diff options
Diffstat (limited to 'kernel/locking/rtmutex.c')
| -rw-r--r-- | kernel/locking/rtmutex.c | 127 |
1 files changed, 77 insertions, 50 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index dd173df9ee5e..1c0cb5c3c6ad 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -937,8 +937,6 @@ takeit: */ rt_mutex_set_owner(lock, task); - rt_mutex_deadlock_account_lock(lock, task); - return 1; } @@ -1286,6 +1284,19 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state, return ret; } +static inline int __rt_mutex_slowtrylock(struct rt_mutex *lock) +{ + int ret = try_to_take_rt_mutex(lock, current, NULL); + + /* + * try_to_take_rt_mutex() sets the lock waiters bit + * unconditionally. Clean this up. + */ + fixup_rt_mutex_waiters(lock); + + return ret; +} + /* * Slow path try-lock function: */ @@ -1307,13 +1318,7 @@ static inline int rt_mutex_slowtrylock(struct rt_mutex *lock) */ raw_spin_lock(&lock->wait_lock); - ret = try_to_take_rt_mutex(lock, current, NULL); - - /* - * try_to_take_rt_mutex() sets the lock waiters bit - * unconditionally. Clean this up. - */ - fixup_rt_mutex_waiters(lock); + ret = __rt_mutex_slowtrylock(lock); raw_spin_unlock(&lock->wait_lock); @@ -1331,8 +1336,6 @@ static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock, debug_rt_mutex_unlock(lock); - rt_mutex_deadlock_account_unlock(current); - /* * We must be careful here if the fast path is enabled. If we * have no waiters queued we cannot set owner to NULL here @@ -1398,11 +1401,10 @@ rt_mutex_fastlock(struct rt_mutex *lock, int state, struct hrtimer_sleeper *timeout, enum rtmutex_chainwalk chwalk)) { - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) { - rt_mutex_deadlock_account_lock(lock, current); + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) return 0; - } else - return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK); + + return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK); } static inline int @@ -1414,21 +1416,19 @@ rt_mutex_timed_fastlock(struct rt_mutex *lock, int state, enum rtmutex_chainwalk chwalk)) { if (chwalk == RT_MUTEX_MIN_CHAINWALK && - likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) { - rt_mutex_deadlock_account_lock(lock, current); + likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) return 0; - } else - return slowfn(lock, state, timeout, chwalk); + + return slowfn(lock, state, timeout, chwalk); } static inline int rt_mutex_fasttrylock(struct rt_mutex *lock, int (*slowfn)(struct rt_mutex *lock)) { - if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) { - rt_mutex_deadlock_account_lock(lock, current); + if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current))) return 1; - } + return slowfn(lock); } @@ -1438,19 +1438,18 @@ rt_mutex_fastunlock(struct rt_mutex *lock, struct wake_q_head *wqh)) { WAKE_Q(wake_q); + bool deboost; - if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) { - rt_mutex_deadlock_account_unlock(current); + if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) + return; - } else { - bool deboost = slowfn(lock, &wake_q); + deboost = slowfn(lock, &wake_q); - wake_up_q(&wake_q); + wake_up_q(&wake_q); - /* Undo pi boosting if necessary: */ - if (deboost) - rt_mutex_adjust_prio(current); - } + /* Undo pi boosting if necessary: */ + if (deboost) + rt_mutex_adjust_prio(current); } /** @@ -1485,15 +1484,28 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); /* * Futex variant with full deadlock detection. + * Futex variants must not use the fast-path, see __rt_mutex_futex_unlock(). */ -int rt_mutex_timed_futex_lock(struct rt_mutex *lock, +int __sched rt_mutex_timed_futex_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout) { might_sleep(); - return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout, - RT_MUTEX_FULL_CHAINWALK, - rt_mutex_slowlock); + return rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, + timeout, RT_MUTEX_FULL_CHAINWALK); +} + +/* + * Futex variant, must not use fastpath. + */ +int __sched rt_mutex_futex_trylock(struct rt_mutex *lock) +{ + return rt_mutex_slowtrylock(lock); +} + +int __sched __rt_mutex_futex_trylock(struct rt_mutex *lock) +{ + return __rt_mutex_slowtrylock(lock); } /** @@ -1552,20 +1564,38 @@ void __sched rt_mutex_unlock(struct rt_mutex *lock) EXPORT_SYMBOL_GPL(rt_mutex_unlock); /** - * rt_mutex_futex_unlock - Futex variant of rt_mutex_unlock - * @lock: the rt_mutex to be unlocked - * - * Returns: true/false indicating whether priority adjustment is - * required or not. + * Futex variant, that since futex variants do not use the fast-path, can be + * simple and will not need to retry. */ -bool __sched rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wqh) +bool __sched __rt_mutex_futex_unlock(struct rt_mutex *lock, + struct wake_q_head *wake_q) { - if (likely(rt_mutex_cmpxchg_release(lock, current, NULL))) { - rt_mutex_deadlock_account_unlock(current); - return false; + lockdep_assert_held(&lock->wait_lock); + + debug_rt_mutex_unlock(lock); + + if (!rt_mutex_has_waiters(lock)) { + lock->owner = NULL; + return false; /* done */ + } + + mark_wakeup_next_waiter(wake_q, lock); + return true; /* deboost and wakeups */ +} + +void __sched rt_mutex_futex_unlock(struct rt_mutex *lock) +{ + WAKE_Q(wake_q); + bool deboost; + + raw_spin_lock_irq(&lock->wait_lock); + deboost = __rt_mutex_futex_unlock(lock, &wake_q); + raw_spin_unlock_irq(&lock->wait_lock); + + if (deboost) { + wake_up_q(&wake_q); + rt_mutex_adjust_prio(current); } - return rt_mutex_slowunlock(lock, wqh); } /** @@ -1622,7 +1652,6 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock, __rt_mutex_init(lock, NULL); debug_rt_mutex_proxy_lock(lock, proxy_owner); rt_mutex_set_owner(lock, proxy_owner); - rt_mutex_deadlock_account_lock(lock, proxy_owner); } /** @@ -1633,12 +1662,10 @@ void rt_mutex_init_proxy_locked(struct rt_mutex *lock, * No locking. Caller has to do serializing itself * Special API call for PI-futex support */ -void rt_mutex_proxy_unlock(struct rt_mutex *lock, - struct task_struct *proxy_owner) +void rt_mutex_proxy_unlock(struct rt_mutex *lock) { debug_rt_mutex_proxy_unlock(lock); rt_mutex_set_owner(lock, NULL); - rt_mutex_deadlock_account_unlock(proxy_owner); } /** |