk4Q+Pms/hWeuexGENe2a2p5C6eEqu26U15LyVUKt4dC4X3mlZ4L rgtJOe3wiaRfP4aUnOMH8c2WIOk4UgCchylpI= Message-ID: <4AAE0CC2.5010502@gmail.com> Date: Mon, 14 Sep 2009 11:28:34 +0200 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; cs-CZ; rv:1.9.1.1) Gecko/20090715 SUSE/3.0b3-8.6 Thunderbird/3.0b3 MIME-Version: 1.0 To: Thomas Gleixner CC: Linux kernel mailing list , Andrew Morton Subject: Re: clocksource: !keventd_up() && schedule_work() == oops References: <4AA760B6.6070601@gmail.com> In-Reply-To: <4AA760B6.6070601@gmail.com> X-Enigmail-Version: 0.97a Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/09/2009 10:00 AM, Jiri Slaby wrote: > Hi, > > I started to see oopses on boot in qemu machine because keventd is > created in kernel_init/do_basic_setup, but schedule_work is done earlier > in kernel_init/smp_init[1] when the tsc is unstable during this early phase. > > It looks like "clocksource: Resolve cpu hotplug dead lock with TSC > unstable" is the culprit. > > Creating its own either singlethread or "multithread" workqueue won't > work either (we do not have singlethread_cpu and cpu_populated_map). > Checking !keventd_up() in the clocksource code looks to me like a hack. > Any ideas, please? Still present in mmotm 2009-09-14-01-57. > [1] > kernel_init/smp_init/cpu_up/native_cpu_up/check_tsc_sync_source/mark_tsc_unstable/clocksource_mark_unstable/__clocksource_unstable