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author | Ingo Molnar <mingo@elte.hu> | 2009-06-11 23:31:52 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-06-11 23:31:52 +0200 |
commit | 0d5959723e1db3fd7323c198a50c16cecf96c7a9 (patch) | |
tree | 802b623fff261ebcbbddadf84af5524398364a18 /kernel/mutex.c | |
parent | 62fdac5913f71f8f200bd2c9bd59a02e9a1498e9 (diff) | |
parent | 512626a04e72aca60effe111fa0333ed0b195d21 (diff) | |
download | talos-op-linux-0d5959723e1db3fd7323c198a50c16cecf96c7a9.tar.gz talos-op-linux-0d5959723e1db3fd7323c198a50c16cecf96c7a9.zip |
Merge branch 'linus' into x86/mce3
Conflicts:
arch/x86/kernel/cpu/mcheck/mce_64.c
arch/x86/kernel/irq.c
Merge reason: Resolve the conflicts above.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/mutex.c')
-rw-r--r-- | kernel/mutex.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/kernel/mutex.c b/kernel/mutex.c index 507cf2b5e9f1..947b3ad551f8 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -89,7 +89,7 @@ __mutex_lock_slowpath(atomic_t *lock_count); * * This function is similar to (but not equivalent to) down(). */ -void inline __sched mutex_lock(struct mutex *lock) +void __sched mutex_lock(struct mutex *lock) { might_sleep(); /* @@ -249,7 +249,9 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, /* didnt get the lock, go to sleep: */ spin_unlock_mutex(&lock->wait_lock, flags); - __schedule(); + preempt_enable_no_resched(); + schedule(); + preempt_disable(); spin_lock_mutex(&lock->wait_lock, flags); } @@ -471,5 +473,28 @@ int __sched mutex_trylock(struct mutex *lock) return ret; } - EXPORT_SYMBOL(mutex_trylock); + +/** + * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0 + * @cnt: the atomic which we are to dec + * @lock: the mutex to return holding if we dec to 0 + * + * return true and hold lock if we dec to 0, return false otherwise + */ +int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) +{ + /* dec if we can't possibly hit 0 */ + if (atomic_add_unless(cnt, -1, 1)) + return 0; + /* we might hit 0, so take the lock */ + mutex_lock(lock); + if (!atomic_dec_and_test(cnt)) { + /* when we actually did the dec, we didn't hit 0 */ + mutex_unlock(lock); + return 0; + } + /* we hit 0, and we hold the lock */ + return 1; +} +EXPORT_SYMBOL(atomic_dec_and_mutex_lock); |