From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757448AbZHZOMV (ORCPT ); Wed, 26 Aug 2009 10:12:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756434AbZHZOMU (ORCPT ); Wed, 26 Aug 2009 10:12:20 -0400 Received: from mail-fx0-f217.google.com ([209.85.220.217]:54270 "EHLO mail-fx0-f217.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754558AbZHZOMT convert rfc822-to-8bit (ORCPT ); Wed, 26 Aug 2009 10:12:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=uKIEOl3ujLFlg+03IKgMKwkGCNrMO0+pxEXrXn7mH8vCzH8pp6aLCtE7shZUcq/Tkq 5bz387+DFeQ1xh0NxpVr2Su9I6kbSVpg5/1nVV8+u8Twek2SyCk35Pj8XGqsZ91RjL1N vZyu23xNyTYGeWTRC0baG06LZrOmgwpoT8i3o= MIME-Version: 1.0 In-Reply-To: <200908251459.37106.bjorn.helgaas@hp.com> References: <200908251251.37135.bjorn.helgaas@hp.com> <200908251459.37106.bjorn.helgaas@hp.com> Date: Wed, 26 Aug 2009 16:12:19 +0200 Message-ID: Subject: Re: INFO: possible circular locking dependency - kacpid acpi_os_wait_events_complete From: Zdenek Kabelac To: Bjorn Helgaas Cc: Linux Kernel Mailing List , len.brown@intel.com, linux-acpi@vger.kernel.org, Henrique de Moraes Holschuh , Zhang Rui , Paul Martin , Vojtech Gondzala Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/8/25 Bjorn Helgaas : > On Tuesday 25 August 2009 02:33:30 pm you wrote: >> 2009/8/25 Bjorn Helgaas : >> > On Tuesday 25 August 2009 02:10:58 am Zdenek Kabelac wrote: >> >> Now with 2.6.31-rc7 (3edf2fb9d80a46d6c32ba12547a42419845b4b76) >> >>  I'm getting this  INFO trace - also I've noticed complete reset during resume >> >> which could be eventually related to this >> > Do you have any evidence that points to thinkpad_acpi?  I looked >> > at the recent changes there, and I don't see anything obviously >> > related to kacpid or deferred work. >> > >> >> Well I've never seen this INFO trace before - also I'm not sure I >> could reliable retest it - might be coincidence of suspend out of port >> replicator and resume while being attached on it - however I do this >> relatively often and I start to see this after I' started to use -rc7 >> kernel. >> >> My guess is purely based on the fact that commit touching functions >> from INFO trace was recently merged to main tree. >> >> If there will be some time I could try to make few tests for suspend >> resume - but I hope the trace would be enough for analysis. > Well definitelly I do not have a reliable test case to deterministically trigger this INFO trace, but I think from the trace it looks like the acpi_os_wait_events_complete calls flush_workqueue which again calls acpi_os_execute_hp_deferred which again tries to invoke flush_workqueue - so is that correct ? (__acpi_os_execute looks somewhat cryptic in selection what would be called) This is the stack traceback cut from my first post: [] ? flush_workqueue+0x0/0xc0 [] ? acpi_os_execute_hp_deferred+0x0/0x43 [] flush_workqueue+0x5f/0xc0 [] ? flush_workqueue+0x0/0xc0 [] acpi_os_wait_events_complete+0x15/0x23 [] acpi_os_execute_hp_deferred+0x2f/0x43 [] worker_thread+0x1e4/0x3f0 So it looks like this issue is releated to commit: c02256be79a1a3557332ac51e653d574a2a7d2b5 Hopefully the author would be able to fix this ? Zdenek