From e3e12f52b214121840b44c91de5b3e5af5d3eb84 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 06 Nov 2023 03:04:41 +0000
Subject: [PATCH] rk3568 rt init
---
kernel/kernel/locking/rtmutex.c | 962 ++++++++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 856 insertions(+), 106 deletions(-)
diff --git a/kernel/kernel/locking/rtmutex.c b/kernel/kernel/locking/rtmutex.c
index a5ec4f6..fe5153f 100644
--- a/kernel/kernel/locking/rtmutex.c
+++ b/kernel/kernel/locking/rtmutex.c
@@ -7,6 +7,11 @@
* Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
* Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
* Copyright (C) 2006 Esben Nielsen
+ * Adaptive Spinlocks:
+ * Copyright (C) 2008 Novell, Inc., Gregory Haskins, Sven Dietrich,
+ * and Peter Morreale,
+ * Adaptive Spinlocks simplification:
+ * Copyright (C) 2008 Red Hat, Inc., Steven Rostedt <srostedt@redhat.com>
*
* See Documentation/locking/rt-mutex-design.txt for details.
*/
@@ -18,6 +23,8 @@
#include <linux/sched/wake_q.h>
#include <linux/sched/debug.h>
#include <linux/timer.h>
+#include <linux/ww_mutex.h>
+#include <linux/blkdev.h>
#include "rtmutex_common.h"
@@ -135,6 +142,12 @@
WRITE_ONCE(*p, owner & ~RT_MUTEX_HAS_WAITERS);
}
+static int rt_mutex_real_waiter(struct rt_mutex_waiter *waiter)
+{
+ return waiter && waiter != PI_WAKEUP_INPROGRESS &&
+ waiter != PI_REQUEUE_INPROGRESS;
+}
+
/*
* We can speed up the acquire/release, if there's no debugging state to be
* set up.
@@ -228,7 +241,7 @@
* Only use with rt_mutex_waiter_{less,equal}()
*/
#define task_to_waiter(p) \
- &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline }
+ &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline, .task = (p) }
static inline int
rt_mutex_waiter_less(struct rt_mutex_waiter *left,
@@ -266,6 +279,27 @@
return left->deadline == right->deadline;
return 1;
+}
+
+#define STEAL_NORMAL 0
+#define STEAL_LATERAL 1
+
+static inline int
+rt_mutex_steal(struct rt_mutex *lock, struct rt_mutex_waiter *waiter, int mode)
+{
+ struct rt_mutex_waiter *top_waiter = rt_mutex_top_waiter(lock);
+
+ if (waiter == top_waiter || rt_mutex_waiter_less(waiter, top_waiter))
+ return 1;
+
+ /*
+ * Note that RT tasks are excluded from lateral-steals
+ * to prevent the introduction of an unbounded latency.
+ */
+ if (mode == STEAL_NORMAL || rt_task(waiter->task))
+ return 0;
+
+ return rt_mutex_waiter_equal(waiter, top_waiter);
}
static void
@@ -372,6 +406,14 @@
return debug_rt_mutex_detect_deadlock(waiter, chwalk);
}
+static void rt_mutex_wake_waiter(struct rt_mutex_waiter *waiter)
+{
+ if (waiter->savestate)
+ wake_up_lock_sleeper(waiter->task);
+ else
+ wake_up_process(waiter->task);
+}
+
/*
* Max number of times we'll walk the boosting chain:
*/
@@ -379,7 +421,8 @@
static inline struct rt_mutex *task_blocked_on_lock(struct task_struct *p)
{
- return p->pi_blocked_on ? p->pi_blocked_on->lock : NULL;
+ return rt_mutex_real_waiter(p->pi_blocked_on) ?
+ p->pi_blocked_on->lock : NULL;
}
/*
@@ -515,7 +558,7 @@
* reached or the state of the chain has changed while we
* dropped the locks.
*/
- if (!waiter)
+ if (!rt_mutex_real_waiter(waiter))
goto out_unlock_pi;
/*
@@ -696,13 +739,16 @@
* follow here. This is the end of the chain we are walking.
*/
if (!rt_mutex_owner(lock)) {
+ struct rt_mutex_waiter *lock_top_waiter;
+
/*
* If the requeue [7] above changed the top waiter,
* then we need to wake the new top waiter up to try
* to get the lock.
