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    SubjectRe: hackbench regression since 2.6.25-rc
    On Fri, 14 Mar 2008, Zhang, Yanmin wrote:

    > > Ahhh... Okay those slabs did not change for 2.6.25-rc. Is there
    > > really a difference to 2.6.24?
    > As oprofile shows slub functions spend more than 80% cpu time, I would like
    > to focus on optimizing SLUB before going back to 2.6.24.

    I thought you wanted to address a regression vs 2.6.24?

    > kmalloc-512: No NUMA information available.
    >
    > Slab Perf Counter Alloc Free %Al %Fr
    > --------------------------------------------------
    > Fastpath 55039159 5006829 68 6
    > Slowpath 24975754 75007769 31 93
    > Page Alloc 73840 73779 0 0
    > Add partial 0 24341085 0 30
    > Remove partial 24267297 73779 30 0

    ^^^ add partial/remove partial is likely the cause for
    trouble here. 30% is unacceptably high. The larger allocs will reduce the
    partial handling overhead. That is likely the effect that we see here.

    > Refill 24975738

    Duh refills at 50%? We could try to just switch to another slab instead of
    reusing the existing one. May also affect the add/remove partial
    situation.





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