X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fpercpu_counter.c;h=393a0e915c23b252b747c62645beb463e25843ed;hb=b5677d848cbb94220ac2cfd36d93bcdbe49c3280;hp=c9708db9b8d320b4893f1c4a59f9200c725a0f3d;hpb=3a587f47b82f96f19318c036e7b979fcd5c3848f;p=linux-2.6

diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index c9708db9b8..393a0e915c 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -52,7 +52,7 @@ EXPORT_SYMBOL(__percpu_counter_add);
  * Add up all the per-cpu counts, return the result.  This is a more accurate
  * but much slower version of percpu_counter_read_positive()
  */
-s64 percpu_counter_sum(struct percpu_counter *fbc)
+s64 __percpu_counter_sum(struct percpu_counter *fbc)
 {
 	s64 ret;
 	int cpu;
@@ -64,25 +64,43 @@ s64 percpu_counter_sum(struct percpu_counter *fbc)
 		ret += *pcount;
 	}
 	spin_unlock(&fbc->lock);
-	return ret < 0 ? 0 : ret;
+	return ret;
 }
-EXPORT_SYMBOL(percpu_counter_sum);
+EXPORT_SYMBOL(__percpu_counter_sum);
 
-void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+static struct lock_class_key percpu_counter_irqsafe;
+
+int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {
 	spin_lock_init(&fbc->lock);
 	fbc->count = amount;
 	fbc->counters = alloc_percpu(s32);
+	if (!fbc->counters)
+		return -ENOMEM;
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_lock(&percpu_counters_lock);
 	list_add(&fbc->list, &percpu_counters);
 	mutex_unlock(&percpu_counters_lock);
 #endif
+	return 0;
 }
 EXPORT_SYMBOL(percpu_counter_init);
 
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount)
+{
+	int err;
+
+	err = percpu_counter_init(fbc, amount);
+	if (!err)
+		lockdep_set_class(&fbc->lock, &percpu_counter_irqsafe);
+	return err;
+}
+
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
+	if (!fbc->counters)
+		return;
+
 	free_percpu(fbc->counters);
 #ifdef CONFIG_HOTPLUG_CPU
 	mutex_lock(&percpu_counters_lock);
@@ -106,12 +124,13 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
 	mutex_lock(&percpu_counters_lock);
 	list_for_each_entry(fbc, &percpu_counters, list) {
 		s32 *pcount;
+		unsigned long flags;
 
-		spin_lock(&fbc->lock);
+		spin_lock_irqsave(&fbc->lock, flags);
 		pcount = per_cpu_ptr(fbc->counters, cpu);
 		fbc->count += *pcount;
 		*pcount = 0;
-		spin_unlock(&fbc->lock);
+		spin_unlock_irqrestore(&fbc->lock, flags);
 	}
 	mutex_unlock(&percpu_counters_lock);
 	return NOTIFY_OK;