*/
- if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
+ lock_top_waiter = rt_mutex_top_waiter(lock);
+ if (prerequeue_top_waiter != lock_top_waiter)
+ rt_mutex_wake_waiter(lock_top_waiter);
raw_spin_unlock_irq(&lock->wait_lock);
return 0;
}
@@ -804,9 +850,11 @@
* @task: The task which wants to acquire the lock
* @waiter: The waiter that is queued to the lock's wait tree if the
* callsite called task_blocked_on_lock(), otherwise NULL
+ * @mode: Lock steal mode (STEAL_NORMAL, STEAL_LATERAL)
*/
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
+static int __try_to_take_rt_mutex(struct rt_mutex *lock,
+ struct task_struct *task,
+ struct rt_mutex_waiter *waiter, int mode)
{
lockdep_assert_held(&lock->wait_lock);
@@ -842,12 +890,11 @@
*/
if (waiter) {
/*
- * If waiter is not the highest priority waiter of
- * @lock, give up.
+ * If waiter is not the highest priority waiter of @lock,
+ * or its peer when lateral steal is allowed, give up.
*/
- if (waiter != rt_mutex_top_waiter(lock))
+ if (!rt_mutex_steal(lock, waiter, mode))
return 0;
-
/*
* We can acquire the lock. Remove the waiter from the
* lock waiters tree.
@@ -865,14 +912,12 @@
*/
if (rt_mutex_has_waiters(lock)) {
/*
- * If @task->prio is greater than or equal to
- * the top waiter priority (kernel view),
- * @task lost.
+ * If @task->prio is greater than the top waiter
+ * priority (kernel view), or equal to it when a
+ * lateral steal is forbidden, @task lost.
*/
- if (!rt_mutex_waiter_less(task_to_waiter(task),
- rt_mutex_top_waiter(lock)))
+ if (!rt_mutex_steal(lock, task_to_waiter(task), mode))
return 0;
-
/*
* The current top waiter stays enqueued. We
* don't have to change anything in the lock
@@ -919,6 +964,344 @@
return 1;
}
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * preemptible spin_lock functions:
+ */
+static inline void rt_spin_lock_fastlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ might_sleep_no_state_check();
+
+ if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
+ return;
+ else
+ slowfn(lock);
+}
+
+static inline void rt_spin_lock_fastunlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
+ return;
+ else
+ slowfn(lock);
+}
+#ifdef CONFIG_SMP
+/*
+ * Note that owner is a speculative pointer and dereferencing relies
+ * on rcu_read_lock() and the check against the lock owner.
+ */
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *owner)
+{
+ int res = 0;
+
+ rcu_read_lock();
+ for (;;) {
+ if (owner != rt_mutex_owner(lock))
+ break;
+ /*
+ * Ensure that owner->on_cpu is dereferenced _after_
+ * checking the above to be valid.
+ */
+ barrier();
+ if (!owner->on_cpu) {
+ res = 1;
+ break;
+ }
+ cpu_relax();
+ }
+ rcu_read_unlock();
+ return res;
+}
+#else
+static int adaptive_wait(struct rt_mutex *lock,
+ struct task_struct *orig_owner)
+{
+ return 1;
+}
+#endif
+
+static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
+ enum rtmutex_chainwalk chwalk);
+/*
+ * Slow path lock function spin_lock style: this variant is very
+ * careful not to miss any non-lock wakeups.
+ *
+ * We store the current state under p->pi_lock in p->saved_state and
+ * the try_to_wake_up() code handles this accordingly.
+ */
+void __sched rt_spin_lock_slowlock_locked(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ unsigned long flags)
+{
+ struct task_struct *lock_owner, *self = current;
+ struct rt_mutex_waiter *top_waiter;
+ int ret;
+
+ if (__try_to_take_rt_mutex(lock, self, NULL, STEAL_LATERAL))
+ return;
+
+ BUG_ON(rt_mutex_owner(lock) == self);
+
+ /*
+ * We save whatever state the task is in and we'll restore it
+ * after acquiring the lock taking real wakeups into account
+ * as well. We are serialized via pi_lock against wakeups. See
+ * try_to_wake_up().
+ */
+ raw_spin_lock(&self->pi_lock);
+ self->saved_state = self->state;
+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+ raw_spin_unlock(&self->pi_lock);
+
+ ret = task_blocks_on_rt_mutex(lock, waiter, self, RT_MUTEX_MIN_CHAINWALK);
+ BUG_ON(ret);
+
+ for (;;) {
+ /* Try to acquire the lock again. */
+ if (__try_to_take_rt_mutex(lock, self, waiter, STEAL_LATERAL))
+ break;
+
+ top_waiter = rt_mutex_top_waiter(lock);
+ lock_owner = rt_mutex_owner(lock);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+ debug_rt_mutex_print_deadlock(waiter);
+
+ if (top_waiter != waiter || adaptive_wait(lock, lock_owner))
+ schedule();
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+
+ raw_spin_lock(&self->pi_lock);
+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+ raw_spin_unlock(&self->pi_lock);
+ }
+
+ /*
+ * Restore the task state to current->saved_state. We set it
+ * to the original state above and the try_to_wake_up() code
+ * has possibly updated it when a real (non-rtmutex) wakeup
+ * happened while we were blocked. Clear saved_state so
+ * try_to_wakeup() does not get confused.
