From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760512AbYGOARX (ORCPT ); Mon, 14 Jul 2008 20:17:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932250AbYGOARH (ORCPT ); Mon, 14 Jul 2008 20:17:07 -0400 Received: from mga07.intel.com ([143.182.124.22]:3924 "EHLO azsmga101.ch.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932477AbYGOARG (ORCPT ); Mon, 14 Jul 2008 20:17:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.30,361,1212390000"; d="scan'208";a="20445826" Date: Mon, 14 Jul 2008 17:17:05 -0700 From: mark gross To: "Jakub W. Jozwicki" Cc: Andrew Morton , linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@timesys.com Subject: Re: [PATCH 2.6.25.10] pm_qos_params: change spinlock to rwlock Message-ID: <20080715001705.GB7079@linux.intel.com> Reply-To: mgross@linux.intel.com References: <200807130119.19663.jozwicki@aster.pl> <20080713012816.8c136efa.akpm@linux-foundation.org> <200807131505.25990.jozwicki@aster.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <200807131505.25990.jozwicki@aster.pl> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) X-OriginalArrivalTime: 15 Jul 2008 00:17:05.0045 (UTC) FILETIME=[1C673450:01C8E610] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 13, 2008 at 03:05:25PM +0200, Jakub W. Jozwicki wrote: > Sunday, 13 of July 2008 10:28:16 Andrew Morton napisał(a): > > On Sun, 13 Jul 2008 01:19:19 +0200 "Jakub W. Jozwicki" > wrote: > > > Concurrent calls to pm_qos_requirement shouldn't block each other. This > > > patch changes spinlock to rwlock and fixes issues with PREEMPT_RT. > > > > "fixes issues" is nowhere near an adequate description. > > > > Please provide complete descriptions for kernel patches. That includes > > describing the mysterious "issue" in full! > > > > Thanks. > > [ 114.647010] BUG: sleeping function called from invalid context swapper(0) > at kernel/rtmutex.c:742 > [ 114.647010] in_atomic():1 [00000001], irqs_disabled():0 > [ 114.647010] Pid: 0, comm: swapper Not tainted 2.6.25.10-rtXXX #10 > [ 114.647010] [] __might_sleep+0xf1/0xf8 > [ 114.647010] [] __rt_spin_lock+0x24/0x61 > [ 114.647010] [] rt_spin_lock+0x8/0xa > [ 114.647010] [] pm_qos_requirement+0x10/0x29 > [ 114.647010] [] menu_select+0x5d/0x7f > [ 114.647010] [] cpuidle_idle_call+0x47/0x9b > [ 114.647010] [] ? cpuidle_idle_call+0x0/0x9b > [ 114.647010] [] cpu_idle+0xaf/0x106 > [ 114.647010] [] rest_init+0x67/0x69 > [ 114.647010] ======================= > [ 115.649517] BUG: sleeping function called from invalid context swapper(0) > at kernel/rtmutex.c:742 > [ 115.649517] in_atomic():1 [00000001], irqs_disabled():0 > [ 115.649517] Pid: 0, comm: swapper Not tainted 2.6.25.10-rtXXX #10 > [ 115.649517] [] __might_sleep+0xf1/0xf8 > [ 115.649517] [] __rt_spin_lock+0x24/0x61 > [ 115.649517] [] rt_spin_lock+0x8/0xa > [ 115.649517] [] pm_qos_requirement+0x10/0x29 > [ 115.649517] [] menu_select+0x5d/0x7f > [ 115.649517] [] cpuidle_idle_call+0x47/0x9b > [ 115.649517] [] ? cpuidle_idle_call+0x0/0x9b > [ 115.649517] [] cpu_idle+0xaf/0x106 > [ 115.649517] [] rest_init+0x67/0x69 > [ 115.649517] ======================= > [ 116.650040] BUG: sleeping function called from invalid context swapper(0) > at kernel/rtmutex.c:742 > [ 116.650040] in_atomic():1 [00000001], irqs_disabled():0 > [ 116.650040] Pid: 0, comm: swapper Not tainted 2.6.25.10-rtXXX #10 > [ 116.650040] [] __might_sleep+0xf1/0xf8 > [ 116.650040] [] __rt_spin_lock+0x24/0x61 > [ 116.650040] [] rt_spin_lock+0x8/0xa > [ 116.650040] [] pm_qos_requirement+0x10/0x29 > [ 116.650040] [] menu_select+0x5d/0x7f > [ 116.650040] [] cpuidle_idle_call+0x47/0x9b > [ 116.650040] [] ? cpuidle_idle_call+0x0/0x9b > [ 116.650040] [] cpu_idle+0xaf/0x106 > [ 116.650040] [] rest_init+0x67/0x69 > [ 116.650040] ======================= Ah, this a PREEMPT_RT only issue. Let me study up on rwlocks a bit and get back to you on this. --mgross