Commit fbaa6a18 authored by Elliot Berman's avatar Elliot Berman Committed by Ingo Molnar
Browse files

sched/core: Remove ifdeffery for saved_state 



In preparation for freezer to also use saved_state, remove the
CONFIG_PREEMPT_RT compilation guard around saved_state.

On the arm64 platform I tested which did not have CONFIG_PREEMPT_RT,
there was no statistically significant deviation by applying this patch.

Test methodology:

perf bench sched message -g 40 -l 40

Signed-off-by: default avatarElliot Berman <quic_eberman@quicinc.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4ff34ad3

include/linux/sched.h

+0 −2
Original line number Diff line number Diff line
@@ -750,10 +750,8 @@ struct task_struct { 
#endif

	unsigned int			__state;



#ifdef CONFIG_PREEMPT_RT

	/* saved state for "spinlock sleepers" */

	unsigned int			saved_state;

#endif



	/*

	 * This begins the randomizable portion of task_struct. Only

kernel/sched/core.c

+2 −6
Original line number Diff line number Diff line
@@ -2232,23 +2232,20 @@ int __task_state_match(struct task_struct *p, unsigned int state) 
	if (READ_ONCE(p->__state) & state)

		return 1;



#ifdef CONFIG_PREEMPT_RT

	if (READ_ONCE(p->saved_state) & state)

		return -1;

#endif



	return 0;

}



static __always_inline

int task_state_match(struct task_struct *p, unsigned int state)

{

#ifdef CONFIG_PREEMPT_RT

	/*

	 * Serialize against current_save_and_set_rtlock_wait_state() and

	 * current_restore_rtlock_saved_state().

	 */

	guard(raw_spinlock_irq)(&p->pi_lock);

#endif

	return __task_state_match(p, state);

}
@@ -4038,7 +4035,6 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) 


	*success = !!(match = __task_state_match(p, state));



#ifdef CONFIG_PREEMPT_RT

	/*

	 * Saved state preserves the task state across blocking on

	 * an RT lock.  If the state matches, set p::saved_state to
@@ -4054,7 +4050,7 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) 
	 */

	if (match < 0)

		p->saved_state = TASK_RUNNING;

#endif



	return match > 0;

}