diff options
| author | Lee Jones <lee.jones@linaro.org> | 2021-02-04 17:28:54 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-10 09:07:25 +0100 |
| commit | 6510e4a2d04f33e4bfd221760faab23e55d8772b (patch) | |
| tree | 3684392bc6a1b6762ba8c3e8954da5088e3311af /kernel/locking/rtmutex_common.h | |
| parent | 3dee3a42a825734775795f307f03a844d2d31b72 (diff) | |
futex,rt_mutex: Provide futex specific rt_mutex API
From: Peter Zijlstra <peterz@infradead.org>
[ Upstream commit 5293c2efda37775346885c7e924d4ef7018ea60b ]
Part of what makes futex_unlock_pi() intricate is that
rt_mutex_futex_unlock() -> rt_mutex_slowunlock() can drop
rt_mutex::wait_lock.
This means it cannot rely on the atomicy of wait_lock, which would be
preferred in order to not rely on hb->lock so much.
The reason rt_mutex_slowunlock() needs to drop wait_lock is because it can
race with the rt_mutex fastpath, however futexes have their own fast path.
Since futexes already have a bunch of separate rt_mutex accessors, complete
that set and implement a rt_mutex variant without fastpath for them.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: dvhart@infradead.org
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170322104151.702962446@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[Lee: Back-ported to solve a dependency]
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/locking/rtmutex_common.h')
| -rw-r--r-- | kernel/locking/rtmutex_common.h | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index 6f8f68edb700..cdcaccfb7443 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -112,8 +112,12 @@ extern int rt_mutex_wait_proxy_lock(struct rt_mutex *lock, extern bool rt_mutex_cleanup_proxy_lock(struct rt_mutex *lock, struct rt_mutex_waiter *waiter); extern int rt_mutex_timed_futex_lock(struct rt_mutex *l, struct hrtimer_sleeper *to); -extern bool rt_mutex_futex_unlock(struct rt_mutex *lock, - struct wake_q_head *wqh); +extern int rt_mutex_futex_trylock(struct rt_mutex *l); + +extern void rt_mutex_futex_unlock(struct rt_mutex *lock); +extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock, + struct wake_q_head *wqh); + extern void rt_mutex_adjust_prio(struct task_struct *task); #ifdef CONFIG_DEBUG_RT_MUTEXES |