+ */
+ raw_spin_lock(&self->pi_lock);
+ __set_current_state_no_track(self->saved_state);
+ self->saved_state = TASK_RUNNING;
+ raw_spin_unlock(&self->pi_lock);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up:
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ BUG_ON(rt_mutex_has_waiters(lock) && waiter == rt_mutex_top_waiter(lock));
+ BUG_ON(!RB_EMPTY_NODE(&waiter->tree_entry));
+}
+
+static void noinline __sched rt_spin_lock_slowlock(struct rt_mutex *lock)
+{
+ struct rt_mutex_waiter waiter;
+ unsigned long flags;
+
+ rt_mutex_init_waiter(&waiter, true);
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+ rt_spin_lock_slowlock_locked(lock, &waiter, flags);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+ debug_rt_mutex_free_waiter(&waiter);
+}
+
+static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wq_sleeper);
+/*
+ * Slow path to release a rt_mutex spin_lock style
+ */
+void __sched rt_spin_lock_slowunlock(struct rt_mutex *lock)
+{
+ unsigned long flags;
+ DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
+ bool postunlock;
+
+ raw_spin_lock_irqsave(&lock->wait_lock, flags);
+ postunlock = __rt_mutex_unlock_common(lock, &wake_q, &wake_sleeper_q);
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+ if (postunlock)
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+}
+
+void __lockfunc rt_spin_lock(spinlock_t *lock)
+{
+ sleeping_lock_inc();
+ rcu_read_lock();
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(rt_spin_lock);
+
+void __lockfunc __rt_spin_lock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastlock(lock, rt_spin_lock_slowlock);
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+void __lockfunc rt_spin_lock_nested(spinlock_t *lock, int subclass)
+{
+ sleeping_lock_inc();
+ rcu_read_lock();
+ migrate_disable();
+ spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ rt_spin_lock_fastlock(&lock->lock, rt_spin_lock_slowlock);
+}
+EXPORT_SYMBOL(rt_spin_lock_nested);
+#endif
+
+void __lockfunc rt_spin_unlock(spinlock_t *lock)
+{
+ /* NOTE: we always pass in '1' for nested, for simplicity */
+ spin_release(&lock->dep_map, 1, _RET_IP_);
+ rt_spin_lock_fastunlock(&lock->lock, rt_spin_lock_slowunlock);
+ migrate_enable();
+ rcu_read_unlock();
+ sleeping_lock_dec();
+}
+EXPORT_SYMBOL(rt_spin_unlock);
+
+void __lockfunc __rt_spin_unlock(struct rt_mutex *lock)
+{
+ rt_spin_lock_fastunlock(lock, rt_spin_lock_slowunlock);
+}
+EXPORT_SYMBOL(__rt_spin_unlock);
+
+/*
+ * Wait for the lock to get unlocked: instead of polling for an unlock
+ * (like raw spinlocks do), we lock and unlock, to force the kernel to
+ * schedule if there's contention:
+ */
+void __lockfunc rt_spin_unlock_wait(spinlock_t *lock)
+{
+ spin_lock(lock);
+ spin_unlock(lock);
+}
+EXPORT_SYMBOL(rt_spin_unlock_wait);
+
+int __lockfunc rt_spin_trylock(spinlock_t *lock)
+{
+ int ret;
+
+ sleeping_lock_inc();
+ migrate_disable();
+ ret = __rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ rcu_read_lock();
+ } else {
+ migrate_enable();
+ sleeping_lock_dec();
+ }
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock);
+
+int __lockfunc rt_spin_trylock_bh(spinlock_t *lock)
+{
+ int ret;
+
+ local_bh_disable();
+ ret = __rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ sleeping_lock_inc();
+ rcu_read_lock();
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ } else
+ local_bh_enable();
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_bh);
+
+int __lockfunc rt_spin_trylock_irqsave(spinlock_t *lock, unsigned long *flags)
+{
+ int ret;
+
+ *flags = 0;
+ ret = __rt_mutex_trylock(&lock->lock);
+ if (ret) {
+ sleeping_lock_inc();
+ rcu_read_lock();
+ migrate_disable();
+ spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(rt_spin_trylock_irqsave);
+
+void
+__rt_spin_lock_init(spinlock_t *lock, const char *name, struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
+}
+EXPORT_SYMBOL(__rt_spin_lock_init);
+
+#endif /* PREEMPT_RT_FULL */
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct ww_acquire_ctx *hold_ctx = READ_ONCE(ww->ctx);
+
+ if (!hold_ctx)
+ return 0;
+
+ if (unlikely(ctx == hold_ctx))
+ return -EALREADY;
+
+ if (ctx->stamp - hold_ctx->stamp <= LONG_MAX &&
+ (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(ctx->contending_lock);
+ ctx->contending_lock = ww;
+#endif
+ return -EDEADLK;
+ }
+
+ return 0;
+}
+#else
+ static inline int __sched
+__mutex_lock_check_stamp(struct rt_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ BUG();
+ return 0;
+}
+
+#endif
+
+static inline int
+try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter)
+{
+ return __try_to_take_rt_mutex(lock, task, waiter, STEAL_NORMAL);
+}
+
/*
* Task blocks on lock.
