[PATCH v2 1/4] jump_label: Move cpu hotplug locking

From: Marc Zyngier
Date: Tue Aug 01 2017 - 04:04:13 EST


As we're about to rework the locking, let's move the taking and
release of the CPU hotplug lock to locations that will make its
reworking completely obvious.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
kernel/jump_label.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index d11c506a6ac3..f11b10091100 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -105,6 +105,7 @@ void static_key_slow_inc(struct static_key *key)
{
int v, v1;

+ cpus_read_lock();
STATIC_KEY_CHECK_USE();

/*
@@ -121,11 +122,12 @@ void static_key_slow_inc(struct static_key *key)
*/
for (v = atomic_read(&key->enabled); v > 0; v = v1) {
v1 = atomic_cmpxchg(&key->enabled, v, v + 1);
- if (likely(v1 == v))
+ if (likely(v1 == v)) {
+ cpus_read_unlock();
return;
+ }
}

- cpus_read_lock();
jump_label_lock();
if (atomic_read(&key->enabled) == 0) {
atomic_set(&key->enabled, -1);
--
2.11.0