Messages in this thread | | | Date | Fri, 17 May 2013 02:26:12 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v5 0/8] KVM: MMU: fast zap all shadow pages |
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On 05/16/2013 10:36 PM, Takuya Yoshikawa wrote: > On Thu, 16 May 2013 20:17:45 +0800 > Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> wrote: > >> Bechmark result: >> I have tested this patchset and the previous version that only zaps the >> pages linked on invalid slot's rmap. The benchmark is written by myself >> which has been attached, it writes large memory when do pci rom read. >> >> Host: Intel(R) Xeon(R) CPU X5690 @ 3.47GHz + 36G Memory >> Guest: 12 VCPU + 32G Memory >> >> Current code: This patchset Previous Version >> 2405434959 ns 2323016424 ns 2368810003 ns >> >> The interesting thing is, the previous version is slower than this patch, >> i guess the reason is that the former keeps lots of invalid pages in mmu >> which cause shadow page to be reclaimed due to used-pages > request-pages >> or host memory shrink. > > This patch series looks very nice!
Thank you, Takuya!
> > Minor issues may still need to be improved, but I really hope to see this > get merged during this cycle. > > [for the future] Do you think that postponing some zapping/freeing of > obsolete(already invalidated) pages to make_mmu_pages_available() time > can improve the situation more? -- say, for big guests.
Yes, i think it can. :)
We have made many efforts on this but still lack a straight way to achieve it.
> > If accounting kept correct, make_mmu_pages_available() only needs to free > some obsolete pages instead of valid pages. >
Yes.
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