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    SubjectRe: 2.6.32 / RH 6.1 scheduler bloated
    Will try this, but I have older kernel version running on the same  
    hardware, with the same boot parameters, and showing a more
    reasonable 2us wakeup latency. Still high, but coming out of idle can
    be slow as you say.
    But 10us??

    On Oct 9, 2011, at 2:03 AM, Mike Galbraith wrote:

    > On Sat, 2011-10-08 at 20:26 -0400, Robert Kubrick wrote:
    >> A simple ftrace wakeup test shows 10us latency during the idle-to-run
    >> transition:
    > If you boot nohz=off idle=poll, and measure with cyclictest
    > (measure in
    > userspace for free), you'll likely see a remarkable difference.
    > Coming out of idle can be slow, but that has more to do with silicon
    > than scheduler bloat (not that bloat doesn't exist mind you). My
    > Q6600
    > box _sucks_ at getting off it's duff, even intel_idle.max_cstate=1 is
    > horrid. E5620 gets moving > order of magnitude more quickly with the
    > same kernel/config/params.
    > -Mike

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