From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756557AbZAYCj2 (ORCPT ); Sat, 24 Jan 2009 21:39:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754368AbZAYCjU (ORCPT ); Sat, 24 Jan 2009 21:39:20 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:38892 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753971AbZAYCjT (ORCPT ); Sat, 24 Jan 2009 21:39:19 -0500 Date: Sat, 24 Jan 2009 18:37:46 -0800 From: Andrew Morton To: "Maciej Rutecki" Cc: "Linus Torvalds" , "Rafael J. Wysocki" , "Linux Kernel Mailing List" , Ingo Molnar , Thomas Gleixner , Rusty Russell Subject: Re: [Linux 2.6.29-rc2] BUG: using smp_processor_id() in preemptible Message-Id: <20090124183746.395f597b.akpm@linux-foundation.org> In-Reply-To: <8db1092f0901170058k325dc6ddtddb42deea1ddd098@mail.gmail.com> References: <8db1092f0901170058k325dc6ddtddb42deea1ddd098@mail.gmail.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 17 Jan 2009 09:58:47 +0100 "Maciej Rutecki" wrote: > During suspend to ram: > [ 131.287012] BUG: using smp_processor_id() in preemptible [00000000] > code: suspend_to_ram./2958 > [ 131.287012] caller is retrigger_next_event+0x13/0xb0 > [ 131.287012] Pid: 2958, comm: suspend_to_ram. Not tainted 2.6.29-rc2 #1 > [ 131.287012] Call Trace: > [ 131.287012] [] debug_smp_processor_id+0xbf/0xd0 > [ 131.287012] [] retrigger_next_event+0x13/0xb0 > [ 131.287012] [] raw_notifier_call_chain+0x17/0x20 > [ 131.287012] [] timekeeping_resume+0xe8/0x110 > [ 131.287012] [] __sysdev_resume+0x11/0x50 > [ 131.287012] [] sysdev_resume+0x47/0x80 > [ 131.287012] [] device_power_up+0x8/0x10 > [ 131.287012] [] suspend_devices_and_enter+0xeb/0x160 > [ 131.287012] [] freeze_processes+0x4f/0xa0 > [ 131.287012] [] enter_state+0xfd/0x150 > [ 131.287012] [] state_store+0x8c/0xd0 > [ 131.287012] [] state_store+0x0/0xd0 > [ 131.287012] [] kobj_attr_store+0x24/0x30 > [ 131.287012] [] sysfs_write_file+0xa1/0x110 > [ 131.287012] [] sysfs_write_file+0x0/0x110 > [ 131.287012] [] vfs_write+0xa8/0x140 > [ 131.287012] [] sys_write+0x41/0x80 > [ 131.287012] [] sysenter_do_call+0x12/0x21 > [ 131.287012] [] init_cyrix+0x72/0x444 > [ 131.287012] BUG: using smp_processor_id() in preemptible [00000000] > code: suspend_to_ram./2958 Coming out of the hrtimer_hres_active() call, I assume. Is this new behaviour, or were 2.6.28 and earlier doing it? If it's new behaviour then I'm not sure why, but it triggers my Rusty nerve. afaict we should a) remove the wrong "Called with interrupts disabled via on_each_cpu()" comment from retrigger_next_event(), and replace it with something useful and truthful. b) change hres_timers_resume() to do local_irq_save/restore Does this fix it? --- a/kernel/hrtimer.c~a +++ a/kernel/hrtimer.c @@ -562,7 +562,7 @@ static int hrtimer_reprogram(struct hrti /* * Retrigger next event is called after clock was set * - * Called with interrupts disabled via on_each_cpu() + * Called with interrupts disabled. */ static void retrigger_next_event(void *arg) { @@ -614,8 +614,12 @@ void clock_was_set(void) */ void hres_timers_resume(void) { + unsigned long flags; + /* Retrigger the CPU local events: */ + local_irq_save(flags); retrigger_next_event(NULL); + local_irq_restore(flags); } /* _