lkml.org 
[lkml]   [2020]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v3 6/6] sched/rt: Fix pushing unfit tasks to a better CPU
    On Mon,  2 Mar 2020 13:27:21 +0000
    Qais Yousef <qais.yousef@arm.com> wrote:

    > + * Don't bother moving it if the destination CPU is
    > + * not running a lower priority task.
    > + */
    > + if (p->prio < cpu_rq(target)->rt.highest_prio.curr) {
    > +
    > + cpu = target;
    > +
    > + } else if (p->prio == cpu_rq(target)->rt.highest_prio.curr) {
    > +
    > + /*
    > + * If the priority is the same and the new CPU
    > + * is a better fit, then move, otherwise don't
    > + * bother here either.
    > + */
    > + if (fit_target)
    > + cpu = target;
    > + }

    BTW, A little better algorithm would be to test fit_target first:

    target_prio = cpu_rq(target)->rt.hightest_prio.curr;
    if (p->prio < target_prio) {
    cpu = target;

    } else if (fit_target && p->prio == target_prio) {
    cpu = target;
    }

    Which can also just be a single if statement:

    if (p->prio < target_prio ||
    (fit_target && p->prio == target_prio)
    cpu = target;

    -- Steve

    \
     
     \ /
      Last update: 2020-03-11 15:01    [W:4.249 / U:0.040 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site