From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751674Ab1HYD5v (ORCPT ); Wed, 24 Aug 2011 23:57:51 -0400 Received: from oproxy4-pub.bluehost.com ([69.89.21.11]:58931 "HELO oproxy4-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750795Ab1HYD5r (ORCPT ); Wed, 24 Aug 2011 23:57:47 -0400 Date: Wed, 24 Aug 2011 20:57:45 -0700 From: Randy Dunlap To: Frederic Weisbecker Cc: LKML , Len Brown , "Paul E. McKenney" , Peter Zijlstra , Ingo Molnar Subject: Re: Bug: ACPI, scheduling while atomic (was Re: [PATCH 0/4] sched: Make sleep inside atomic detection work on !PREEMPT) Message-Id: <20110824205745.cd3f5f6c.rdunlap@xenotime.net> In-Reply-To: <20110608224939.GC25771@somewhere.redhat.com> References: <1307555315-30989-1-git-send-email-fweisbec@gmail.com> <20110608224939.GC25771@somewhere.redhat.com> Organization: YPO4 X-Mailer: Sylpheed 2.7.1 (GTK+ 2.16.6; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {1807:box742.bluehost.com:xenotime:xenotime.net} {sentby:smtp auth 50.53.38.135 authed with rdunlap@xenotime.net} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Jun 2011 00:49:41 +0200 Frederic Weisbecker wrote: > On Wed, Jun 08, 2011 at 07:48:31PM +0200, Frederic Weisbecker wrote: > > Aside it may mostly avoid the need for a specific PROVE_RCU > > check when we sleep inside an rcu read side critical section. > > > > Better make sleeping inside atomic sections work everywhere. > > BTW, it has led to detect a bug in the ACPI code. It happens in > !CONFIG_PREEMPT: > > [ 0.160187] BUG: scheduling while atomic: swapper/0/0x10000002 > [ 0.166016] no locks held by swapper/0. > [ 0.170014] Modules linked in: > [ 0.173107] Pid: 0, comm: swapper Not tainted 2.6.39+ #124 > [ 0.180014] Call Trace: > [ 0.182481] [] __schedule_bug+0x85/0x90 > [ 0.187967] [] schedule+0x75c/0xa40 > [ 0.190022] [] ? trace_hardirqs_on+0xd/0x10 > [ 0.200023] [] ? acpi_ps_free_op+0x22/0x24 > [ 0.205776] [] __cond_resched+0x25/0x40 > [ 0.210022] [] _cond_resched+0x2b/0x40 > [ 0.215420] [] acpi_ps_complete_op+0x262/0x278 > [ 0.220023] [] acpi_ps_parse_loop+0x80b/0x960 > [ 0.230023] [] acpi_ps_parse_aml+0x98/0x274 > [ 0.235859] [] acpi_ns_one_complete_parse+0x103/0x120 > [ 0.240021] [] ? up+0x2a/0x50 > [ 0.244641] [] acpi_ns_parse_table+0x1b/0x34 > [ 0.250022] [] acpi_ns_load_table+0x4a/0x8c > [ 0.260023] [] acpi_load_tables+0x9c/0x15d > [ 0.265774] [] acpi_early_init+0x6c/0xf7 > [ 0.270022] [] start_kernel+0x400/0x415 > [ 0.275508] [] x86_64_start_reservations+0x131/0x135 > [ 0.280022] [] x86_64_start_kernel+0x103/0x112 > > ACPI_PREEMPTION_POINT() is called from acpi_ps_complete_op() and schedules > if !PREEMPT. But preemption is disabled as we are in early bootup. This still happens in 3.1-rc[123]. Was there a patch for it? --- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code ***