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> > > > - /* see dequeue_task_scx() on why we skip when !QUEUED */ > > - if (SCX_HAS_OP(sch, running) && (p->scx.flags & SCX_TASK_QUEUED)) > > - SCX_CALL_OP_TASK(sch, running, rq, p); > > + /* > > + * See dequeue_task_scx() for why we skip when !QUEUED. On a normal > > + * scheduling transition, defer starting a blocked donor's session until > > + * proxy resolution succeeds. A restore follows an already resolved > > + * scheduling context and can start the session immediately. > > + */ > > + if ((p->scx.flags & SCX_TASK_QUEUED) && (!p->is_blocked || !first)) > > + scx_start_task_running(rq, p); > > nit: can we do !(p->is_blocked && first) instead? I think that matches > what's being expressed better. > > Also, can you expand the comment? I find it a bit difficult to follow. So, > when we're actually switching to a donor, we skip running transition because > proxy resolution might give us nothing or it may have to run on a differnet > CPU and so on, so we do running transition after proxy resolution is done. > For SAVE/RESTORE, this doesn't apply as they're always matched regardless of > donor state. Is that the right reading? Yes, that's the intended behavior. When @first is set, a blocked task is only a provisional donor: proxy-exec may fail or migrate the donor to another CPU, so ops.running() is deferred until resolution succeeds. When !@first, this is the restore side of a SAVE/RESTORE cycle, the matching dequeue already issued ops.stopping(), so ops.running() must be restarted regardless of the donor state. I'll change the condition and expand the comment. > > > clr_task_runnable(p, true); > > > > @@ -3072,6 +3090,13 @@ static void set_next_task_scx(struct rq *rq, struct task_struct *p, bool first) > > > > void scx_proxy_donor_start(struct rq *rq) > > { > > + struct task_struct *donor = rq->donor; > > + > > + lockdep_assert_rq_held(rq); > > + > > + if (donor->sched_class == &ext_sched_class && > > + (donor->scx.flags & SCX_TASK_QUEUED)) > > another nit: no need for line break. Ack. Thanks, -Andrea > > > + scx_start_task_running(rq, donor); > > } > > Thanks. > > -- > tejun