Messages in this thread | | | From | "Wang, Wei W" <> | Subject | RE: [PATCH v1] KVM/x86/vPMU: Guest PMI Optimization | Date | Sat, 13 Oct 2018 02:21:19 +0000 |
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On Saturday, October 13, 2018 12:31 AM, Andi Kleen wrote: > > 4. Results > > - Without this optimization, the guest pmi handling time is > > ~4500000 ns, and the max sampling rate is reduced to 250. > > - With this optimization, the guest pmi handling time is ~9000 ns > > (i.e. 1 / 500 of the non-optimization case), and the max sampling > > rate remains at the original 100000. > > Impressive performance improvement! > > It's not clear to me why you're special casing PMIs here. The optimization > should work generically, right?
Yes, seems doable. I plan to try some lazy approach for the perf event allocation.
> Is that guaranteed to be always called on the right CPU that will run the vcpu? > > AFAIK there's an ioctl to set MSRs in the guest from qemu, I'm pretty sure it > won't handle that.
Thanks, will consider that case.
Best, Wei
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