Messages in this thread | | | Date | Fri, 14 Mar 2008 14:08:36 -0700 (PDT) | From | Christoph Lameter <> | Subject | Re: hackbench regression since 2.6.25-rc |
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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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