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    SubjectRe: [PATCH 2/5] sched: pull only one task during NEWIDLE balancing to limit critical section
    On Tuesday 26 August 2008 06:15, Gregory Haskins wrote:
    > git-id c4acb2c0669c5c5c9b28e9d02a34b5c67edf7092 attempted to limit
    > newidle critical section length by stopping after at least one task
    > was moved. Further investigation has shown that there are other
    > paths nested further inside the algorithm which still remain that allow
    > long latencies to occur with newidle balancing. This patch applies
    > the same technique inside balance_tasks() to limit the duration of
    > this optional balancing operation.
    > Signed-off-by: Gregory Haskins <>
    > CC: Nick Piggin <>

    Hmm, this (andc4acb2c0669c5c5c9b28e9d02a34b5c67edf7092) still could
    increase the amount of work to do significantly for workloads where
    the CPU is going idle and pulling tasks over frequently. I don't
    really like either of them too much.

    Maybe increasing the limit would effectively amortize most of the
    problem (say, limit to move 16 tasks at most).

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      Last update: 2008-08-26 08:25    [W:0.019 / U:52.448 seconds]
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