diff options
Diffstat (limited to 'lib/percpu-refcount.c')
| -rw-r--r-- | lib/percpu-refcount.c | 56 |
1 files changed, 29 insertions, 27 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 8ef3f5c20df6..5aea6b7356c7 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); |