diff options
| author | Roman Gushchin <guro@fb.com> | 2019-05-07 10:01:50 -0700 |
|---|---|---|
| committer | Dennis Zhou <dennis@kernel.org> | 2019-05-09 10:51:06 -0700 |
| commit | 7d9ab9b6adffd9c474c1274acb5f6208f9a09cf3 (patch) | |
| tree | 461ee811d60454e5e21fb6f567ec2e2435575a12 /lib/percpu-refcount.c | |
| parent | ddde2af747ad79010f14691f381522987fbcb860 (diff) | |
| download | lwn-7d9ab9b6adffd9c474c1274acb5f6208f9a09cf3.tar.gz lwn-7d9ab9b6adffd9c474c1274acb5f6208f9a09cf3.zip | |
percpu_ref: release percpu memory early without PERCPU_REF_ALLOW_REINIT
Release percpu memory after finishing the switch to the atomic mode
if only PERCPU_REF_ALLOW_REINIT isn't set.
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Diffstat (limited to 'lib/percpu-refcount.c')
| -rw-r--r-- | lib/percpu-refcount.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 9877682e49c7..501b517bd3db 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -69,11 +69,14 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release, return -ENOMEM; ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC; + ref->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT; - if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) + if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) { ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC; - else + ref->allow_reinit = true; + } else { start_count += PERCPU_COUNT_BIAS; + } if (flags & PERCPU_REF_INIT_DEAD) ref->percpu_count_ptr |= __PERCPU_REF_DEAD; @@ -119,6 +122,9 @@ static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu) ref->confirm_switch = NULL; wake_up_all(&percpu_ref_switch_waitq); + if (!ref->allow_reinit) + percpu_ref_exit(ref); + /* drop ref from percpu_ref_switch_to_atomic() */ percpu_ref_put(ref); } @@ -194,6 +200,9 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref) if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC)) return; + if (WARN_ON_ONCE(!ref->allow_reinit)) + return; + atomic_long_add(PERCPU_COUNT_BIAS, &ref->count); /* |