diff options
| -rw-r--r-- | include/linux/percpu-refcount.h | 46 | ||||
| -rw-r--r-- | lib/percpu-refcount.c | 56 |
2 files changed, 52 insertions, 50 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index d44b027..3d463a3 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -13,7 +13,7 @@ * * The refcount will have a range of 0 to ((1U << 31) - 1), i.e. one bit less * than an atomic_t - this is because of the way shutdown works, see - * percpu_ref_kill()/PCPU_COUNT_BIAS. + * percpu_ref_kill()/PERCPU_COUNT_BIAS. * * Before you call percpu_ref_kill(), percpu_ref_put() does not check for the * refcount hitting 0 - it can't, if it was in percpu mode. percpu_ref_kill() @@ -60,7 +60,7 @@ struct percpu_ref { * The low bit of the pointer indicates whether the ref is in percpu * mode; if set, then get/put will manipulate the atomic_t. */ - unsigned long pcpu_count_ptr; + unsigned long percpu_count_ptr; percpu_ref_func_t *release; percpu_ref_func_t *confirm_kill; struct rcu_head rcu; @@ -88,26 +88,26 @@ static inline void percpu_ref_kill(struct percpu_ref *ref) return percpu_ref_kill_and_confirm(ref, NULL); } -#define PCPU_REF_DEAD 1 +#define __PERCPU_REF_DEAD 1 /* * Internal helper. Don't use outside percpu-refcount proper. The * function doesn't return the pointer and let the caller test it for NULL * because doing so forces the compiler to generate two conditional - * branches as it can't assume that @ref->pcpu_count is not NULL. + * branches as it can't assume that @ref->percpu_count is not NULL. */ -static inline bool __pcpu_ref_alive(struct percpu_ref *ref, - unsigned long __percpu **pcpu_countp) +static inline bool __percpu_ref_alive(struct percpu_ref *ref, + unsigned long __percpu **percpu_countp) { - unsigned long pcpu_ptr = ACCESS_ONCE(ref->pcpu_count_ptr); + unsigned long percpu_ptr = ACCESS_ONCE(ref->percpu_count_ptr); /* paired with smp_store_release() in percpu_ref_reinit() */ smp_read_barrier_depends(); - if (unlikely(pcpu_ptr & PCPU_REF_DEAD)) + if (unlikely(percpu_ptr & __PERCPU_REF_DEAD)) return false; - *pcpu_countp = (unsigned long __percpu *)pcpu_ptr; + *percpu_countp = (unsigned long __percpu *)percpu_ptr; return true; } @@ -121,12 +121,12 @@ static inline bool __pcpu_ref_alive(struct percpu_ref *ref, */ static inline void percpu_ref_get(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count; + unsigned long __percpu *percpu_count; rcu_read_lock_sched(); - if (__pcpu_ref_alive(ref, &pcpu_count)) - this_cpu_inc(*pcpu_count); + if (__percpu_ref_alive(ref, &percpu_count)) + this_cpu_inc(*percpu_count); else atomic_long_inc(&ref->count); @@ -144,13 +144,13 @@ static inline void percpu_ref_get(struct percpu_ref *ref) */ static inline bool percpu_ref_tryget(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count; + unsigned long __percpu *percpu_count; int ret; rcu_read_lock_sched(); - if (__pcpu_ref_alive(ref, &pcpu_count)) { - this_cpu_inc(*pcpu_count); + if (__percpu_ref_alive(ref, &percpu_count)) { + this_cpu_inc(*percpu_count); ret = true; } else { ret = atomic_long_inc_not_zero(&ref->count); @@ -178,13 +178,13 @@ static inline bool percpu_ref_tryget(struct percpu_ref *ref) */ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count; + unsigned long __percpu *percpu_count; int ret = false; rcu_read_lock_sched(); - if (__pcpu_ref_alive(ref, &pcpu_count)) { - this_cpu_inc(*pcpu_count); + if (__percpu_ref_alive(ref, &percpu_count)) { + this_cpu_inc(*percpu_count); ret = true; } @@ -204,12 +204,12 @@ static inline bool percpu_ref_tryget_live(struct percpu_ref *ref) */ static inline void percpu_ref_put(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count; + unsigned long __percpu *percpu_count; rcu_read_lock_sched(); - if (__pcpu_ref_alive(ref, &pcpu_count)) - this_cpu_dec(*pcpu_count); + if (__percpu_ref_alive(ref, &percpu_count)) + this_cpu_dec(*percpu_count); else if (unlikely(atomic_long_dec_and_test(&ref->count))) ref->release(ref); @@ -226,9 +226,9 @@ static inline void percpu_ref_put(struct percpu_ref *ref) */ static inline bool percpu_ref_is_zero(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count; + unsigned long __percpu *percpu_count; - if (__pcpu_ref_alive(ref, &pcpu_count)) + if (__percpu_ref_alive(ref, &percpu_count)) return false; return !atomic_long_read(&ref->count); } diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 8ef3f5c..5aea6b7 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -11,8 +11,8 @@ * percpu counters will all sum to the correct value * * (More precisely: because moduler arithmatic is