nfsd: move fsid_type choice out of fh_compose
[safe/jmp/linux-2.6] / lib / percpu_counter.c
index 3b0ed80..aeaa6d7 100644 (file)
@@ -9,10 +9,8 @@
 #include <linux/cpu.h>
 #include <linux/module.h>
 
-#ifdef CONFIG_HOTPLUG_CPU
 static LIST_HEAD(percpu_counters);
 static DEFINE_MUTEX(percpu_counters_lock);
-#endif
 
 void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
 {
@@ -68,37 +66,57 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
 }
 EXPORT_SYMBOL(__percpu_counter_sum);
 
-void percpu_counter_init(struct percpu_counter *fbc, s64 amount)
+int __percpu_counter_init(struct percpu_counter *fbc, s64 amount,
+                         struct lock_class_key *key)
 {
        spin_lock_init(&fbc->lock);
+       lockdep_set_class(&fbc->lock, key);
        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);
+EXPORT_SYMBOL(__percpu_counter_init);
 
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
-       free_percpu(fbc->counters);
+       if (!fbc->counters)
+               return;
+
 #ifdef CONFIG_HOTPLUG_CPU
        mutex_lock(&percpu_counters_lock);
        list_del(&fbc->list);
        mutex_unlock(&percpu_counters_lock);
 #endif
+       free_percpu(fbc->counters);
+       fbc->counters = NULL;
 }
 EXPORT_SYMBOL(percpu_counter_destroy);
 
-#ifdef CONFIG_HOTPLUG_CPU
+int percpu_counter_batch __read_mostly = 32;
+EXPORT_SYMBOL(percpu_counter_batch);
+
+static void compute_batch_value(void)
+{
+       int nr = num_online_cpus();
+
+       percpu_counter_batch = max(32, nr*2);
+}
+
 static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
                                        unsigned long action, void *hcpu)
 {
+#ifdef CONFIG_HOTPLUG_CPU
        unsigned int cpu;
        struct percpu_counter *fbc;
 
+       compute_batch_value();
        if (action != CPU_DEAD)
                return NOTIFY_OK;
 
@@ -106,21 +124,23 @@ 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);
+#endif
        return NOTIFY_OK;
 }
 
 static int __init percpu_counter_startup(void)
 {
+       compute_batch_value();
        hotcpu_notifier(percpu_counter_hotcpu_callback, 0);
        return 0;
 }
 module_init(percpu_counter_startup);
-#endif