Messages in this thread | | | From | "Ray Bryant" <> | Subject | Re: [PATCH/RFC] Shared page tables | Date | Mon, 30 Jan 2006 12:46:24 -0600 |
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On Friday 27 January 2006 16:50, Brian Twichell wrote: <snip>
> > Hi, > > We collected more granular performance data for the ppc64/hugepage case. > > CPI decreased by 3% when shared pagetables were used. Underlying this was > a 7% decrease in the overall TLB miss rate. The TLB miss rate for > hugepages decreased 39%. TLB miss rates are calculated per instruction > executed. >
Interesting.
Do you know if Dave's patch supports sharing of pte's for 2 MB pages on X86_64?
Was there a corresponding improvement in overall transaction throughput for the hugetlb, shared pte case? That is, did the 3% improvement in CPI translate to a measurable improvement in the overall OLTP benchmark score?
(I'm assuming your 25-50% improvement measurements, as mentioned in a previous note, was for small pages.)
> We didn't collect a profile per se, as we would expect a CPI improvement > of this nature to be spread over a significant number of functions, > mostly in user-space. > > Cheers, > Brian > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
-- Ray Bryant AMD Performance Labs Austin, Tx 512-602-0038 (o) 512-507-7807 (c)
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