Commit 6947bea4 authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Cleanups in preparation for the SCX_TASK_INIT_BEGIN/DEAD work 



Cleanups in preparation for the state-machine work that follows:

- Convert three sub-sched call sites that open-code
  rcu_assign_pointer(p->scx.sched, ...) to scx_set_task_sched().

- Move scx_get_task_state()/scx_set_task_state() above the SCX task iter
  section so scx_task_iter_next_locked() can use them without a forward
  declaration.

No functional change.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarAndrea Righi <arighi@nvidia.com>
parent ab28a067

kernel/sched/ext.c

+38 −38
Original line number Diff line number Diff line
@@ -711,6 +711,41 @@ struct bpf_iter_scx_dsq { 
} __attribute__((aligned(8)));





static u32 scx_get_task_state(const struct task_struct *p)

{

	return p->scx.flags & SCX_TASK_STATE_MASK;

}



static void scx_set_task_state(struct task_struct *p, u32 state)

{

	u32 prev_state = scx_get_task_state(p);

	bool warn = false;



	switch (state) {

	case SCX_TASK_NONE:

		break;

	case SCX_TASK_INIT:

		warn = prev_state != SCX_TASK_NONE;

		break;

	case SCX_TASK_READY:

		warn = prev_state == SCX_TASK_NONE;

		break;

	case SCX_TASK_ENABLED:

		warn = prev_state != SCX_TASK_READY;

		break;

	default:

		WARN_ONCE(1, "sched_ext: Invalid task state %d -> %d for %s[%d]",

			  prev_state, state, p->comm, p->pid);

		return;

	}



	WARN_ONCE(warn, "sched_ext: Invalid task state transition 0x%x -> 0x%x for %s[%d]",

		  prev_state, state, p->comm, p->pid);



	p->scx.flags &= ~SCX_TASK_STATE_MASK;

	p->scx.flags |= state;

}



/*

 * SCX task iterator.

 */
@@ -3499,41 +3534,6 @@ static struct cgroup *tg_cgrp(struct task_group *tg) 


#endif	/* CONFIG_EXT_GROUP_SCHED */



static u32 scx_get_task_state(const struct task_struct *p)

{

	return p->scx.flags & SCX_TASK_STATE_MASK;

}



static void scx_set_task_state(struct task_struct *p, u32 state)

{

	u32 prev_state = scx_get_task_state(p);

	bool warn = false;



	switch (state) {

	case SCX_TASK_NONE:

		break;

	case SCX_TASK_INIT:

		warn = prev_state != SCX_TASK_NONE;

		break;

	case SCX_TASK_READY:

		warn = prev_state == SCX_TASK_NONE;

		break;

	case SCX_TASK_ENABLED:

		warn = prev_state != SCX_TASK_READY;

		break;

	default:

		WARN_ONCE(1, "sched_ext: Invalid task state %d -> %d for %s[%d]",

			  prev_state, state, p->comm, p->pid);

		return;

	}



	WARN_ONCE(warn, "sched_ext: Invalid task state transition 0x%x -> 0x%x for %s[%d]",

		  prev_state, state, p->comm, p->pid);



	p->scx.flags &= ~SCX_TASK_STATE_MASK;

	p->scx.flags |= state;

}



static int __scx_init_task(struct scx_sched *sch, struct task_struct *p, bool fork)

{

	int ret;
@@ -5696,7 +5696,7 @@ static void scx_fail_parent(struct scx_sched *sch, 


		scoped_guard (sched_change, p, DEQUEUE_SAVE | DEQUEUE_MOVE) {

			scx_disable_and_exit_task(sch, p);

			rcu_assign_pointer(p->scx.sched, parent);

			scx_set_task_sched(p, parent);

		}

	}

	scx_task_iter_stop(&sti);
@@ -5783,7 +5783,7 @@ static void scx_sub_disable(struct scx_sched *sch) 
			 */

			scx_disable_and_exit_task(sch, p);

			scx_set_task_state(p, SCX_TASK_INIT);

			rcu_assign_pointer(p->scx.sched, parent);

			scx_set_task_sched(p, parent);

			scx_set_task_state(p, SCX_TASK_READY);

			scx_enable_task(parent, p);

		}
@@ -7212,7 +7212,7 @@ static void scx_sub_enable_workfn(struct kthread_work *work) 
			 * $p is now only initialized for @sch and READY, which

			 * is what we want. Assign it to @sch and enable.

			 */

			rcu_assign_pointer(p->scx.sched, sch);

			scx_set_task_sched(p, sch);

			scx_enable_task(sch, p);



			p->scx.flags &= ~SCX_TASK_SUB_INIT;