Commit 9f5a5621 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

smp: Convert smplocks to raw_spinlocks 



Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
parent d209d74d

kernel/smp.c

+16 −16
Original line number Diff line number Diff line
@@ -16,11 +16,11 @@ static DEFINE_PER_CPU(struct call_single_queue, call_single_queue); 


static struct {

	struct list_head	queue;

	spinlock_t		lock;

	raw_spinlock_t		lock;

} call_function __cacheline_aligned_in_smp =

	{

		.queue		= LIST_HEAD_INIT(call_function.queue),

		.lock		= __SPIN_LOCK_UNLOCKED(call_function.lock),

		.lock		= __RAW_SPIN_LOCK_UNLOCKED(call_function.lock),

	};



enum {
@@ -35,7 +35,7 @@ struct call_function_data { 


struct call_single_queue {

	struct list_head	list;

	spinlock_t		lock;

	raw_spinlock_t		lock;

};



static DEFINE_PER_CPU(struct call_function_data, cfd_data);
@@ -80,7 +80,7 @@ static int __cpuinit init_call_single_data(void) 
	for_each_possible_cpu(i) {

		struct call_single_queue *q = &per_cpu(call_single_queue, i);



		spin_lock_init(&q->lock);

		raw_spin_lock_init(&q->lock);

		INIT_LIST_HEAD(&q->list);

	}
@@ -141,10 +141,10 @@ void generic_exec_single(int cpu, struct call_single_data *data, int wait) 
	unsigned long flags;

	int ipi;



	spin_lock_irqsave(&dst->lock, flags);

	raw_spin_lock_irqsave(&dst->lock, flags);

	ipi = list_empty(&dst->list);

	list_add_tail(&data->list, &dst->list);

	spin_unlock_irqrestore(&dst->lock, flags);

	raw_spin_unlock_irqrestore(&dst->lock, flags);



	/*

	 * The list addition should be visible before sending the IPI
@@ -201,9 +201,9 @@ void generic_smp_call_function_interrupt(void) 
		refs = atomic_dec_return(&data->refs);

		WARN_ON(refs < 0);

		if (!refs) {

			spin_lock(&call_function.lock);

			raw_spin_lock(&call_function.lock);

			list_del_rcu(&data->csd.list);

			spin_unlock(&call_function.lock);

			raw_spin_unlock(&call_function.lock);

		}



		if (refs)
@@ -230,9 +230,9 @@ void generic_smp_call_function_single_interrupt(void) 
	 */

	WARN_ON_ONCE(!cpu_online(smp_processor_id()));



	spin_lock(&q->lock);

	raw_spin_lock(&q->lock);

	list_replace_init(&q->list, &list);

	spin_unlock(&q->lock);

	raw_spin_unlock(&q->lock);



	while (!list_empty(&list)) {

		struct call_single_data *data;
@@ -449,14 +449,14 @@ void smp_call_function_many(const struct cpumask *mask, 
	cpumask_clear_cpu(this_cpu, data->cpumask);

	atomic_set(&data->refs, cpumask_weight(data->cpumask));



	spin_lock_irqsave(&call_function.lock, flags);

	raw_spin_lock_irqsave(&call_function.lock, flags);

	/*

	 * Place entry at the _HEAD_ of the list, so that any cpu still

	 * observing the entry in generic_smp_call_function_interrupt()

	 * will not miss any other list entries:

	 */

	list_add_rcu(&data->csd.list, &call_function.queue);

	spin_unlock_irqrestore(&call_function.lock, flags);

	raw_spin_unlock_irqrestore(&call_function.lock, flags);



	/*

	 * Make the list addition visible before sending the ipi.
@@ -501,20 +501,20 @@ EXPORT_SYMBOL(smp_call_function); 


void ipi_call_lock(void)

{

	spin_lock(&call_function.lock);

	raw_spin_lock(&call_function.lock);

}



void ipi_call_unlock(void)

{

	spin_unlock(&call_function.lock);

	raw_spin_unlock(&call_function.lock);

}



void ipi_call_lock_irq(void)

{

	spin_lock_irq(&call_function.lock);

	raw_spin_lock_irq(&call_function.lock);

}



void ipi_call_unlock_irq(void)

{

	spin_unlock_irq(&call_function.lock);

	raw_spin_unlock_irq(&call_function.lock);

}