From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bryan Donlan Subject: Lockup with "BUG: using smp_processor_id() in preemptible" Date: Thu, 31 Dec 2009 11:21:35 -0500 Message-ID: <3e8340490912310821i625daf3bu6024f6644d2789a4@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: RT Return-path: Received: from mail-ew0-f219.google.com ([209.85.219.219]:56471 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbZLaQV4 (ORCPT ); Thu, 31 Dec 2009 11:21:56 -0500 Received: by ewy19 with SMTP id 19so4755640ewy.21 for ; Thu, 31 Dec 2009 08:21:55 -0800 (PST) Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi, With 2.6.31.6-rt19, I have an application which reliably triggers a system freeze on a dual-processor system. Prior to the lockup, there's this spam in logs: Dec 29 14:48:07 Ubuntu kernel: [ 346.332026] BUG: using smp_processor_id() in preemptible [00000000] code: SmartTool/4191 Dec 29 14:48:07 Ubuntu kernel: [ 346.332205] caller is __schedule+0x13/0xa70 Dec 29 14:48:07 Ubuntu kernel: [ 346.332210] Pid: 4191, comm: SmartTool Not tainted 2.6.31.6-rt19-ceng1 #1 Dec 29 14:48:07 Ubuntu kernel: [ 346.332214] Call Trace: Dec 29 14:48:07 Ubuntu kernel: [ 346.332224] [] debug_smp_processor_id+0xb9/0xd0 Dec 29 14:48:07 Ubuntu kernel: [ 346.332229] [] __schedule+0x13/0xa70 Dec 29 14:48:07 Ubuntu kernel: [ 346.332236] [] ? irq_exit+0x54/0x90 Dec 29 14:48:07 Ubuntu kernel: [ 346.332243] [] ? smp_apic_timer_interrupt+0x56/0x90 Dec 29 14:48:07 Ubuntu kernel: [ 346.332249] [] work_resched+0x5/0x19 Dec 29 14:48:07 Ubuntu kernel: [ 346.332256] BUG: using smp_processor_id() in preemptible [00000000] code: SmartTool/4191 Dec 29 14:48:07 Ubuntu kernel: [ 346.332425] caller is __schedule+0x6a/0xa70 Dec 29 14:48:07 Ubuntu kernel: [ 346.332429] Pid: 4191, comm: SmartTool Not tainted 2.6.31.6-rt19-ceng1 #1 Dec 29 14:48:07 Ubuntu kernel: [ 346.332432] Call Trace: Dec 29 14:48:07 Ubuntu kernel: [ 346.332437] [] debug_smp_processor_id+0xb9/0xd0 Dec 29 14:48:07 Ubuntu kernel: [ 346.332443] [] __schedule+0x6a/0xa70 Dec 29 14:48:07 Ubuntu kernel: [ 346.332449] [] ? irq_exit+0x54/0x90 Dec 29 14:48:07 Ubuntu kernel: [ 346.332454] [] ? smp_apic_timer_interrupt+0x56/0x90 Dec 29 14:48:07 Ubuntu kernel: [ 346.332460] [] work_resched+0x5/0x19 Dec 29 14:48:09 Ubuntu kernel: [ 349.658309] __ratelimit: 2 callbacks suppressed These two traces repeat constantly in the logs - I suppose the crash occurred when a migration eventually occurred in the middle of this. The processes running are polling several usb-serial devices. This does not occur with 2.6.29.6-rt24, or with SMP disabled (including after disabling a CPU at runtime). I'll try to get some ftrace results; in the meantime, any ideas? Kernel log, lspci, lsmod, and config at http://fushizen.net/~bd/rt-oops.tar.gz Thanks, Bryan Donlan