* - The BPF scheduler is bypassed while the rq is offline and we can always say
* no to the BPF scheduler initiated migrations while offline.
*/
-static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq)
+static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq,
+ bool trigger_error)
{
int cpu = cpu_of(rq);
- if (!task_allowed_on_cpu(p, cpu))
+ /*
+ * We don't require the BPF scheduler to avoid dispatching to offline
+ * CPUs mostly for convenience but also because CPUs can go offline
+ * between scx_bpf_dispatch() calls and here. Trigger error iff the
+ * picked CPU is outside the allowed mask.
+ */
+ if (!task_allowed_on_cpu(p, cpu)) {
+ if (trigger_error)
+ 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;
+ }
+
if (unlikely(is_migration_disabled(p)))
return false;
+
if (!scx_rq_online(rq))
return false;
+
return true;
}
return move_task_to_local_dsq(p, 0, task_rq, rq);
}
#else /* CONFIG_SMP */
-static bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq) { return false; }
-static bool consume_remote_task(struct rq *rq, struct scx_dispatch_q *dsq,
- struct task_struct *p, struct rq *task_rq) { return false; }
+static inline bool task_can_run_on_remote_rq(struct task_struct *p, struct rq *rq, bool trigger_error) { return false; }
+static inline bool consume_remote_task(struct rq *rq, struct scx_dispatch_q *dsq, struct task_struct *p, struct rq *task_rq) { return false; }
#endif /* CONFIG_SMP */
static bool consume_dispatch_q(struct rq *rq, struct scx_dispatch_q *dsq)
return true;
}
- if (task_can_run_on_remote_rq(p, rq)) {
+ if (task_can_run_on_remote_rq(p, rq, false)) {
if (likely(consume_remote_task(rq, dsq, p, task_rq)))
return true;
goto retry;
}
#ifdef CONFIG_SMP
- if (cpumask_test_cpu(cpu_of(dst_rq), p->cpus_ptr)) {
+ if (likely(task_can_run_on_remote_rq(p, dst_rq, true))) {
bool dsp;
/*
raw_spin_rq_lock(src_rq);
}
- /*
- * We don't require the BPF scheduler to avoid dispatching to
- * offline CPUs mostly for convenience but also because CPUs can
- * go offline between scx_bpf_dispatch() calls and here. If @p
- * is destined to an offline CPU, queue it on its current CPU
- * instead, which should always be safe. As this is an allowed
- * behavior, don't trigger an ops error.
- */
- if (!scx_rq_online(dst_rq))
- dst_rq = src_rq;
-
if (src_rq == dst_rq) {
/*
* As @p is staying on the same rq, there's no need to
}
#endif /* CONFIG_SMP */
- scx_ops_error("SCX_DSQ_LOCAL[_ON] verdict target cpu %d not allowed for %s[%d]",
- cpu_of(dst_rq), p->comm, p->pid);
return DTL_INVALID;
}