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Diffstat (limited to 'kernel/locking/mutex.c')
-rw-r--r--kernel/locking/mutex.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index a39ecccbd106..de7d6702cd96 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -191,9 +191,7 @@ static void
__mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct list_head *list)
{
-#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
hung_task_set_blocker(lock, BLOCKER_TYPE_MUTEX);
-#endif
debug_mutex_add_waiter(lock, waiter, current);
list_add_tail(&waiter->list, list);
@@ -209,9 +207,7 @@ __mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter)
__mutex_clear_flag(lock, MUTEX_FLAGS);
debug_mutex_remove_waiter(lock, waiter, current);
-#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
hung_task_clear_blocker();
-#endif
}
/*
@@ -644,6 +640,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
goto err_early_kill;
}
+ __set_task_blocked_on(current, lock);
set_current_state(state);
trace_contention_begin(lock, LCB_F_MUTEX);
for (;;) {
@@ -680,6 +677,12 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
first = __mutex_waiter_is_first(lock, &waiter);
+ /*
+ * As we likely have been woken up by task
+ * that has cleared our blocked_on state, re-set
+ * it to the lock we are trying to acquire.
+ */
+ set_task_blocked_on(current, lock);
set_current_state(state);
/*
* Here we order against unlock; we must either see it change
@@ -691,8 +694,15 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
if (first) {
trace_contention_begin(lock, LCB_F_MUTEX | LCB_F_SPIN);
+ /*
+ * mutex_optimistic_spin() can call schedule(), so
+ * clear blocked on so we don't become unselectable
+ * to run.
+ */
+ clear_task_blocked_on(current, lock);
if (mutex_optimistic_spin(lock, ww_ctx, &waiter))
break;
+ set_task_blocked_on(current, lock);
trace_contention_begin(lock, LCB_F_MUTEX);
}
@@ -700,6 +710,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
}
raw_spin_lock_irqsave(&lock->wait_lock, flags);
acquired:
+ __clear_task_blocked_on(current, lock);
__set_current_state(TASK_RUNNING);
if (ww_ctx) {
@@ -729,9 +740,11 @@ skip_wait:
return 0;
err:
+ __clear_task_blocked_on(current, lock);
__set_current_state(TASK_RUNNING);
__mutex_remove_waiter(lock, &waiter);
err_early_kill:
+ WARN_ON(__get_task_blocked_on(current));
trace_contention_end(lock, ret);
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
debug_mutex_free_waiter(&waiter);
@@ -942,6 +955,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
next = waiter->task;
debug_mutex_wake_waiter(lock, waiter);
+ __clear_task_blocked_on(next, lock);
wake_q_add(&wake_q, next);
}