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    SubjectRe: Industry db benchmark result on recent 2.6 kernels
    Chen, Kenneth W wrote:
    > Ingo Molnar wrote on Thursday, March 31, 2005 8:52 PM
    >>the current defaults for cache_hot_time are 10 msec for NUMA domains,
    >>and 2.5 msec for SMP domains. Clearly too low for CPUs with 9MB cache.
    >>Are you increasing cache_hot_time in your experiment? If that solves
    >>most of the problem that would be an easy thing to fix for 2.6.12.
    > Chen, Kenneth W wrote on Thursday, March 31, 2005 9:15 PM
    >>Yes, we are increasing the number in our experiments. It's in the queue
    >>and I should have a result soon.
    > Hot of the press: bumping up cache_hot_time to 10ms on our db setup brings
    > 2.6.11 performance on par with 2.6.9. Theory confirmed.

    OK, that's good. I'll look at whether we can easily use Ingo's
    tool on the SMP domain only, to avoid the large O(n^2). That might
    be an acceptable short term solution for 2.6.12.

    If you get a chance to also look at those block layer patches that
    would be good - if they give you a nice improvement, that would
    justify getting them into -mm.

    SUSE Labs, Novell Inc.

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