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    SubjectRe: [PATCH v3 0/5] Improve newidle lb cost tracking and early abort
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    On Thu, 2021-10-28 at 14:15 +0200, Vincent Guittot wrote:
    >
    > > It seems to make sense to skip the call
    > > to nohz_newidle_balance() for this case?
    >
    > nohz_newidle_balance() also tests this condition :
    > (this_rq->avg_idle < sysctl_sched_migration_cost)
    > and doesn't set NOHZ_NEWILB_KICKi in such case
    >
    > But this patch now used the condition :
    > this_rq->avg_idle < sd->max_newidle_lb_cost
    > and sd->max_newidle_lb_cost can be higher than
    > sysctl_sched_migration_cost
    >
    > which means that we can set NOHZ_NEWILB_KICK:
    > -although we decided to skip newidle loop
    > -or when we abort because this_rq->avg_idle < curr_cost + sd-
    > >max_newidle_lb_cost
    >
    > This is even more true when sysctl_sched_migration_cost is lowered
    > which is your case IIRC
    >
    > The patch below ensures that we don't set NOHZ_NEWILB_KICK in such
    > cases:
    >

    Thanks. Will ask our benchmark team to give it a spin.

    Tim

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