commutative the sum of all the - * pcpu_count vars will be equal to what it would have been if all the gets and - * puts were done to a single integer, even if some of the percpu integers + * percpu_count vars will be equal to what it would have been if all the gets + * and puts were done to a single integer, even if some of the percpu integers * overflow or underflow). * * The real trick to implementing percpu refcounts is shutdown. We can't detect @@ -29,11 +29,12 @@ * atomic_long_t can't hit 0 before we've added up all the percpu refs. */ -#define PCPU_COUNT_BIAS (1LU << (BITS_PER_LONG - 1)) +#define PERCPU_COUNT_BIAS (1LU << (BITS_PER_LONG - 1)) -static unsigned long __percpu *pcpu_count_ptr(struct percpu_ref *ref) +static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref) { - return (unsigned long __percpu *)(ref->pcpu_count_ptr & ~PCPU_REF_DEAD); + return (unsigned long __percpu *) + (ref->percpu_count_ptr & ~__PERCPU_REF_DEAD); } /** @@ -51,10 +52,11 @@ static unsigned long __percpu *pcpu_count_ptr(struct percpu_ref *ref) int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release, gfp_t gfp) { - atomic_long_set(&ref->count, 1 + PCPU_COUNT_BIAS); + atomic_long_set(&ref->count, 1 + PERCPU_COUNT_BIAS); - ref->pcpu_count_ptr = (unsigned long)alloc_percpu_gfp(unsigned long, gfp); - if (!ref->pcpu_count_ptr) + ref->percpu_count_ptr = + (unsigned long)alloc_percpu_gfp(unsigned long, gfp); + if (!ref->percpu_count_ptr) return -ENOMEM; ref->release = release; @@ -74,11 +76,11 @@ EXPORT_SYMBOL_GPL(percpu_ref_init); */ void percpu_ref_exit(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count = pcpu_count_ptr(ref); + unsigned long __percpu *percpu_count = percpu_count_ptr(ref); - if (pcpu_count) { - free_percpu(pcpu_count); - ref->pcpu_count_ptr = PCPU_REF_DEAD; + if (percpu_count) { + free_percpu(percpu_count); + ref->percpu_count_ptr = __PERCPU_REF_DEAD; } } EXPORT_SYMBOL_GPL(percpu_ref_exit); @@ -86,14 +88,14 @@ EXPORT_SYMBOL_GPL(percpu_ref_exit); static void percpu_ref_kill_rcu(struct rcu_head *rcu) { struct percpu_ref *ref = container_of(rcu, struct percpu_ref, rcu); - unsigned long __percpu *pcpu_count = pcpu_count_ptr(ref); + unsigned long __percpu *percpu_count = percpu_count_ptr(ref); unsigned long count = 0; int cpu; for_each_possible_cpu(cpu) - count += *per_cpu_ptr(pcpu_count, cpu); + count += *per_cpu_ptr(percpu_count, cpu); - pr_debug("global %ld pcpu %ld", + pr_debug("global %ld percpu %ld", atomic_long_read(&ref->count), (long)count); /* @@ -108,7 +110,7 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) * reaching 0 before we add the percpu counts. But doing it at the same * time is equivalent and saves us atomic operations: */ - atomic_long_add((long)count - PCPU_COUNT_BIAS, &ref->count); + atomic_long_add((long)count - PERCPU_COUNT_BIAS, &ref->count); WARN_ONCE(atomic_long_read(&ref->count) <= 0, "percpu ref (%pf) <= 0 (%ld) after killed", @@ -143,10 +145,10 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill) { - WARN_ONCE(ref->pcpu_count_ptr & PCPU_REF_DEAD, + WARN_ONCE(ref->percpu_count_ptr & __PERCPU_REF_DEAD, "%s called more than once on %pf!", __func__, ref->release); - ref->pcpu_count_ptr |= PCPU_REF_DEAD; + ref->percpu_count_ptr |= __PERCPU_REF_DEAD; ref->confirm_kill = confirm_kill; call_rcu_sched(&ref->rcu, percpu_ref_kill_rcu); @@ -166,24 +168,24 @@ EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm); */ void percpu_ref_reinit(struct percpu_ref *ref) { - unsigned long __percpu *pcpu_count = pcpu_count_ptr(ref); + unsigned long __percpu *percpu_count = percpu_count_ptr(ref); int cpu; - BUG_ON(!pcpu_count); + BUG_ON(!percpu_count); WARN_ON_ONCE(!percpu_ref_is_zero(ref)); - atomic_long_set(&ref->count, 1 + PCPU_COUNT_BIAS); + atomic_long_set(&ref->count, 1 + PERCPU_COUNT_BIAS); /* * Restore per-cpu operation. smp_store_release() is paired with - * smp_read_barrier_depends() in __pcpu_ref_alive() and guarantees - * that the zeroing is visible to all percpu accesses which can see - * the following PCPU_REF_DEAD clearing. + * smp_read_barrier_depends() in __percpu_ref_alive() and + * guarantees that the zeroing is visible to all percpu accesses + * which can see the following __PERCPU_REF_DEAD clearing. */ for_each_possible_cpu(cpu) - *per_cpu_ptr(pcpu_count, cpu) = 0; + *per_cpu_ptr(percpu_count, cpu) = 0; - smp_store_release(&ref->pcpu_count_ptr, - ref->pcpu_count_ptr & ~PCPU_REF_DEAD); + smp_store_release(&ref->percpu_count_ptr, + ref->percpu_count_ptr & ~__PERCPU_REF_DEAD); } EXPORT_SYMBOL_GPL(percpu_ref_reinit); |
