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-rw-r--r--kernel/mutex.c20
1 files changed, 7 insertions, 13 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c
index ff42e975590c..5d79781394a3 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -171,12 +171,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
171 struct thread_info *owner; 171 struct thread_info *owner;
172 172
173 /* 173 /*
174 * If there are pending waiters, join them.
175 */
176 if (!list_empty(&lock->wait_list))
177 break;
178
179 /*
180 * If there's an owner, wait for it to either 174 * If there's an owner, wait for it to either
181 * release the lock or go to sleep. 175 * release the lock or go to sleep.
182 */ 176 */
@@ -184,6 +178,13 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
184 if (owner && !mutex_spin_on_owner(lock, owner)) 178 if (owner && !mutex_spin_on_owner(lock, owner))
185 break; 179 break;
186 180
181 if (atomic_cmpxchg(&lock->count, 1, 0) == 1) {
182 lock_acquired(&lock->dep_map, ip);
183 mutex_set_owner(lock);
184 preempt_enable();
185 return 0;
186 }
187
187 /* 188 /*
188 * When there's no owner, we might have preempted between the 189 * When there's no owner, we might have preempted between the
189 * owner acquiring the lock and setting the owner field. If 190 * owner acquiring the lock and setting the owner field. If
@@ -193,13 +194,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
193 if (!owner && (need_resched() || rt_task(task))) 194 if (!owner && (need_resched() || rt_task(task)))
194 break; 195 break;
195 196
196 if (atomic_cmpxchg(&lock->count, 1, 0) == 1) {
197 lock_acquired(&lock->dep_map, ip);
198 mutex_set_owner(lock);
199 preempt_enable();
200 return 0;
201 }
202
203 /* 197 /*
204 * The cpu_relax() call is a compiler barrier which forces 198 * The cpu_relax() call is a compiler barrier which forces
205 * everything in this loop to be re-loaded. We don't need 199 * everything in this loop to be re-loaded. We don't need