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    SubjectRe: IO scheduler based IO controller V10
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    On Mon, 2009-09-28 at 13:48 -0400, Vivek Goyal wrote:

    > Hmm.., so close to 25% reduction on average in completion time of konsole.
    > But this is in presece of writer. Does this help even in presence of 1 or
    > more sequential readers going?

    Dunno, I've only tested sequential writer.

    > So here latency seems to be coming from three sources.
    >
    > - Wait in CFQ before request is dispatched (only in case of competing seq readers).
    > - seek latencies
    > - latencies because of bigger requests are already dispatched to disk.
    >
    > So limiting the size of request will help with third factor but not with first
    > two factors and here seek latencies seem to be the biggest contributor.

    Yeah, seek latency seems to dominate.

    -Mike



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