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    SubjectRe: [PATCH] cpuidle: avoid using smp_processor_id() in preemptible code (nr_iowait_cpu) v4
    On (06/16/10 23:59), Andrew Morton wrote:
    > [..] if someone runs
    > update_ts_time_stats() before the initcalls then conceivably the
    > `swapper' process's accounting will go a little bit wrong, but I doubt
    > it.

    That was the sing that scared me - update_ts_time_stats call before init.
    Having ".cpu = cpu" in tick_get_tick_sched guarantees correct .cpu and...
    and it sucks.

    > Still, it'd be better to do it earlier, I guess. tick_init() is called
    > super-early and that would be a good place. tick_init() is presently a
    > no-op if !CONFIG_GENERIC_CLOCKEVENTS, but all this code depends on
    > So how does this look? If "OK" then would you be able to test it please?
    I'll test it in 2 hours. Thanks.

    > [ Sigh. The field tick_sched.cpu shouldn't even exist on
    > uniprocessor builds. Ifdeffing it away is trivial and a bit messy,
    > but it's still only a partial solution. Passing the `cpu' argument
    > to nr_iowait_cpu() will generate additional code, and it's unneeded
    > on uniprocessor builds.]
    You're right.

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