*
@@ -951,6 +1334,22 @@
return -EDEADLK;
raw_spin_lock(&task->pi_lock);
+ /*
+ * In the case of futex requeue PI, this will be a proxy
+ * lock. The task will wake unaware that it is enqueueed on
+ * this lock. Avoid blocking on two locks and corrupting
+ * pi_blocked_on via the PI_WAKEUP_INPROGRESS
+ * flag. futex_wait_requeue_pi() sets this when it wakes up
+ * before requeue (due to a signal or timeout). Do not enqueue
+ * the task if PI_WAKEUP_INPROGRESS is set.
+ */
+ if (task != current && task->pi_blocked_on == PI_WAKEUP_INPROGRESS) {
+ raw_spin_unlock(&task->pi_lock);
+ return -EAGAIN;
+ }
+
+ BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on));
+
waiter->task = task;
waiter->lock = lock;
waiter->prio = task->prio;
@@ -974,7 +1373,7 @@
rt_mutex_enqueue_pi(owner, waiter);
rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
chain_walk = 1;
} else if (rt_mutex_cond_detect_deadlock(waiter, chwalk)) {
chain_walk = 1;
@@ -1016,6 +1415,7 @@
* Called with lock->wait_lock held and interrupts disabled.
*/
static void mark_wakeup_next_waiter(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q,
struct rt_mutex *lock)
{
struct rt_mutex_waiter *waiter;
@@ -1055,7 +1455,10 @@
* Pairs with preempt_enable() in rt_mutex_postunlock();
*/
preempt_disable();
- wake_q_add(wake_q, waiter->task);
+ if (waiter->savestate)
+ wake_q_add_sleeper(wake_sleeper_q, waiter->task);
+ else
+ wake_q_add(wake_q, waiter->task);
raw_spin_unlock(¤t->pi_lock);
}
@@ -1070,7 +1473,7 @@
{
bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
- struct rt_mutex *next_lock;
+ struct rt_mutex *next_lock = NULL;
lockdep_assert_held(&lock->wait_lock);
@@ -1096,7 +1499,8 @@
rt_mutex_adjust_prio(owner);
/* Store the lock on which owner is blocked or NULL */
- next_lock = task_blocked_on_lock(owner);
+ if (rt_mutex_real_waiter(owner->pi_blocked_on))
+ next_lock = task_blocked_on_lock(owner);
raw_spin_unlock(&owner->pi_lock);
@@ -1132,26 +1536,28 @@
raw_spin_lock_irqsave(&task->pi_lock, flags);
waiter = task->pi_blocked_on;
- if (!waiter || rt_mutex_waiter_equal(waiter, task_to_waiter(task))) {
+ if (!rt_mutex_real_waiter(waiter) ||
+ rt_mutex_waiter_equal(waiter, task_to_waiter(task))) {
raw_spin_unlock_irqrestore(&task->pi_lock, flags);
return;
}
next_lock = waiter->lock;
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
/* gets dropped in rt_mutex_adjust_prio_chain()! */
get_task_struct(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
rt_mutex_adjust_prio_chain(task, RT_MUTEX_MIN_CHAINWALK, NULL,
next_lock, NULL, task);
}
-void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter, bool savestate)
{
debug_rt_mutex_init_waiter(waiter);
RB_CLEAR_NODE(&waiter->pi_tree_entry);
RB_CLEAR_NODE(&waiter->tree_entry);
waiter->task = NULL;
+ waiter->savestate = savestate;
}
/**
@@ -1167,7 +1573,8 @@
static int __sched
__rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
+ struct rt_mutex_waiter *waiter,
+ struct ww_acquire_ctx *ww_ctx)
{
int ret = 0;
@@ -1176,16 +1583,17 @@
if (try_to_take_rt_mutex(lock, current, waiter))
break;
- /*
- * TASK_INTERRUPTIBLE checks for signals and
- * timeout. Ignored otherwise.
