On Tue, Sep 23, 2014 at 01:55:12AM -0400, Tejun Heo wrote: > percpu_ref uses pcpu_ prefix for internal stuff and percpu_ for > externally visible ones. This is the same convention used in the > percpu allocator implementation. It works fine there but percpu_ref > doesn't have too much internal-only stuff and scattered usages of > pcpu_ prefix are confusing than helpful. > > This patch replaces all pcpu_ prefixes with percpu_. This is pure > rename and there's no functional change. Note that PCPU_REF_DEAD is > renamed to __PERCPU_REF_DEAD to signify that the flag is internal. > > Signed-off-by: Tejun Heo <t...@kernel.org> > Cc: Kent Overstreet <k...@daterainc.com>
Reviewed-by: Kent Overstreet <k...@daterainc.com> > --- > include/linux/percpu-refcount.h | 46 ++++++++++++++++----------------- > 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); > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/