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    SubjectRe: [RFC PATCH V3 4/6] sched/deadline: Introduce deadline servers
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    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.

    >
    >> + /* XXX not quite right */
    >> + if (hrtick_enabled(rq))
    >> + start_hrtick_dl(rq, &p->dl);
    >> +
    >
    > IIUC that got hauled out of set_next_task_dl() to cover the case where we
    > pick the server (+ the server pick) and want to more thoroughly enforce the
    > server's bandwidth. If so, what's the issue with starting the hrtick here?

    I think that the commend was added more as a check if it is correct... it seems it is.

    Thanks Vale!
    -- Daniel

    >
    >> return p;
    >> }
    >>
    >

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