[patch V4 20/68] locking/rtmutex: Use rt_mutex_wake_q_head

Thomas Gleixner
2021-08-11T12:25:08Z

Prepare for the required state aware handling of waiter wakeups via wake_q
and switch the rtmutex code over to the rtmutex specific wrapper.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V2: Adopt to rename
---
kernel/futex.c | 8 ++++----
kernel/locking/rtmutex.c | 12 ++++++------
kernel/locking/rtmutex_api.c | 19 ++++++++-----------
kernel/locking/rtmutex_common.h | 4 ++--
4 files changed, 20 insertions(+), 23 deletions(-)
---
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1493,11 +1493,11 @@ static void mark_wake_futex(struct wake_
*/
static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_state)
{
- u32 curval, newval;
struct rt_mutex_waiter *top_waiter;
struct task_struct *new_owner;
bool postunlock = false;
- DEFINE_WAKE_Q(wake_q);
+ DEFINE_RT_WAKE_Q(wqh);
+ u32 curval, newval;
int ret = 0;

top_waiter = rt_mutex_top_waiter(&pi_state->pi_mutex);
@@ -1549,14 +1549,14 @@ static int wake_futex_pi(u32 __user *uad
* not fail.
*/
pi_state_update_owner(pi_state, new_owner);
- postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wake_q);
+ postunlock = __rt_mutex_futex_unlock(&pi_state->pi_mutex, &wqh);
}

out_unlock:
raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock);

if (postunlock)
- rt_mutex_postunlock(&wake_q);
+ rt_mutex_postunlock(&wqh);

return ret;
}
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1017,7 +1017,7 @@ static int __sched task_blocks_on_rt_mut
*
* Called with lock->wait_lock held and interrupts disabled.
*/
-static void __sched mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+static void __sched mark_wakeup_next_waiter(struct rt_wake_q_head *wqh,
struct rt_mutex_base *lock)
{
struct rt_mutex_waiter *waiter;
@@ -1054,10 +1054,10 @@ static void __sched mark_wakeup_next_wai
* deboost but before waking our donor task, hence the preempt_disable()
* before unlock.
*
- * Pairs with preempt_enable() in rt_mutex_postunlock();
+ * Pairs with preempt_enable() in rt_mutex_wake_up_q();
*/
preempt_disable();
- wake_q_add(wake_q, waiter->task);
+ rt_mutex_wake_q_add(wqh, waiter);
raw_spin_unlock(&current->pi_lock);
}

@@ -1328,7 +1328,7 @@ static __always_inline int __rt_mutex_tr
*/
static void __sched rt_mutex_slowunlock(struct rt_mutex_base *lock)
{
- DEFINE_WAKE_Q(wake_q);
+ DEFINE_RT_WAKE_Q(wqh);
unsigned long flags;

/* irqsave required to support early boot calls */
@@ -1381,10 +1381,10 @@ static void __sched rt_mutex_slowunlock(
*
* Queue the next waiter for wakeup once we release the wait_lock.
*/
- mark_wakeup_next_waiter(&wake_q, lock);
+ mark_wakeup_next_waiter(&wqh, lock);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

- rt_mutex_postunlock(&wake_q);
+ rt_mutex_wake_up_q(&wqh);
}

static __always_inline void __rt_mutex_unlock(struct rt_mutex_base *lock)
--- a/kernel/locking/rtmutex_api.c
+++ b/kernel/locking/rtmutex_api.c
@@ -137,10 +137,10 @@ int __sched __rt_mutex_futex_trylock(str
* do not use the fast-path, can be simple and will not need to retry.
*
* @lock: The rt_mutex to be unlocked
- * @wake_q: The wake queue head from which to get the next lock waiter
+ * @wqh: The wake queue head from which to get the next lock waiter
*/
bool __sched __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
- struct wake_q_head *wake_q)
+ struct rt_wake_q_head *wqh)
{
lockdep_assert_held(&lock->wait_lock);

@@ -157,23 +157,23 @@ bool __sched __rt_mutex_futex_unlock(str
* avoid inversion prior to the wakeup. preempt_disable()
* therein pairs with rt_mutex_postunlock().
*/
- mark_wakeup_next_waiter(wake_q, lock);
+ mark_wakeup_next_waiter(wqh, lock);

return true; /* call postunlock() */
}

void __sched rt_mutex_futex_unlock(struct rt_mutex_base *lock)
{
- DEFINE_WAKE_Q(wake_q);
+ DEFINE_RT_WAKE_Q(wqh);
unsigned long flags;
bool postunlock;

raw_spin_lock_irqsave(&lock->wait_lock, flags);
- postunlock = __rt_mutex_futex_unlock(lock, &wake_q);
+ postunlock = __rt_mutex_futex_unlock(lock, &wqh);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);

if (postunlock)
- rt_mutex_postunlock(&wake_q);
+ rt_mutex_postunlock(&wqh);
}

/**
@@ -441,12 +441,9 @@ void __sched rt_mutex_adjust_pi(struct t
/*
* Performs the wakeup of the top-waiter and re-enables preemption.
*/
-void __sched rt_mutex_postunlock(struct wake_q_head *wake_q)
+void __sched rt_mutex_postunlock(struct rt_wake_q_head *wqh)
{
- wake_up_q(wake_q);
-
- /* Pairs with preempt_disable() in mark_wakeup_next_waiter() */
- preempt_enable();
+ rt_mutex_wake_up_q(wqh);
}

#ifdef CONFIG_DEBUG_RT_MUTEXES
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -76,9 +76,9 @@ extern int __rt_mutex_futex_trylock(stru

extern void rt_mutex_futex_unlock(struct rt_mutex_base *lock);
extern bool __rt_mutex_futex_unlock(struct rt_mutex_base *lock,
- struct wake_q_head *wake_q);
+ struct rt_wake_q_head *wqh);

-extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
+extern void rt_mutex_postunlock(struct rt_wake_q_head *wqh);

/*
* Must be guarded because this header is included from rcu/tree_plugin.h