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locking, percpu_counter: Annotate ::lock as raw

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The percpu_counter::lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner 2009-07-25 16:21:48 +02:00 committed by Ingo Molnar
parent ec484608c5
commit f032a45081
2 changed files with 10 additions and 10 deletions
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2
include/linux/percpu_counter.h
View File

@ -16,7 +16,7 @@
#ifdef CONFIG_SMP
struct percpu_counter {
spinlock_t lock;
raw_spinlock_t lock;
s64 count;
#ifdef CONFIG_HOTPLUG_CPU
struct list_head list; /* All percpu_counters are on a list */

18
lib/percpu_counter.c
View File

@ -59,13 +59,13 @@ void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
{
int cpu;
spin_lock(&fbc->lock);
raw_spin_lock(&fbc->lock);
for_each_possible_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
*pcount = 0;
}
fbc->count = amount;
spin_unlock(&fbc->lock);
raw_spin_unlock(&fbc->lock);
}
EXPORT_SYMBOL(percpu_counter_set);
@ -76,10 +76,10 @@ void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
preempt_disable();
count = __this_cpu_read(*fbc->counters) + amount;
if (count >= batch || count <= -batch) {
spin_lock(&fbc->lock);
raw_spin_lock(&fbc->lock);
fbc->count += count;
__this_cpu_write(*fbc->counters, 0);
spin_unlock(&fbc->lock);
raw_spin_unlock(&fbc->lock);
} else {
__this_cpu_write(*fbc->counters, count);
}
@ -96,13 +96,13 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
s64 ret;
int cpu;
spin_lock(&fbc->lock);
raw_spin_lock(&fbc->lock);
ret = fbc->count;
for_each_online_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
ret += *pcount;
}
spin_unlock(&fbc->lock);
raw_spin_unlock(&fbc->lock);
return ret;
}
EXPORT_SYMBOL(__percpu_counter_sum);
@ -110,7 +110,7 @@ EXPORT_SYMBOL(__percpu_counter_sum);
int __percpu_counter_init(struct percpu_counter *fbc, s64 amount,
struct lock_class_key *key)
{
spin_lock_init(&fbc->lock);
raw_spin_lock_init(&fbc->lock);
lockdep_set_class(&fbc->lock, key);
fbc->count = amount;
fbc->counters = alloc_percpu(s32);
@ -173,11 +173,11 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
s32 *pcount;
unsigned long flags;
spin_lock_irqsave(&fbc->lock, flags);
raw_spin_lock_irqsave(&fbc->lock, flags);
pcount = per_cpu_ptr(fbc->counters, cpu);
fbc->count += *pcount;
*pcount = 0;
spin_unlock_irqrestore(&fbc->lock, flags);
raw_spin_unlock_irqrestore(&fbc->lock, flags);
}
mutex_unlock(&percpu_counters_lock);
#endif