Re: [PATCH 1/9] percpu_ref: relocate percpu_ref_reinit()

Kent Overstreet
2014-09-23T20:59:47Z

On Tue, Sep 23, 2014 at 01:55:10AM -0400, Tejun Heo wrote:
> percpu_ref is gonna go through restructuring. Move
> percpu_ref_reinit() after percpu_ref_kill_and_confirm(). This will
> make later changes easier to follow and result in cleaner
> organization.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Kent Overstreet <kmo@daterainc.com>

Reviewed-by: Kent Overstreet <kmo@daterainc.com>

> ---
> include/linux/percpu-refcount.h | 2 +-
> lib/percpu-refcount.c | 70 ++++++++++++++++++++---------------------
> 2 files changed, 36 insertions(+), 36 deletions(-)
>
> diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h
> index 5df6784..f015f13 100644
> --- a/include/linux/percpu-refcount.h
> +++ b/include/linux/percpu-refcount.h
> @@ -68,10 +68,10 @@ struct percpu_ref {
>
> int __must_check percpu_ref_init(struct percpu_ref *ref,
> percpu_ref_func_t *release, gfp_t gfp);
> -void percpu_ref_reinit(struct percpu_ref *ref);
> void percpu_ref_exit(struct percpu_ref *ref);
> void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
> percpu_ref_func_t *confirm_kill);
> +void percpu_ref_reinit(struct percpu_ref *ref);
>
> /**
> * percpu_ref_kill - drop the initial ref
> diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
> index 559ee0b..070dab5 100644
> --- a/lib/percpu-refcount.c
> +++ b/lib/percpu-refcount.c
> @@ -63,41 +63,6 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
> EXPORT_SYMBOL_GPL(percpu_ref_init);
>
> /**
> - * percpu_ref_reinit - re-initialize a percpu refcount
> - * @ref: perpcu_ref to re-initialize
> - *
> - * Re-initialize @ref so that it's in the same state as when it finished
> - * percpu_ref_init(). @ref must have been initialized successfully, killed
> - * and reached 0 but not exited.
> - *
> - * Note that percpu_ref_tryget[_live]() are safe to perform on @ref while
> - * this function is in progress.
> - */
> -void percpu_ref_reinit(struct percpu_ref *ref)
> -{
> - unsigned long __percpu *pcpu_count = pcpu_count_ptr(ref);
> - int cpu;
> -
> - BUG_ON(!pcpu_count);
> - WARN_ON(!percpu_ref_is_zero(ref));
> -
> - atomic_long_set(&ref->count, 1 + PCPU_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.
> - */
> - for_each_possible_cpu(cpu)
> - *per_cpu_ptr(pcpu_count, cpu) = 0;
> -
> - smp_store_release(&ref->pcpu_count_ptr,
> - ref->pcpu_count_ptr & ~PCPU_REF_DEAD);
> -}
> -EXPORT_SYMBOL_GPL(percpu_ref_reinit);
> -
> -/**
> * percpu_ref_exit - undo percpu_ref_init()
> * @ref: percpu_ref to exit
> *
> @@ -189,3 +154,38 @@ void percpu_ref_kill_and_confirm(struct percpu_ref *ref,
> call_rcu_sched(&ref->rcu, percpu_ref_kill_rcu);
> }
> EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm);
> +
> +/**
> + * percpu_ref_reinit - re-initialize a percpu refcount
> + * @ref: perpcu_ref to re-initialize
> + *
> + * Re-initialize @ref so that it's in the same state as when it finished
> + * percpu_ref_init(). @ref must have been initialized successfully, killed
> + * and reached 0 but not exited.
> + *
> + * Note that percpu_ref_tryget[_live]() are safe to perform on @ref while
> + * this function is in progress.
> + */
> +void percpu_ref_reinit(struct percpu_ref *ref)
> +{
> + unsigned long __percpu *pcpu_count = pcpu_count_ptr(ref);
> + int cpu;
> +
> + BUG_ON(!pcpu_count);
> + WARN_ON(!percpu_ref_is_zero(ref));
> +
> + atomic_long_set(&ref->count, 1 + PCPU_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.
> + */
> + for_each_possible_cpu(cpu)
> + *per_cpu_ptr(pcpu_count, cpu) = 0;
> +
> + smp_store_release(&ref->pcpu_count_ptr,
> + ref->pcpu_count_ptr & ~PCPU_REF_DEAD);
> +}
> +EXPORT_SYMBOL_GPL(percpu_ref_reinit);
> --
> 1.9.3
>