- */
- if (likely(state == TASK_INTERRUPTIBLE)) {
- /* Signal pending? */
- if (signal_pending(current))
- ret = -EINTR;
- if (timeout && !timeout->task)
- ret = -ETIMEDOUT;
+ if (timeout && !timeout->task) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+ if (signal_pending_state(state, current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ if (ww_ctx && ww_ctx->acquired > 0) {
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
if (ret)
break;
}
@@ -1224,19 +1632,157 @@
}
}
+static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
+ struct ww_acquire_ctx *ww_ctx)
+{
+#ifdef CONFIG_DEBUG_MUTEXES
+ /*
+ * If this WARN_ON triggers, you used ww_mutex_lock to acquire,
+ * but released with a normal mutex_unlock in this call.
+ *
+ * This should never happen, always use ww_mutex_unlock.
+ */
+ DEBUG_LOCKS_WARN_ON(ww->ctx);
+
+ /*
+ * Not quite done after calling ww_acquire_done() ?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->done_acquire);
+
+ if (ww_ctx->contending_lock) {
+ /*
+ * After -EDEADLK you tried to
+ * acquire a different ww_mutex? Bad!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->contending_lock != ww);
+
+ /*
+ * You called ww_mutex_lock after receiving -EDEADLK,
+ * but 'forgot' to unlock everything else first?
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->acquired > 0);
+ ww_ctx->contending_lock = NULL;
+ }
+
+ /*
+ * Naughty, using a different class will lead to undefined behavior!
+ */
+ DEBUG_LOCKS_WARN_ON(ww_ctx->ww_class != ww->ww_class);
+#endif
+ ww_ctx->acquired++;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ struct ww_mutex *ww = container_of(lock, struct ww_mutex, base.lock);
+ struct rt_mutex_waiter *waiter, *n;
+
+ /*
+ * This branch gets optimized out for the common case,
+ * and is only important for ww_mutex_lock.
+ */
+ ww_mutex_lock_acquired(ww, ww_ctx);
+ ww->ctx = ww_ctx;
+
+ /*
+ * Give any possible sleeping processes the chance to wake up,
+ * so they can recheck if they have to back off.
+ */
+ rbtree_postorder_for_each_entry_safe(waiter, n, &lock->waiters.rb_root,
+ tree_entry) {
+ /* XXX debug rt mutex waiter wakeup */
+
+ BUG_ON(waiter->lock != lock);
+ rt_mutex_wake_waiter(waiter);
+ }
+}
+
+#else
+
+static void ww_mutex_account_lock(struct rt_mutex *lock,
+ struct ww_acquire_ctx *ww_ctx)
+{
+ BUG();
+}
+#endif
+
+int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
+ struct rt_mutex_waiter *waiter)
+{
+ int ret;
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (ww_ctx) {
+ struct ww_mutex *ww;
+
+ ww = container_of(lock, struct ww_mutex, base.lock);
+ if (unlikely(ww_ctx == READ_ONCE(ww->ctx)))
+ return -EALREADY;
+ }
+#endif
+
+ /* Try to acquire the lock again: */
+ if (try_to_take_rt_mutex(lock, current, NULL)) {
+ if (ww_ctx)
+ ww_mutex_account_lock(lock, ww_ctx);
+ return 0;
+ }
+
+ set_current_state(state);
+
+ /* Setup the timer, when timeout != NULL */
+ if (unlikely(timeout))
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+
+ ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk);
+
+ if (likely(!ret)) {
+ /* sleep on the mutex */
+ ret = __rt_mutex_slowlock(lock, state, timeout, waiter,
+ ww_ctx);
+ } else if (ww_ctx) {
+ /* ww_mutex received EDEADLK, let it become EALREADY */
+ ret = __mutex_lock_check_stamp(lock, ww_ctx);
+ BUG_ON(!ret);
+ }
+
+ if (unlikely(ret)) {
+ __set_current_state(TASK_RUNNING);
+ remove_waiter(lock, waiter);
+ /* ww_mutex wants to report EDEADLK/EALREADY, let it */
+ if (!ww_ctx)
+ rt_mutex_handle_deadlock(ret, chwalk, waiter);
+ } else if (ww_ctx) {
+ ww_mutex_account_lock(lock, ww_ctx);
+ }
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
+ return ret;
+}
+
/*
* Slow path lock function:
*/
static int __sched
rt_mutex_slowlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk)
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx)
{
struct rt_mutex_waiter waiter;
unsigned long flags;
int ret = 0;
- rt_mutex_init_waiter(&waiter);
+ rt_mutex_init_waiter(&waiter, false);
/*
* Technically we could use raw_spin_[un]lock_irq() here, but this can
@@ -1248,35 +1794,8 @@
*/
raw_spin_lock_irqsave(&lock->wait_lock, flags);
- /* Try to acquire the lock again: */
- if (try_to_take_rt_mutex(lock, current, NULL)) {
- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
- return 0;
- }
-
- set_current_state(state);
-
- /* Setup the timer, when timeout != NULL */
- if (unlikely(timeout))
- hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
-
- ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
-
- if (likely(!ret))
- /* sleep on the mutex */
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
-
- if (unlikely(ret)) {
- __set_current_state(TASK_RUNNING);
- remove_waiter(lock, &waiter);
- rt_mutex_handle_deadlock(ret, chwalk, &waiter);
- }
-
- /*
- * try_to_take_rt_mutex() sets the waiter bit
- * unconditionally. We might have to fix that up.
