diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2013-06-14 17:16:35 +0200 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-06-24 21:13:01 +0200 |
| commit | 24f0d259f259ba3ce8aa4583de3a4d0a8485b989 (patch) | |
| tree | 7782f90c4c0055dc3e8d4b8f1cc830fd59f7a851 | |
| parent | 5620ea4bb6966c66944c0122497d90bca75c3e27 (diff) | |
kernel/hotplug: restore original cpu mask oncpu/down
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>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/cpu.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index c3ce0b9dc8fe..4a4160fcb44f 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -642,6 +642,7 @@ 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; @@ -652,6 +653,12 @@ 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); @@ -660,7 +667,8 @@ 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(); @@ -738,6 +746,9 @@ 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; } |