diff options
Diffstat (limited to 'kernel/stop_machine.c')
| -rw-r--r-- | kernel/stop_machine.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 2f194e965715..aaac68c5c3be 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -37,10 +37,10 @@ struct cpu_stopper { spinlock_t lock; bool enabled; /* is this stopper enabled? */ struct list_head works; /* list of pending works */ - struct task_struct *thread; /* stopper thread */ }; static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper); +static DEFINE_PER_CPU(struct task_struct *, cpu_stopper_task); static bool stop_machine_initialized = false; static void cpu_stop_init_done(struct cpu_stop_done *done, unsigned int nr_todo) @@ -62,16 +62,18 @@ static void cpu_stop_signal_done(struct cpu_stop_done *done, bool executed) } /* queue @work to @stopper. if offline, @work is completed immediately */ -static void cpu_stop_queue_work(struct cpu_stopper *stopper, - struct cpu_stop_work *work) +static void cpu_stop_queue_work(unsigned int cpu, struct cpu_stop_work *work) { + struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); + struct task_struct *p = per_cpu(cpu_stopper_task, cpu); + unsigned long flags; spin_lock_irqsave(&stopper->lock, flags); if (stopper->enabled) { list_add_tail(&work->list, &stopper->works); - wake_up_process(stopper->thread); + wake_up_process(p); } else cpu_stop_signal_done(work->done, false); @@ -108,7 +110,7 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done }; cpu_stop_init_done(&done, 1); - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), &work); + cpu_stop_queue_work(cpu, &work); wait_for_completion(&done.completion); return done.executed ? done.ret : -ENOENT; } @@ -130,7 +132,7 @@ void stop_one_cpu_nowait(unsigned int cpu, cpu_stop_fn_t fn, void *arg, struct cpu_stop_work *work_buf) { *work_buf = (struct cpu_stop_work){ .fn = fn, .arg = arg, }; - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), work_buf); + cpu_stop_queue_work(cpu, work_buf); } /* static data for stop_cpus */ @@ -159,8 +161,7 @@ static void queue_stop_cpus_work(const struct cpumask *cpumask, */ preempt_disable(); for_each_cpu(cpu, cpumask) - cpu_stop_queue_work(&per_cpu(cpu_stopper, cpu), - &per_cpu(stop_cpus_work, cpu)); + cpu_stop_queue_work(cpu, &per_cpu(stop_cpus_work, cpu)); preempt_enable(); } @@ -304,12 +305,11 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, { unsigned int cpu = (unsigned long)hcpu; struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu); - struct task_struct *p; + struct task_struct *p = per_cpu(cpu_stopper_task, cpu); switch (action & ~CPU_TASKS_FROZEN) { case CPU_UP_PREPARE: - BUG_ON(stopper->thread || stopper->enabled || - !list_empty(&stopper->works)); + BUG_ON(p || stopper->enabled || !list_empty(&stopper->works)); p = kthread_create_on_node(cpu_stopper_thread, stopper, cpu_to_node(cpu), @@ -319,12 +319,12 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, get_task_struct(p); kthread_bind(p, cpu); sched_set_stop_task(cpu, p); - stopper->thread = p; + per_cpu(cpu_stopper_task, cpu) = p; break; case CPU_ONLINE: /* strictly unnecessary, as first user will wake it */ - wake_up_process(stopper->thread); + wake_up_process(p); /* mark enabled */ spin_lock_irq(&stopper->lock); stopper->enabled = true; @@ -339,7 +339,7 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, sched_set_stop_task(cpu, NULL); /* kill the stopper */ - kthread_stop(stopper->thread); + kthread_stop(p); /* drain remaining works */ spin_lock_irq(&stopper->lock); list_for_each_entry(work, &stopper->works, list) @@ -347,8 +347,8 @@ static int __cpuinit cpu_stop_cpu_callback(struct notifier_block *nfb, stopper->enabled = false; spin_unlock_irq(&stopper->lock); /* release the stopper */ - put_task_struct(stopper->thread); - stopper->thread = NULL; + put_task_struct(p); + per_cpu(cpu_stopper_task, cpu) = NULL; break; } #endif |