Messages in this thread | | | From | Joel Fernandes <> | Date | Tue, 4 Jul 2023 13:28:10 -0400 | Subject | Re: [RFC PATCH V3 4/6] sched/deadline: Introduce deadline servers |
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On Tue, Jul 4, 2023 at 1:25 PM Joel Fernandes <joel@joelfernandes.org> wrote: > > On Tue, Jul 4, 2023 at 11:52 AM Daniel Bristot de Oliveira > <bristot@redhat.com> wrote: > > > > > > Back from EOSS... > > > > On 6/23/23 18:47, Valentin Schneider wrote: > > > On 08/06/23 17:58, Daniel Bristot de Oliveira wrote: > > >> @@ -2033,9 +2147,20 @@ static struct task_struct *pick_next_task_dl(struct rq *rq) > > >> struct task_struct *p; > > >> > > >> p = pick_task_dl(rq); > > >> - if (p) > > >> + if (!p) > > >> + return p; > > >> + > > >> + /* > > >> + * XXX: re-check !dl_server, changed from v2 because of > > >> + * pick_next_task_dl change > > >> + */ > > >> + if (!dl_server(&p->dl)) > > >> set_next_task_dl(rq, p, true); > > >> > > > > > > Should this be > > > > > > if (!p->server) > > > > > > instead? AFAICT dl_server(&p->dl) can never be true since there's no > > > pi_se-like link to the server via the dl_se, only via the task_struct, and > > > the server pick cannot return the server itself (as it's a pure sched_entity). > > > > makes sense... I will check that in the v4. > > Makes sense to me too. Since p is either a real DL task or a CFS task, > "if (dl_server(&p->dl))" is incorrect. "if (p->server)" is the right > check.
Grr, "if (!p->server)" I mean. Which ensures that set_next_task_dl() is not called on a non-DL task.
- Joel
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