Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754860AbYHZHBg (ORCPT ); Tue, 26 Aug 2008 03:01:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751686AbYHZHB2 (ORCPT ); Tue, 26 Aug 2008 03:01:28 -0400 Received: from yx-out-2324.google.com ([74.125.44.28]:20822 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752075AbYHZHB1 (ORCPT ); Tue, 26 Aug 2008 03:01:27 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=LVUWDuCjOhNOOPMS0wm3Nonc81ygPz9U9aTY75CEedSn03zA17Qasc+fb1qK3yQaDY 0EmUtyp7t5dDXleUQ2KgheKzBYs4vi4Cjann1smF1tg5evU4we1ynDBU3BfhrOwvHp2m EaRKy9cZT9LLvOH2y8dTH939XfNGu3/OMcFOk= Message-ID: <19f34abd0808260001h58077b04j4b174eeba184d70f@mail.gmail.com> Date: Tue, 26 Aug 2008 09:01:26 +0200 From: "Vegard Nossum" To: "Andrew Morton" Subject: Re: [-mmotm] BUG: scheduling while atomic: swapper Cc: "Ryan Hope" , LKML , "Ingo Molnar" , "Mike Travis" In-Reply-To: <20080825233729.816cf182.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <48f7fe350808251909g26207e7agdda6408c0b46a1ed@mail.gmail.com> <20080825233729.816cf182.akpm@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2358 Lines: 57 On Tue, Aug 26, 2008 at 8:37 AM, Andrew Morton wrote: > On Mon, 25 Aug 2008 22:09:25 -0400 "Ryan Hope" wrote: > >> BUG: scheduling while atomic: swapper/1/0x00000002 >> Modules linked in: >> Pid: 1, comm: swapper Tainted: G W 2.6.27-rc4-zenmmotm1 #4 >> [] schedule+0x287/0x6d0 >> [] vsnprintf+0x3a6/0x6c0 >> [] schedule_timeout+0x7d/0xb0 >> [] __wake_up+0x38/0x50 >> [] wait_for_common+0x8a/0x130 >> [] default_wake_function+0x0/0x10 >> [] call_usermodehelper_exec+0xc3/0xf0 >> [] kobject_uevent_env+0x37e/0x3a0 >> [] device_add+0x551/0x630 >> [] device_create_vargs+0xb3/0xd0 >> [] microcode_intel_module_init+0x0/0x39 >> [] device_create+0x2b/0x30 >> [] misc_register+0xbe/0x170 >> [] microcode_init+0x21/0xf0 >> [] do_one_initcall+0x26/0x170 >> [] __wake_up+0x38/0x50 >> [] insert_work+0x48/0x50 >> [] __queue_work+0x25/0x40 >> [] queue_work_on+0x3a/0x50 >> [] kernel_init+0x170/0x251 >> [] kernel_init+0x0/0x251 >> [] kernel_thread_helper+0x7/0x10 >> ======================= > > As a mad guess, I'd guess that someone changed get_online_cpus() so > that disables preemption (with a suitable config combination, perhaps). > Which would cause microcode_init()'s sysdev_driver_register() to run > in atomic context. > > But that's just a guess - I can't immediately see any change in there > which does this. Ingo, any theories? Looks like the kernel was W-tainted already... so likely there was a BUG or a WARNING even before this. And I think this sort of warning can happen if a(nother) process was killed while preemption was off (e.g. a BUG() at the wrong moment). Ryan? Vegard -- "The animistic metaphor of the bug that maliciously sneaked in while the programmer was not looking is intellectually dishonest as it disguises that the error is the programmer's own creation." -- E. W. Dijkstra, EWD1036 -- 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/