From d87aae2f3c8e90bd0fe03f5309b4d066b712b8ec Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 31 Jul 2012 09:28:31 +0400 Subject: switch the protection of percpu_counter list to spinlock ... making percpu_counter_destroy() non-blocking Signed-off-by: Al Viro --- lib/percpu_counter.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index f8a3f1a829b8..ba6085d9c741 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -12,7 +12,7 @@ #ifdef CONFIG_HOTPLUG_CPU static LIST_HEAD(percpu_counters); -static DEFINE_MUTEX(percpu_counters_lock); +static DEFINE_SPINLOCK(percpu_counters_lock); #endif #ifdef CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER @@ -123,9 +123,9 @@ int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, #ifdef CONFIG_HOTPLUG_CPU INIT_LIST_HEAD(&fbc->list); - mutex_lock(&percpu_counters_lock); + spin_lock(&percpu_counters_lock); list_add(&fbc->list, &percpu_counters); - mutex_unlock(&percpu_counters_lock); + spin_unlock(&percpu_counters_lock); #endif return 0; } @@ -139,9 +139,9 @@ void percpu_counter_destroy(struct percpu_counter *fbc) debug_percpu_counter_deactivate(fbc); #ifdef CONFIG_HOTPLUG_CPU - mutex_lock(&percpu_counters_lock); + spin_lock(&percpu_counters_lock); list_del(&fbc->list); - mutex_unlock(&percpu_counters_lock); + spin_unlock(&percpu_counters_lock); #endif free_percpu(fbc->counters); fbc->counters = NULL; @@ -170,7 +170,7 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb, return NOTIFY_OK; cpu = (unsigned long)hcpu; - mutex_lock(&percpu_counters_lock); + spin_lock(&percpu_counters_lock); list_for_each_entry(fbc, &percpu_counters, list) { s32 *pcount; unsigned long flags; @@ -181,7 +181,7 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb, *pcount = 0; raw_spin_unlock_irqrestore(&fbc->lock, flags); } - mutex_unlock(&percpu_counters_lock); + spin_unlock(&percpu_counters_lock); #endif return NOTIFY_OK; } -- cgit v1.2.2