diff options
| -rw-r--r-- | include/linux/percpu_counter.h | 18 | ||||
| -rw-r--r-- | lib/percpu_counter.c | 66 |
2 files changed, 72 insertions, 12 deletions
diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index f5aa593ccf32..3d9f70972cdf 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -8,6 +8,7 @@ #include <linux/spinlock.h> #include <linux/smp.h> +#include <linux/list.h> #include <linux/threads.h> #include <linux/percpu.h> #include <linux/types.h> @@ -17,6 +18,9 @@ struct percpu_counter { spinlock_t lock; s64 count; +#ifdef CONFIG_HOTPLUG_CPU + struct list_head list; /* All percpu_counters are on a list */ +#endif s32 *counters; }; @@ -26,18 +30,8 @@ struct percpu_counter { #define FBC_BATCH (NR_CPUS*4) #endif -static inline void percpu_counter_init(struct percpu_counter *fbc, s64 amount) -{ - spin_lock_init(&fbc->lock); - fbc->count = amount; - fbc->counters = alloc_percpu(s32); -} - -static inline void percpu_counter_destroy(struct percpu_counter *fbc) -{ - free_percpu(fbc->counters); -} - +void percpu_counter_init(struct percpu_counter *fbc, s64 amount); +void percpu_counter_destroy(struct percpu_counter *fbc); void percpu_counter_mod(struct percpu_counter *fbc, s32 amount); s64 percpu_counter_sum(struct percpu_counter *fbc); diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 850449080e1c..8901c4e9c2e6 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -3,8 +3,17 @@ */ #include <linux/percpu_counter.h> +#include <linux/notifier.h> +#include <linux/mutex.h> +#include <linux/init.h> +#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_mod(struct percpu_counter *fbc, s32 amount) { long count; @@ -44,3 +53,60 @@ s64 percpu_counter_sum(struct percpu_counter *fbc) return ret < 0 ? 0 : ret; } EXPORT_SYMBOL(percpu_counter_sum); + +void percpu_counter_init(struct percpu_counter *fbc, s64 amount) +{ + spin_lock_init(&fbc->lock); + fbc->count = amount; + fbc->counters = alloc_percpu(s32); +#ifdef CONFIG_HOTPLUG_CPU + mutex_lock(&percpu_counters_lock); + list_add(&fbc->list, &percpu_counters); + mutex_unlock(&percpu_counters_lock); +#endif +} +EXPORT_SYMBOL(percpu_counter_init); + +void percpu_counter_destroy(struct percpu_counter *fbc) +{ + free_percpu(fbc->counters); +#ifdef CONFIG_HOTPLUG_CPU + mutex_lock(&percpu_counters_lock); + list_del(&fbc->list); + mutex_unlock(&percpu_counters_lock); +#endif +} +EXPORT_SYMBOL(percpu_counter_destroy); + +#ifdef CONFIG_HOTPLUG_CPU +static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb, + unsigned long action, void *hcpu) +{ + unsigned int cpu; + struct percpu_counter *fbc; + + if (action != CPU_DEAD) + return NOTIFY_OK; + + cpu = (unsigned long)hcpu; + mutex_lock(&percpu_counters_lock); + list_for_each_entry(fbc, &percpu_counters, list) { + s32 *pcount; + + spin_lock(&fbc->lock); + pcount = per_cpu_ptr(fbc->counters, cpu); + fbc->count += *pcount; + *pcount = 0; + spin_unlock(&fbc->lock); + } + mutex_unlock(&percpu_counters_lock); + return NOTIFY_OK; +} + +static int __init percpu_counter_startup(void) +{ + hotcpu_notifier(percpu_counter_hotcpu_callback, 0); + return 0; +} +module_init(percpu_counter_startup); +#endif |
