From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: [patch] sched, rt: fix migrate_enable() thinko Date: Tue, 23 Aug 2011 16:12:43 +0200 Message-ID: <1314108763.6689.4.camel@marge.simson.net> References: <1313232790.25267.7.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-kernel , Thomas Gleixner , "Paul E. McKenney" , linux-rt-users To: Peter Zijlstra Return-path: Received: from mailout-de.gmx.net ([213.165.64.23]:51318 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753460Ab1HWOMw (ORCPT ); Tue, 23 Aug 2011 10:12:52 -0400 In-Reply-To: <1313232790.25267.7.camel@twins> Sender: linux-rt-users-owner@vger.kernel.org List-ID: Assigning mask = tsk_cpus_allowed(p) after p->migrate_disable = 0 ensures that we won't see a mask change.. no push/pull, we stack tasks on one CPU. Also add a couple fields to sched_debug for the next guy. Signed-off-by: Mike Galbraith --- kernel/sched.c | 4 +++- kernel/sched_debug.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) Index: linux-2.6/kernel/sched.c =================================================================== --- linux-2.6.orig/kernel/sched.c +++ linux-2.6/kernel/sched.c @@ -6375,12 +6375,14 @@ void migrate_enable(void) */ rq = this_rq(); raw_spin_lock_irqsave(&rq->lock, flags); - p->migrate_disable = 0; mask = tsk_cpus_allowed(p); + p->migrate_disable = 0; WARN_ON(!cpumask_test_cpu(smp_processor_id(), mask)); if (!cpumask_equal(&p->cpus_allowed, mask)) { + /* Get the mask now that migration is enabled */ + mask = tsk_cpus_allowed(p); if (p->sched_class->set_cpus_allowed) p->sched_class->set_cpus_allowed(p, mask); p->rt.nr_cpus_allowed = cpumask_weight(mask); Index: linux-2.6/kernel/sched_debug.c =================================================================== --- linux-2.6.orig/kernel/sched_debug.c +++ linux-2.6/kernel/sched_debug.c @@ -235,6 +235,7 @@ void print_rt_rq(struct seq_file *m, int P(rt_throttled); PN(rt_time); PN(rt_runtime); + P(rt_nr_migratory); #undef PN #undef P @@ -484,6 +485,8 @@ void proc_sched_show_task(struct task_st P(se.load.weight); P(policy); P(prio); + P(migrate_disable); + P(rt.nr_cpus_allowed); #undef PN #undef __PN #undef P