diff options
| -rw-r--r-- | include/linux/stop_machine.h | 1 | ||||
| -rw-r--r-- | kernel/cpu.c | 2 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 23 |
3 files changed, 15 insertions, 11 deletions
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 414d924318ce..7b76362b381c 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -33,6 +33,7 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf); int stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg); +void stop_machine_park(int cpu); #else /* CONFIG_SMP */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 050c63472f03..c85df2775b73 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -344,7 +344,7 @@ static int take_cpu_down(void *_param) /* Give up timekeeping duties */ tick_handover_do_timer(); /* Park the stopper thread */ - kthread_park(current); + stop_machine_park((long)param->hcpu); return 0; } diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 12484e5d5c88..6a402098d4ab 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -452,6 +452,18 @@ repeat: } } +void stop_machine_park(int cpu) +{ + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + /* + * Lockless. cpu_stopper_thread() will take stopper->lock and flush + * the pending works before it parks, until then it is fine to queue + * the new works. + */ + stopper->enabled = false; + kthread_park(stopper->thread); +} + extern void sched_set_stop_task(int cpu, struct task_struct *stop); static void cpu_stop_create(unsigned int cpu) @@ -462,17 +474,8 @@ static void cpu_stop_create(unsigned int cpu) static void cpu_stop_park(unsigned int cpu) { struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); - struct cpu_stop_work *work, *tmp; - unsigned long flags; - /* drain remaining works */ - spin_lock_irqsave(&stopper->lock, flags); - list_for_each_entry_safe(work, tmp, &stopper->works, list) { - list_del_init(&work->list); - cpu_stop_signal_done(work->done, false); - } - stopper->enabled = false; - spin_unlock_irqrestore(&stopper->lock, flags); + WARN_ON(!list_empty(&stopper->works)); } static void cpu_stop_unpark(unsigned int cpu) |