Messages in this thread Patch in this message | | | Date | Thu, 13 Nov 2014 17:04:53 -0500 | From | Tejun Heo <> | Subject | [PATCH percpu/for-3.19 2/2] percpu_ref: implement percpu_ref_is_dying() |
| |
Implement percpu_ref_is_dying() which tests whether the ref is dying or dead. This is useful to determine the current state when a percpu_ref is used as a cyclic on/off switch via kill and reinit.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kent Overstreet <kmo@daterainc.com> --- include/linux/percpu-refcount.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
--- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -258,6 +258,20 @@ static inline void percpu_ref_put(struct } /** + * percpu_ref_is_dying - test whether a percpu refcount is dying or dead + * @ref: percpu_ref to test + * + * Returns %true if @ref is dying or dead. + * + * This function is safe to call as long as @ref is between init and exit + * and the caller is responsible for synchronizing against state changes. + */ +static inline bool percpu_ref_is_dying(struct percpu_ref *ref) +{ + return ref->percpu_count_ptr & __PERCPU_REF_DEAD; +} + +/** * percpu_ref_is_zero - test whether a percpu refcount reached zero * @ref: percpu_ref to test *
| |