Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757255AbYHUR7W (ORCPT ); Thu, 21 Aug 2008 13:59:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752127AbYHUR7M (ORCPT ); Thu, 21 Aug 2008 13:59:12 -0400 Received: from mail-gx0-f16.google.com ([209.85.217.16]:33784 "EHLO mail-gx0-f16.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750861AbYHUR7L (ORCPT ); Thu, 21 Aug 2008 13:59:11 -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=oNerCkmvMWsN+przu5SwA7nfciRun2yukV29M88WWh8DTB/idAKusNJJYXP2vnCB3c MWU7vVlADxxxrV4KYyJ3VPuEqHdqo/zmmW3K6J5GsvZmVctAuUpaUY86HhOWeReQCR7F hR/b75zBNzUkEHZ60PEkOp1jjvOXm/naGp1fM= Message-ID: <19f34abd0808211059m451f5f7au949217aeecccccaf@mail.gmail.com> Date: Thu, 21 Aug 2008 19:59:10 +0200 From: "Vegard Nossum" To: "Dmitry Adamushko" Subject: Re: latest -git: hibernate: possible circular locking dependency detected Cc: "Oleg Nesterov" , "Peter Zijlstra" , "Rafael J. Wysocki" , "Max Krasnyanskiy" , "Linux Kernel Mailing List" In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <19f34abd0808210804y7ee91d1fy12da5ad6f82d2451@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2468 Lines: 72 On Thu, Aug 21, 2008 at 7:38 PM, Dmitry Adamushko wrote: >> [ INFO: possible circular locking dependency detected ] >> 2.6.27-rc4-00003-ga798564 #28 [...] > this path is triggered as a result of "echo disk > /sys/power/state" Yes. That is what I typed. > > disable_nonboot_cpus() calls cpu_maps_update_being() which takes > "cpu_add_remove_lock" (lock-1). > > If we go down the road cleanup_workqueue_thread() -> > flush_cpu_workqueue() will take "cwq->lock" (lock-2). > So this should be the second lock. > > [...] > hmm, did you somehow hit "Sysrq + o"? > > 'cause I don't see any other places (say, with handle_sysrq(k,...) > where "k" migth be 'o') from where do_power_off() might have been > triggered... > No. But in my logs I often saw SysRq triggered, even though I didn't do it any of these times: log-20080821-104053.txt:SysRq : SysRq : Show State log-20080821-105541.txt:SysRq : Emergency Sync log-20080821-105541.txt:SysRq : Emergency Sync log-20080821-105541.txt:SysRq : Power Off log-20080821-110514.txt:SysRq : Terminate All Tasks log-20080821-111650.txt:SysRq : HELP : loglevel0-8 <6>serial 00:0d: activated log-20080821-111650.txt:SysRq : Power Off log-20080821-111650.txt:SysRq : Terminate All Tasks log-20080821-111650.txt:SysRq : SysRq : <6>serial 00:0d: activated log-20080821-120628.txt:SysRq : SysRq : HELP : HELP : <6>serial 00:0d: activated log-20080821-120628.txt:SysRq : SysRq : HELP : HELP : <6>serial 00:0d: activated (And it seems to pick a random letter too. It even showed the "HELP:" line at one point!) I have no idea why this happens. Is it possible to trigger SysRq by writing data on the other end of the serial console? (Maybe my cable is bad or something, but data seems to be going in both directions over my serial console.) The rest I will not comment on. It also seems unlikely that I will be able to test any patches reliably, simply because I see a few different kinds of issues on resume :-( Thanks! 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/