From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760022AbZA3Boz (ORCPT ); Thu, 29 Jan 2009 20:44:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752335AbZA3Bor (ORCPT ); Thu, 29 Jan 2009 20:44:47 -0500 Received: from gw.goop.org ([64.81.55.164]:39341 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbZA3Boq (ORCPT ); Thu, 29 Jan 2009 20:44:46 -0500 Message-ID: <49825B8B.2000202@goop.org> Date: Thu, 29 Jan 2009 17:44:43 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: paulmck@linux.vnet.ibm.com CC: Ingo Molnar , Linux Kernel Mailing List Subject: Re: Seeing "huh, entered softirq 8 ffffffff802682aa preempt_count 00000100, exited with 00010100?" in tip.git References: <498229CF.1090007@goop.org> <20090130005953.GD6716@linux.vnet.ibm.com> In-Reply-To: <20090130005953.GD6716@linux.vnet.ibm.com> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paul E. McKenney wrote: > On Thu, Jan 29, 2009 at 02:12:31PM -0800, Jeremy Fitzhardinge wrote: > >> When I boot my x86-64 tip.git kernel under Xen, I'm seeing: >> >> pnp: PnP ACPI: disabled >> NET: Registered protocol family 2 >> huh, entered softirq 8 ffffffff802682aa preempt_count 00000100, exited with >> 00010100? >> IP route cache hash table entries: 512 (order: 0, 4096 bytes) >> TCP established hash table entries: 1024 (order: 2, 16384 bytes) >> [...] >> XENBUS: Device with no driver: device/console/0 >> Freeing unused kernel memory: 372k freed >> Red Hat nash version 6.0.19 starting >> Mounting proc filesystem >> Mounting sysfs filesystem >> Creating /dev >> BUG: scheduling while atomic: swapper/0/0x00010000 >> Modules linked in: >> Pid: 0, comm: swapper Not tainted 2.6.29-rc3-tip #481 >> Call Trace: >> [] __schedule_bug+0x62/0x66 >> [] ? retint_restore_args+0x5/0x20 >> [] __schedule+0x95/0x792 >> [] ? _stext+0x3aa/0x1000 >> [] ? _stext+0x3aa/0x1000 >> [] schedule+0xe/0x22 >> [] cpu_idle+0x70/0x72 >> [] cpu_bringup_and_idle+0x13/0x15 >> Creating initial device nodes >> Setting up hotplug. >> >> >> From what I can see, softirq 8 is the RCU softirq. I don't know if the >> "scheduling while atomic" is related or not, but its two new schedulerish >> symptoms appearing at once, so I think its likely they're related. >> > > Hmmm... Mysterious, as you seem to be using classic RCU, which hasn't > changed in awhile. Which branch of the tip tree are you using? > tip/master. It looks like this appeared since -rc1. Mu current suspicion is the percpu changes, since I'm seeing some other strange symptoms. J