Commit 26176116 authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Count SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE in the right spot 



SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE wasn't quite right in two aspects:

- It counted both migration disabled and offline events.

- It didn't count events from scx_bpf_dsq_move() path.

Fix it by moving the counting into task_can_run_on_remote_rq() which is
shared by both paths and can distinguish the different rejection conditions.
The argument @trigger_error is renamed to @enforce as it now does more than
just triggering error.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarChangwoo Min <changwoo@igalia.com>
parent 46a0e161

kernel/sched/ext.c

+7 −5
Original line number Diff line number Diff line
@@ -2431,7 +2431,7 @@ static void move_remote_task_to_local_dsq(struct task_struct *p, u64 enq_flags, 
 * The caller must ensure that @p and @rq are on different CPUs.

 */

static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq,

				      bool trigger_error)

				      bool enforce)

{

	int cpu = cpu_of(rq);
@@ -2444,7 +2444,7 @@ static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq, 
	 * picked CPU is outside the allowed mask.

	 */

	if (!task_allowed_on_cpu(p, cpu)) {

		if (trigger_error)

		if (enforce)

			scx_ops_error("SCX_DSQ_LOCAL[_ON] verdict target cpu %d not allowed for %s[%d]",

				      cpu_of(rq), p->comm, p->pid);

		return false;
@@ -2456,8 +2456,11 @@ static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq, 
	 */

	SCHED_WARN_ON(is_migration_disabled(p));



	if (!scx_rq_online(rq))

	if (!scx_rq_online(rq)) {

		if (enforce)

			__scx_add_event(SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE, 1);

		return false;

	}



	return true;

}
@@ -2527,7 +2530,7 @@ static bool consume_remote_task(struct rq *this_rq, struct task_struct *p, 
}

#else	/* CONFIG_SMP */

static inline void move_remote_task_to_local_dsq(struct task_struct *p, u64 enq_flags, struct rq *src_rq, struct rq *dst_rq) { WARN_ON_ONCE(1); }

static inline bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq, bool trigger_error) { return false; }

static inline bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq, bool enforce) { return false; }

static inline bool consume_remote_task(struct rq *this_rq, struct task_struct *p, struct scx_dispatch_q *dsq, struct rq *task_rq) { return false; }

#endif	/* CONFIG_SMP */
@@ -2717,7 +2720,6 @@ static void dispatch_to_local_dsq(struct rq *rq, struct scx_dispatch_q *dst_dsq, 
	    unlikely(!task_can_run_on_remote_rq(p, dst_rq, true))) {

		dispatch_enqueue(find_global_dsq(p), p,

				 enq_flags | SCX_ENQ_CLEAR_OPSS);

		__scx_add_event(SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE, 1);

		return;

	}