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-rw-r--r--kernel/locking/mutex.c47
1 files changed, 22 insertions, 25 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 49cce442f3ff..59cd6c30421e 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -217,44 +217,41 @@ ww_mutex_set_context_slowpath(struct ww_mutex *lock,
}
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
-static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
-{
- if (lock->owner != owner)
- return false;
-
- /*
- * Ensure we emit the owner->on_cpu, dereference _after_ checking
- * lock->owner still matches owner, if that fails, owner might
- * point to free()d memory, if it still matches, the rcu_read_lock()
- * ensures the memory stays valid.
- */
- barrier();
-
- return owner->on_cpu;
-}
-
/*
* Look out! "owner" is an entirely speculative pointer
* access and not reliable.
*/
static noinline
-int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
+bool mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
{
+ bool ret;
+
rcu_read_lock();
- while (owner_running(lock, owner)) {
- if (need_resched())
+ while (true) {
+ /* Return success when the lock owner changed */
+ if (lock->owner != owner) {
+ ret = true;
break;
+ }
+
+ /*
+ * Ensure we emit the owner->on_cpu, dereference _after_
+ * checking lock->owner still matches owner, if that fails,
+ * owner might point to free()d memory, if it still matches,
+ * the rcu_read_lock() ensures the memory stays valid.
+ */
+ barrier();
+
+ if (!owner->on_cpu || need_resched()) {
+ ret = false;
+ break;
+ }
cpu_relax_lowlatency();
}
rcu_read_unlock();
- /*
- * We break out of the loop above on either need_resched(), when
- * the owner is not running, or when the lock owner changed.
- * Return success only when the lock owner changed.
- */
- return lock->owner != owner;
+ return ret;
}
/*