Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754001AbYFPKed (ORCPT ); Mon, 16 Jun 2008 06:34:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751875AbYFPKeZ (ORCPT ); Mon, 16 Jun 2008 06:34:25 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:41129 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751732AbYFPKeZ (ORCPT ); Mon, 16 Jun 2008 06:34:25 -0400 Subject: Re: [BUG: NULL pointer dereference] cgroups and RT scheduling interact badly. From: Peter Zijlstra To: "Daniel K." Cc: mingo@elte.hu, menage@google.com, Linux Kernel Mailing List In-Reply-To: <485445AE.2010602@uw.no> References: <485445AE.2010602@uw.no> Content-Type: text/plain Date: Mon, 16 Jun 2008 12:34:07 +0200 Message-Id: <1213612447.16944.99.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1376 Lines: 52 On Sun, 2008-06-15 at 00:26 +0200, Daniel K. wrote: > I get the following on the latest Linus git tree. > > Testcase: > > mkdir /dev/cgroup > mount -t cgroup -o cpu,cpuset cgroup /dev/cgroup > > mkdir -p /dev/cgroup/burn/oops > cd /dev/cgroup/burn > > echo 3 > cpuset.cpus > echo 0 > cpuset.mems > echo 1000000 > cpu.rt_period_us > echo 940000 > cpu.rt_runtime_us > > echo 3 > oops/cpuset.cpus > echo 0 > oops/cpuset.mems > echo 100000 > oops/cpu.rt_period_us > echo 4000 > oops/cpu.rt_runtime_us > > echo $$ > oops/tasks > schedtool -R -p 1 -e burnP6 > > And then it breaks into the pieces below, as captured by netconsole. Excellent report, thanks! Does the below work for you? Signed-off-by: Peter Zijlstra --- Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -7784,7 +7784,6 @@ static void init_tg_rt_entry(struct task else rt_se->rt_rq = parent->my_q; - rt_se->rt_rq = &rq->rt; rt_se->my_q = rt_rq; rt_se->parent = parent; INIT_LIST_HEAD(&rt_se->run_list); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/