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    SubjectRe: [PATCH 1/2] sched/fair: move cpufreq hook to update_cfs_rq_load_avg()
    On Thu, Mar 31, 2016 at 11:50:40AM +0200, Vincent Guittot wrote:
    > > In what case? Assuming you talk about a remove wakeup, no. Only if that
    > > wakeup results in a preemption, which isn't a given.
    >
    > yes, i was speaking about a remote wakeup.
    > In the ttwu_queue_remote, there is a call to smp_send_reschedule. Is
    > there another way to add a remote task in the wake list ?

    Right, but at that point we don't yet know how much util will change.

    And doing that IPI unconditionally is expensive; see:

    518cd6234178 ("sched: Only queue remote wakeups when crossing cache boundaries")

    13% regression on TCP_RR.

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