- */
- fixup_rt_mutex_waiters(lock);
+ ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, ww_ctx,
+ &waiter);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
@@ -1337,7 +1856,8 @@
* Return whether the current task needs to call rt_mutex_postunlock().
*/
static bool __sched rt_mutex_slowunlock(struct rt_mutex *lock,
- struct wake_q_head *wake_q)
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q)
{
unsigned long flags;
@@ -1391,7 +1911,7 @@
*
* Queue the next waiter for wakeup once we release the wait_lock.
*/
- mark_wakeup_next_waiter(wake_q, lock);
+ mark_wakeup_next_waiter(wake_q, wake_sleeper_q, lock);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
return true; /* call rt_mutex_postunlock() */
@@ -1405,29 +1925,45 @@
*/
static inline int
rt_mutex_fastlock(struct rt_mutex *lock, int state,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
- return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK);
+ /*
+ * If rt_mutex blocks, the function sched_submit_work will not call
+ * blk_schedule_flush_plug (because tsk_is_pi_blocked would be true).
+ * We must call blk_schedule_flush_plug here, if we don't call it,
+ * a deadlock in I/O may happen.
+ */
+ if (unlikely(blk_needs_flush_plug(current)))
+ blk_schedule_flush_plug(current);
+
+ return slowfn(lock, state, NULL, RT_MUTEX_MIN_CHAINWALK, ww_ctx);
}
static inline int
rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx,
int (*slowfn)(struct rt_mutex *lock, int state,
struct hrtimer_sleeper *timeout,
- enum rtmutex_chainwalk chwalk))
+ enum rtmutex_chainwalk chwalk,
+ struct ww_acquire_ctx *ww_ctx))
{
if (chwalk == RT_MUTEX_MIN_CHAINWALK &&
likely(rt_mutex_cmpxchg_acquire(lock, NULL, current)))
return 0;
- return slowfn(lock, state, timeout, chwalk);
+ if (unlikely(blk_needs_flush_plug(current)))
+ blk_schedule_flush_plug(current);
+
+ return slowfn(lock, state, timeout, chwalk, ww_ctx);
}
static inline int
@@ -1443,9 +1979,11 @@
/*
* Performs the wakeup of the the top-waiter and re-enables preemption.
*/
-void rt_mutex_postunlock(struct wake_q_head *wake_q)
+void rt_mutex_postunlock(struct wake_q_head *wake_q,
+ struct wake_q_head *wake_sleeper_q)
{
wake_up_q(wake_q);
+ wake_up_q_sleeper(wake_sleeper_q);
/* Pairs with preempt_disable() in rt_mutex_slowunlock() */
preempt_enable();
@@ -1454,23 +1992,46 @@
static inline void
rt_mutex_fastunlock(struct rt_mutex *lock,
bool (*slowfn)(struct rt_mutex *lock,
- struct wake_q_head *wqh))
+ struct wake_q_head *wqh,
+ struct wake_q_head *wq_sleeper))
{
DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
if (likely(rt_mutex_cmpxchg_release(lock, current, NULL)))
return;
- if (slowfn(lock, &wake_q))
- rt_mutex_postunlock(&wake_q);
+ if (slowfn(lock, &wake_q, &wake_sleeper_q))
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
+}
+
+int __sched __rt_mutex_lock_state(struct rt_mutex *lock, int state)
+{
+ might_sleep();
+ return rt_mutex_fastlock(lock, state, NULL, rt_mutex_slowlock);
+}
+
+/**
+ * rt_mutex_lock_state - lock a rt_mutex with a given state
+ *
+ * @lock: The rt_mutex to be locked
+ * @state: The state to set when blocking on the rt_mutex
+ */
+static inline int __sched rt_mutex_lock_state(struct rt_mutex *lock,
+ unsigned int subclass, int state)
+{
+ int ret;
+
+ mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
+ ret = __rt_mutex_lock_state(lock, state);
+ if (ret)
+ mutex_release(&lock->dep_map, 1, _RET_IP_);
+ return ret;
}
static inline void __rt_mutex_lock(struct rt_mutex *lock, unsigned int subclass)
{
- might_sleep();
-
- mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock);
+ rt_mutex_lock_state(lock, subclass, TASK_UNINTERRUPTIBLE);
}
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -1511,16 +2072,7 @@
*/
int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock)
{
- int ret;
-
- might_sleep();
-
- mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
- ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock);
- if (ret)
- mutex_release(&lock->dep_map, 1, _RET_IP_);
-
- return ret;
+ return rt_mutex_lock_state(lock, 0, TASK_INTERRUPTIBLE);
}
EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
@@ -1536,6 +2088,22 @@
