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    SubjectRe: [PATCH] Preemption Latency Measurement Tool
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    Date
    On Wed, 2001-09-19 at 21:13, David Lang wrote:
    > also how useful is the latency info once swapping starts? if you have
    > something that gets swapped out it will have horrible latency and skew the
    > results (or at the very least you won't know if the problem is disk IO or
    > fixable problems)

    Its not that bad because the patch measures latency across points where
    preemption was enabled and disabled -- the various kernel locking
    mechanisms.

    Thus either page fault holds a lock and it is a legimate latency
    recorded over that specific lock, or it doesn't in which case its not an
    issue.

    --
    Robert M. Love
    rml at ufl.edu
    rml at tech9.net

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