From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org,
linux-rt-users <linux-rt-users@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Carsten Emde <C.Emde@osadl.org>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
John Kacur <jkacur@redhat.com>, <stable-rt@vger.kernel.org>
Subject: [PATCH RT 08/16] kernel/hotplug: restore original cpu mask oncpu/down
Date: Mon, 09 Sep 2013 10:35:25 -0400 [thread overview]
Message-ID: <20130909143535.432817617@goodmis.org> (raw)
In-Reply-To: 20130909143517.641735717@goodmis.org
[-- Attachment #1: 0008-kernel-hotplug-restore-original-cpu-mask-oncpu-down.patch --]
[-- Type: text/plain, Size: 1818 bytes --]
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
If a task which is allowed to run only on CPU X puts CPU Y down then it
will be allowed on all CPUs but the on CPU Y after it comes back from
kernel. This patch ensures that we don't lose the initial setting unless
the CPU the task is running is going down.
Cc: stable-rt@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
kernel/cpu.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 25853dc..4abfd5d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -497,6 +497,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
.hcpu = hcpu,
};
cpumask_var_t cpumask;
+ cpumask_var_t cpumask_org;
if (num_online_cpus() == 1)
return -EBUSY;
@@ -507,6 +508,12 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
/* Move the downtaker off the unplug cpu */
if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
return -ENOMEM;
+ if (!alloc_cpumask_var(&cpumask_org, GFP_KERNEL)) {
+ free_cpumask_var(cpumask);
+ return -ENOMEM;
+ }
+
+ cpumask_copy(cpumask_org, tsk_cpus_allowed(current));
cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
set_cpus_allowed_ptr(current, cpumask);
free_cpumask_var(cpumask);
@@ -515,7 +522,8 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
if (mycpu == cpu) {
printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
migrate_enable();
- return -EBUSY;
+ err = -EBUSY;
+ goto restore_cpus;
}
cpu_hotplug_begin();
@@ -573,6 +581,9 @@ out_cancel:
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
+restore_cpus:
+ set_cpus_allowed_ptr(current, cpumask_org);
+ free_cpumask_var(cpumask_org);
return err;
}
--
1.7.10.4
next prev parent reply other threads:[~2013-09-09 14:35 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-09 14:35 [PATCH RT 00/16] 3.0.89-rt118-rc1 stable review Steven Rostedt
2013-09-09 14:35 ` Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 01/16] sched/workqueue: Only wake up idle workers if not blocked on sleeping spin lock Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 02/16] x86/mce: fix mce timer interval Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 03/16] genirq: Set irq thread to RT priority on creation Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 04/16] list_bl.h: make list head locking RT safe Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 05/16] list_bl.h: fix it for for !SMP && !DEBUG_SPINLOCK Steven Rostedt
2013-09-09 14:35 ` Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 06/16] timers: prepare for full preemption improve Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 07/16] kernel/cpu: fix cpu down problem if kthreads cpu is going down Steven Rostedt
2013-09-09 14:35 ` Steven Rostedt [this message]
2013-09-09 14:35 ` [PATCH RT 09/16] drm/i915: drop trace_i915_gem_ring_dispatch on rt Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 10/16] rt,ntp: Move call to schedule_delayed_work() to helper thread Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 11/16] hwlat-detector: Update hwlat_detector to add outer loop detection Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 12/16] hwlat-detect/trace: Export trace_clock_local for hwlat-detector Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 13/16] hwlat-detector: Use trace_clock_local if available Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 14/16] hwlat-detector: Use thread instead of stop machine Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 15/16] genirq: do not invoke the affinity callback via a workqueue Steven Rostedt
2013-09-09 14:35 ` [PATCH RT 16/16] Linux 3.0.89-rt118-rc1 Steven Rostedt
-- strict thread matches above, loose matches on Subject: below --
2013-09-09 12:47 [PATCH RT 00/16] 3.2.50-rt71-rc1 stable review Steven Rostedt
2013-09-09 12:47 ` [PATCH RT 08/16] kernel/hotplug: restore original cpu mask oncpu/down Steven Rostedt
2013-09-09 12:45 [PATCH RT 00/16] 3.4.57-rt73-rc1 stable review Steven Rostedt
2013-09-09 12:45 ` [PATCH RT 08/16] kernel/hotplug: restore original cpu mask oncpu/down Steven Rostedt
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