{
return __rt_mutex_slowtrylock(lock);
}
+
+/**
+ * rt_mutex_lock_killable - lock a rt_mutex killable
+ *
+ * @lock: the rt_mutex to be locked
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ */
+int __sched rt_mutex_lock_killable(struct rt_mutex *lock)
+{
+ return rt_mutex_lock_state(lock, 0, TASK_KILLABLE);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_killable);
/**
* rt_mutex_timed_lock - lock a rt_mutex interruptible
@@ -1560,6 +2128,7 @@
mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_);
ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
RT_MUTEX_MIN_CHAINWALK,
+ NULL,
rt_mutex_slowlock);
if (ret)
mutex_release(&lock->dep_map, 1, _RET_IP_);
@@ -1567,6 +2136,18 @@
return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
+
+int __sched __rt_mutex_trylock(struct rt_mutex *lock)
+{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (WARN_ON_ONCE(in_irq() || in_nmi()))
+#else
+ if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
+#endif
+ return 0;
+
+ return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+}
/**
* rt_mutex_trylock - try to lock a rt_mutex
@@ -1583,16 +2164,18 @@
{
int ret;
- if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq()))
- return 0;
-
- ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+ ret = __rt_mutex_trylock(lock);
if (ret)
mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_);
return ret;
}
EXPORT_SYMBOL_GPL(rt_mutex_trylock);
+
+void __sched __rt_mutex_unlock(struct rt_mutex *lock)
+{
+ rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+}
/**
* rt_mutex_unlock - unlock a rt_mutex
@@ -1602,16 +2185,13 @@
void __sched rt_mutex_unlock(struct rt_mutex *lock)
{
mutex_release(&lock->dep_map, 1, _RET_IP_);
- rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+ __rt_mutex_unlock(lock);
}
EXPORT_SYMBOL_GPL(rt_mutex_unlock);
-/**
- * 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 *wake_q)
+static bool __sched __rt_mutex_unlock_common(struct rt_mutex *lock,
+ struct wake_q_head *wake_q,
+ struct wake_q_head *wq_sleeper)
{
lockdep_assert_held(&lock->wait_lock);
@@ -1628,23 +2208,35 @@
* 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(wake_q, wq_sleeper, lock);
return true; /* call postunlock() */
+}
+
+/**
+ * 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 *wake_q,
+ struct wake_q_head *wq_sleeper)
+{
+ return __rt_mutex_unlock_common(lock, wake_q, wq_sleeper);
}
void __sched rt_mutex_futex_unlock(struct rt_mutex *lock)
{
DEFINE_WAKE_Q(wake_q);
+ DEFINE_WAKE_Q(wake_sleeper_q);
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, &wake_q, &wake_sleeper_q);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
if (postunlock)
- rt_mutex_postunlock(&wake_q);
+ rt_mutex_postunlock(&wake_q, &wake_sleeper_q);
}
/**
@@ -1683,7 +2275,7 @@
if (name && key)
debug_rt_mutex_init(lock, name, key);
}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
+EXPORT_SYMBOL(__rt_mutex_init);
/**
* rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
@@ -1703,6 +2295,14 @@
struct task_struct *proxy_owner)
{
__rt_mutex_init(lock, NULL, NULL);
+#ifdef CONFIG_DEBUG_SPINLOCK
+ /*
+ * get another key class for the wait_lock. LOCK_PI and UNLOCK_PI is
+ * holding the ->wait_lock of the proxy_lock while unlocking a sleeping
+ * lock.
+ */
+ raw_spin_lock_init(&lock->wait_lock);
+#endif
debug_rt_mutex_proxy_lock(lock, proxy_owner);
rt_mutex_set_owner(lock, proxy_owner);
}
@@ -1723,6 +2323,26 @@
{
debug_rt_mutex_proxy_unlock(lock);
rt_mutex_set_owner(lock, NULL);
+}
+
+static void fixup_rt_mutex_blocked(struct rt_mutex *lock)
+{
+ struct task_struct *tsk = current;
+ /*
+ * RT has a problem here when the wait got interrupted by a timeout
+ * or a signal. task->pi_blocked_on is still set. The task must
+ * acquire the hash bucket lock when returning from this function.
+ *
+ * If the hash bucket lock is contended then the
+ * BUG_ON(rt_mutex_real_waiter(task->pi_blocked_on)) in
+ * task_blocks_on_rt_mutex() will trigger. This can be avoided by
+ * clearing task->pi_blocked_on which removes the task from the
+ * boosting chain of the rtmutex. That's correct because the task
+ * is not longer blocked on it.
