diff options
| author | Alex Van Brunt <avanbrunt@nvidia.com> | 2014-05-16 12:37:06 -0700 |
|---|---|---|
| committer | Mandar Padmawar <mpadmawar@nvidia.com> | 2014-05-23 01:57:53 -0700 |
| commit | 1937ef6f9ce114ad8a9cac6a06e3dce8a1affae2 (patch) | |
| tree | 32e8ca16ec87c1b5148ca53bd55e233a18c19ab6 | |
| parent | 82f35296c448f4701e4cfce7b37114a9915ea2a2 (diff) | |
mutex: save power with better cpu_relax
Use cpu_relaxed_read and cpu_read_relax to allow more architectures to be able
to "relax" instead of busy spinning.
Bug 1440421
Change-Id: I48e36d7b3c953fe43ebb23ea814de7738c91e394
Signed-off-by: Alex Van Brunt <avanbrunt@nvidia.com>
Reviewed-on: http://git-master/r/412712
Reviewed-by: Sumit Singh <sumsingh@nvidia.com>
GVS: Gerrit_Virtual_Submit
| -rw-r--r-- | kernel/mutex.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c index ad53a664f113..ee2254231661 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -137,8 +137,8 @@ void mspin_lock(struct mspin_node **lock, struct mspin_node *node) ACCESS_ONCE(prev->next) = node; smp_wmb(); /* Wait until the lock holder passes the lock down */ - while (!ACCESS_ONCE(node->locked)) - arch_mutex_cpu_relax(); + while (!cpu_relaxed_read(&(node->locked))) + cpu_read_relax(); } static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node) @@ -152,8 +152,8 @@ static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node) if (cmpxchg(lock, node, NULL) == node) return; /* Wait until the next pointer is set */ - while (!(next = ACCESS_ONCE(node->next))) - arch_mutex_cpu_relax(); + while (!(next = cpu_relaxed_read_long(&(node->next)))) + cpu_read_relax(); } ACCESS_ONCE(next->locked) = 1; smp_wmb(); |