Commit 85019c16 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

sched/wakeup: Reorganize the current::__state helpers 



In order to avoid more duplicate implementations for the debug and
non-debug variants of the state change macros, split the debug portion out
and make that conditional on CONFIG_DEBUG_ATOMIC_SLEEP=y.

Suggested-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.200898048@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent cd781d0c

include/linux/sched.h

+23 −25
Original line number Diff line number Diff line
@@ -123,8 +123,6 @@ struct task_group; 


#define task_is_stopped_or_traced(task)	((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0)



#ifdef CONFIG_DEBUG_ATOMIC_SLEEP



/*

 * Special states are those that do not use the normal wait-loop pattern. See

 * the comment with set_special_state().
@@ -132,30 +130,24 @@ struct task_group; 
#define is_special_task_state(state)				\

	((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))



#define __set_current_state(state_value)			\

	do {							\

		WARN_ON_ONCE(is_special_task_state(state_value));\

		current->task_state_change = _THIS_IP_;		\

		WRITE_ONCE(current->__state, (state_value));	\

	} while (0)



#define set_current_state(state_value)				\

#ifdef CONFIG_DEBUG_ATOMIC_SLEEP

# define debug_normal_state_change(state_value)				\

	do {								\

		WARN_ON_ONCE(is_special_task_state(state_value));	\

		current->task_state_change = _THIS_IP_;			\

		smp_store_mb(current->__state, (state_value));	\

	} while (0)



#define set_special_state(state_value)					\

# define debug_special_state_change(state_value)			\

	do {								\

		unsigned long flags; /* may shadow */			\

		WARN_ON_ONCE(!is_special_task_state(state_value));	\

		raw_spin_lock_irqsave(&current->pi_lock, flags);	\

		current->task_state_change = _THIS_IP_;			\

		WRITE_ONCE(current->__state, (state_value));		\

		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\

	} while (0)



#else

# define debug_normal_state_change(cond)	do { } while (0)

# define debug_special_state_change(cond)	do { } while (0)

#endif



/*

 * set_current_state() includes a barrier so that the write of current->state

 * is correctly serialised wrt the caller's subsequent test of whether to
@@ -194,27 +186,33 @@ struct task_group; 
 * Also see the comments of try_to_wake_up().

 */

#define __set_current_state(state_value)				\

	WRITE_ONCE(current->__state, (state_value))

	do {								\

		debug_normal_state_change((state_value));		\

		WRITE_ONCE(current->__state, (state_value));		\

	} while (0)



#define set_current_state(state_value)					\

	smp_store_mb(current->__state, (state_value))

	do {								\

		debug_normal_state_change((state_value));		\

		smp_store_mb(current->__state, (state_value));		\

	} while (0)



/*

 * set_special_state() should be used for those states when the blocking task

 * can not use the regular condition based wait-loop. In that case we must

 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores

 * will not collide with our state change.

 * serialize against wakeups such that any possible in-flight TASK_RUNNING

 * stores will not collide with our state change.

 */

#define set_special_state(state_value)					\

	do {								\

		unsigned long flags; /* may shadow */			\

									\

		raw_spin_lock_irqsave(&current->pi_lock, flags);	\

		debug_special_state_change((state_value));		\

		WRITE_ONCE(current->__state, (state_value));		\

		raw_spin_unlock_irqrestore(&current->pi_lock, flags);	\

	} while (0)



#endif



#define get_current_state()	READ_ONCE(current->__state)



/* Task command name length: */