From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762585AbYFZNj4 (ORCPT ); Thu, 26 Jun 2008 09:39:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752703AbYFZNjp (ORCPT ); Thu, 26 Jun 2008 09:39:45 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39148 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbYFZNjo (ORCPT ); Thu, 26 Jun 2008 09:39:44 -0400 Date: Thu, 26 Jun 2008 15:39:24 +0200 From: Ingo Molnar To: Dario Faggioli Cc: Michael Trimarchi , PeterZijlstra , "Daniel K." , Linux Kernel Mailing List Subject: Re: divide error trying to set rt_period to zero Message-ID: <20080626133924.GA20188@elte.hu> References: <1214432249.5464.22.camel@Palanthas.Krynn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1214432249.5464.22.camel@Palanthas.Krynn> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Dario Faggioli wrote: > Hi all again, > > Here it is another little Oops we found: > > echo 0 > /dev/cgroups/0/cpu.rt_period_us > or > echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us > > [ 205.509825] divide error: 0000 [#1] > [ 205.510151] Modules linked in: > [ 205.510151] > [ 205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33) > [ 205.510151] EIP: 0060:[] EFLAGS: 00000293 CPU: 0 > [ 205.510151] EIP is at div64_u64+0x5f/0x70 > [ 205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000 > [ 205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50 > [ 205.510151] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 > [ 205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000) > [ 205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000 > [ 205.510151] c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0 > [ 205.510151] c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea > [ 205.510151] Call Trace: > [ 205.510151] [] ? __rt_schedulable+0x1cd/0x240 > [ 205.510151] [] ? cgroup_file_open+0x18/0xe0 > [ 205.510151] [] ? tg_set_bandwidth+0xa4/0xf0 > [ 205.510151] [] ? sched_group_set_rt_period+0x36/0x50 > [ 205.510151] [] ? cpu_rt_period_write_uint+0xe/0x10 > [ 205.510151] [] ? cgroup_file_write+0x125/0x160 > [ 205.510151] [] ? hrtimer_interrupt+0x155/0x190 > [ 205.510151] [] ? security_file_permission+0xf/0x20 > [ 205.510151] [] ? rw_verify_area+0x48/0xc0 > [ 205.510151] [] ? dupfd+0x104/0x130 > [ 205.510151] [] ? vfs_write+0x9c/0x160 > [ 205.510151] [] ? cgroup_file_write+0x0/0x160 > [ 205.510151] [] ? sys_write+0x3d/0x70 > [ 205.510151] [] ? sysenter_past_esp+0x6a/0x91 > [ 205.510151] ======================= > [ 205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56 > [ 205.510151] EIP: [] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50 > > The attached patch solves the issue for me. > @@ -8501,6 +8501,9 @@ int sched_group_set_rt_period(struct task_group > *tg, long rt_period_us) > rt_period = (u64)rt_period_us * NSEC_PER_USEC; > rt_runtime = tg->rt_bandwidth.rt_runtime; > > + if (period == 0) > + return -EINVAL; this patch doesnt even build, because there's no "period" variable. Ingo