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    SubjectRe: CPU affinity & IPI latency
    > If the amount of data/instructions needed by all 5 processes fits in the 
    > cache and you pin all the processes to the same CPU you'll get much
    > better performance than simply letting them float.

    interesting. I remember that around 2.3.40, the scheduler handled
    "frequent-schedulers" (like lat_ctx) differently, based on how long
    a timeslice the proc used, relative to the estimated time to flush cache.

    as I recall, it let them stay on their current CPU. like letting
    someone with 1 item go ahead of you in a grocery store checkout ;)

    that code is mostly gone (only cacheflush_time remains); I think it
    morphed into the current migrate-to-longest-idle heuristic.

    does anyone remember why the frequent-schedulers code was killed?
    just because it conflated cache-affinity with timeslice?

    regards, mark hahn.

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