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-rw-r--r--lib/percpu-refcount.c23
1 files changed, 18 insertions, 5 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 5a6d43baccc5..ed280fb1e5b5 100644
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -45,27 +45,40 @@ static unsigned long __percpu *percpu_count_ptr(struct percpu_ref *ref)
* percpu_ref_init - initialize a percpu refcount
* @ref: percpu_ref to initialize
* @release: function which will be called when refcount hits 0
+ * @flags: PERCPU_REF_INIT_* flags
* @gfp: allocation mask to use
*
- * Initializes the refcount in single atomic counter mode with a refcount of 1;
- * analagous to atomic_long_set(ref, 1).
+ * Initializes @ref. If @flags is zero, @ref starts in percpu mode with a
+ * refcount of 1; analagous to atomic_long_set(ref, 1). See the
+ * definitions of PERCPU_REF_INIT_* flags for flag behaviors.
*
* Note that @release must not sleep - it may potentially be called from RCU
* callback context by percpu_ref_kill().
*/
int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
- gfp_t gfp)
+ unsigned int flags, gfp_t gfp)
{
size_t align = max_t(size_t, 1 << __PERCPU_REF_FLAG_BITS,
__alignof__(unsigned long));
-
- atomic_long_set(&ref->count, 1 + PERCPU_COUNT_BIAS);
+ unsigned long start_count = 0;
ref->percpu_count_ptr = (unsigned long)
__alloc_percpu_gfp(sizeof(unsigned long), align, gfp);
if (!ref->percpu_count_ptr)
return -ENOMEM;
+ if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD))
+ ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;
+ else
+ start_count += PERCPU_COUNT_BIAS;
+
+ if (flags & PERCPU_REF_INIT_DEAD)
+ ref->percpu_count_ptr |= __PERCPU_REF_DEAD;
+ else
+ start_count++;
+
+ atomic_long_set(&ref->count, start_count);
+
ref->release = release;
return 0;
}