+ */
+ raw_spin_lock(&tsk->pi_lock);
+ tsk->pi_blocked_on = NULL;
+ raw_spin_unlock(&tsk->pi_lock);
}
/**
@@ -1755,6 +2375,34 @@
if (try_to_take_rt_mutex(lock, task, NULL))
return 1;
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * In PREEMPT_RT there's an added race.
+ * If the task, that we are about to requeue, times out,
+ * it can set the PI_WAKEUP_INPROGRESS. This tells the requeue
+ * to skip this task. But right after the task sets
+ * its pi_blocked_on to PI_WAKEUP_INPROGRESS it can then
+ * block on the spin_lock(&hb->lock), which in RT is an rtmutex.
+ * This will replace the PI_WAKEUP_INPROGRESS with the actual
+ * lock that it blocks on. We *must not* place this task
+ * on this proxy lock in that case.
+ *
+ * To prevent this race, we first take the task's pi_lock
+ * and check if it has updated its pi_blocked_on. If it has,
+ * we assume that it woke up and we return -EAGAIN.
+ * Otherwise, we set the task's pi_blocked_on to
+ * PI_REQUEUE_INPROGRESS, so that if the task is waking up
+ * it will know that we are in the process of requeuing it.
+ */
+ raw_spin_lock(&task->pi_lock);
+ if (task->pi_blocked_on) {
+ raw_spin_unlock(&task->pi_lock);
+ return -EAGAIN;
+ }
+ task->pi_blocked_on = PI_REQUEUE_INPROGRESS;
+ raw_spin_unlock(&task->pi_lock);
+#endif
+
/* We enforce deadlock detection for futexes */
ret = task_blocks_on_rt_mutex(lock, waiter, task,
RT_MUTEX_FULL_CHAINWALK);
@@ -1768,6 +2416,9 @@
*/
ret = 0;
}
+
+ if (ret)
+ fixup_rt_mutex_blocked(lock);
debug_rt_mutex_print_deadlock(waiter);
@@ -1854,12 +2505,15 @@
raw_spin_lock_irq(&lock->wait_lock);
/* sleep on the mutex */
set_current_state(TASK_INTERRUPTIBLE);
- ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter, NULL);
/*
* try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
* have to fix that up.
*/
fixup_rt_mutex_waiters(lock);
+ if (ret)
+ fixup_rt_mutex_blocked(lock);
+
raw_spin_unlock_irq(&lock->wait_lock);
return ret;
@@ -1921,3 +2575,99 @@
return cleanup;
}
+
+static inline int
+ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+ unsigned tmp;
+
+ if (ctx->deadlock_inject_countdown-- == 0) {
+ tmp = ctx->deadlock_inject_interval;
+ if (tmp > UINT_MAX/4)
+ tmp = UINT_MAX;
+ else
+ tmp = tmp*2 + tmp + tmp/2;
+
+ ctx->deadlock_inject_interval = tmp;
+ ctx->deadlock_inject_countdown = tmp;
+ ctx->contending_lock = lock;
+
+ ww_mutex_unlock(lock);
+
+ return -EDEADLK;
+ }
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+int __sched
+ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0,
+ ctx ? &ctx->dep_map : NULL, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0,
+ ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ctx && ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ww_mutex_lock_interruptible);
+
+int __sched
+ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
+{
+ int ret;
+
+ might_sleep();
+
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0,
+ ctx ? &ctx->dep_map : NULL, _RET_IP_);
+ ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0,
+ ctx);
+ if (ret)
+ mutex_release(&lock->base.dep_map, 1, _RET_IP_);
+ else if (!ret && ctx && ctx->acquired > 1)
+ return ww_mutex_deadlock_injection(lock, ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ww_mutex_lock);
+
+void __sched ww_mutex_unlock(struct ww_mutex *lock)
+{
+ int nest = !!lock->ctx;
+
+ /*
+ * The unlocking fastpath is the 0->1 transition from 'locked'
+ * into 'unlocked' state:
+ */
+ if (nest) {
+#ifdef CONFIG_DEBUG_MUTEXES
+ DEBUG_LOCKS_WARN_ON(!lock->ctx->acquired);
+#endif
+ if (lock->ctx->acquired > 0)
+ lock->ctx->acquired--;
+ lock->ctx = NULL;
+ }
+
+ mutex_release(&lock->base.dep_map, nest, _RET_IP_);
+ __rt_mutex_unlock(&lock->base.lock);
+}
+EXPORT_SYMBOL(ww_mutex_unlock);
+
+int __rt_mutex_owner_current(struct rt_mutex *lock)
+{
+ return rt_mutex_owner(lock) == current;
+}
+EXPORT_SYMBOL(__rt_mutex_owner_current);
+#endif
--
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