From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Goebel Subject: Re: [RT] oops in 4.1.3-rt3 Date: Mon, 17 Aug 2015 03:33:43 +0000 (UTC) Message-ID: References: <20150803142700.1de720e4@sluggy> <20150804080829.GB9956@opentech.at> <20150816115859.GD7004@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: linux-rt-users@vger.kernel.org Return-path: Received: from plane.gmane.org ([80.91.229.3]:60930 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751034AbbHQDfH (ORCPT ); Sun, 16 Aug 2015 23:35:07 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1ZRBCR-0004xN-KT for linux-rt-users@vger.kernel.org; Mon, 17 Aug 2015 05:35:04 +0200 Received: from S0106602ad0951f35.vc.shawcable.net ([24.84.40.136]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Aug 2015 05:35:03 +0200 Received: from alex.goebel by S0106602ad0951f35.vc.shawcable.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 17 Aug 2015 05:35:03 +0200 Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi, Sebastian Andrzej Siewior linutronix.de> writes: > This might be a .config thing, device driver or user land behaviour. > Usually ksoftirqd should remain (almost) idle because most of BH work > remains in task-context and not in ksoftirqd. tasklets for instance > should run in ksoftirqd. So a function trace or event tracing to figure > out what is scheduling the softirq might give a pointer. I have a problem that might be related, or at least I suffer from the same symptoms: Trying to run various Debian 4.1 (and 4.0 as well, IIRC) -rt kernels on a Core i7-720QM Thinkpad, it boots up, I can log in, everything seems normal, but then after a few minutes, not doing anything special, things get sluggish and within seconds everything grinds to a complete halt. In the last screen update I had, there was no double-digit percentage of ksoftirqd though. Below is what I get in the logs. Note that it doesn't actually shut down, it just freezes and a hard reset is needed. The same kernels as non-RT work fine. Not sure if this is really related, but perhaps it helps. Cheers, Alex Aug 10 17:04:52 linux kernel: [ 189.542192] INFO: rcu_preempt detected stalls on CPUs/tasks: { 3} (detected by 0, t=5252 jiffies, g=3874, c=3873, q=8201) Aug 10 17:04:52 linux kernel: [ 189.542194] Task dump for CPU 3: Aug 10 17:04:52 linux kernel: [ 189.542200] swapper/3 R running task 0 0 1 0x00200000 Aug 10 17:04:52 linux kernel: [ 189.542206] ffffffff8136e2fa ffffffff8101f9e5 ffff8803333eee00 0000000008004000 Aug 10 17:04:52 linux kernel: [ 189.542209] 0000000000000004 0000000000000004 ffffffff8145baf4 0000000000000000 Aug 10 17:04:52 linux kernel: [ 189.542212] 0000000000000000 ffff88033338f020 ffff8803333eee00 ffffffff8190b640 Aug 10 17:04:52 linux kernel: [ 189.542213] Call Trace: Aug 10 17:04:52 linux kernel: [ 189.542224] [] ? intel_idle+0x12a/0x140 Aug 10 17:04:52 linux kernel: [ 189.542230] [] ? read_tsc+0x5/0x10 Aug 10 17:04:52 linux kernel: [ 189.542238] [] ? cpuidle_enter_state+0x74/0x270 Aug 10 17:04:52 linux kernel: [ 189.542244] [] ? cpu_startup_entry+0x3a8/0x4e0 Aug 10 17:04:52 linux kernel: [ 189.542249] [] ? start_secondary+0x169/0x190 Aug 10 17:04:52 linux kernel: [ 189.542254] rcu_preempt kthread starved for 5251 jiffies! Aug 10 17:05:01 linux CRON[4531]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1) Aug 10 17:05:33 linux kernel: [ 210.562994] INFO: rcu_preempt detected stalls on CPUs/tasks: { 3} (detected by 1, t=5252 jiffies, g=3875, c=3874, q=14365) Aug 10 17:05:33 linux kernel: [ 210.562997] Task dump for CPU 3: Aug 10 17:05:33 linux kernel: [ 210.563003] swapper/3 R running task 0 0 1 0x00200000 Aug 10 17:05:33 linux kernel: [ 210.563081] ffffffff8136e2fa ffffffff8101f9e5 ffff8803333eee00 0000000008004000 Aug 10 17:05:33 linux kernel: [ 210.563085] 0000000000000004 0000000000000004 ffffffff8145baf4 0000000000000000 Aug 10 17:05:33 linux kernel: [ 210.563090] 0000000000000000 ffff88033338f020 ffff8803333eee00 ffffffff8190b640 Aug 10 17:05:33 linux kernel: [ 210.563091] Call Trace: Aug 10 17:05:33 linux kernel: [ 210.563103] [] ? intel_idle+0x12a/0x140 Aug 10 17:05:33 linux kernel: [ 210.563111] [] ? read_tsc+0x5/0x10 Aug 10 17:05:33 linux kernel: [ 210.563121] [] ? cpuidle_enter_state+0x74/0x270 Aug 10 17:05:33 linux kernel: [ 210.563133] [] ? cpu_startup_entry+0x3a8/0x4e0 Aug 10 17:05:33 linux kernel: [ 210.563139] [] ? start_secondary+0x169/0x190 Aug 10 17:05:33 linux kernel: [ 210.563143] rcu_preempt kthread starved for 5252 jiffies! Aug 10 17:05:34 linux shutdown[4689]: shutting down for system halt Aug 10 17:05:34 linux init: Switching to runlevel: 0 Aug 10 17:05:34 linux shutdown[4822]: shutting down for system halt