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    SubjectRe: [RFC PATCH v3 0/5] Tunable sched_mc_power_savings=n
    * Peter Zijlstra <> [2008-11-10 19:50:16]:

    > a quick response, I'll read them more carefully tomorrow:

    Hi Peter,

    Thanks for the quick review.

    > - why are the preferred cpu things pointers? afaict using just the cpu
    > number is both smaller and clearer to the reader.

    I would need each cpu within a partitioned sched domain to point to
    the _same_ preferred wakeup cpu. The preferred CPU will be updated in
    one place in find_busiest_group() and used by wake_idle.

    If I have a per cpu value, then updating it for each cpu in the
    partitioned sched domain will be slow.

    The actual number of preferred_wakeup_cpu will be equal to the number
    of partitions. If there are no partitions in the sched domains, then
    then all per-cpu pointers will point to the same variable.

    > - in patch 5/5 you do:
    > + spin_unlock(&this_rq->lock);
    > + double_rq_lock(this_rq, busiest);
    > we call that double_lock_balance()

    Will fix this. Did not look for such a routine :)

    > - comments go like:
    > /*
    > * this is a multi-
    > * line comment
    > */

    Will fix this too.


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