[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] HVM kernbench performance on Linux (2.6.27-rc4 vs.2.6.18.6-amd64)
> So it seems the problem doesn't occur for me on Debian 4.0 HVM guest, > as suggested by Gianluca Guida. > > The Debian 4.0 vanilla install has a 2.6.18.6-amd64 kernel. > > The results are below. So it seems that the guest kernel makes a big > difference. It sounds like the "find writeable mappings" heuristic might be broken for newer linux 64b kernels. That will be painful for shadow2, but catastrophic for shadow3. I wonder if there's a second 1:1 direct mapping added, or whether the direct mapping has moved? Ian > The performance problem is not seen on the debian kernel. > > HVM guest (Debian 4.0 vanilla 2.6.18.6-amd64) > > shadow2 > 2.6.18.6-amd64 guest kernel > Average Optimal load -j 4 Run (std deviation): > Elapsed Time 506.658 (4.13104) > User Time 364.536 (0.337757) > System Time 140.834 (4.04617) > Percent CPU 99 (0) > Context Switches 29803 (120.69) > Sleeps 37929.2 (355.421) > > shadow3 > 2.6.18.6-amd64 guest kernel > Average Optimal load -j 4 Run (std deviation): > Elapsed Time 489.58 (4.00024) > User Time 389.328 (0.614304) > System Time 98.838 (4.86796) > Percent CPU 99 (0) > Context Switches 29314.6 (196.596) > Sleeps 37773.6 (231.069) > > vs. the same machine and guest config with a 2.6.27-rc4 guest kernel > > > shadow2 > 2.6.27-rc4 guest kernel > Average Optimal load -j 4 Run (std deviation): > Elapsed Time 737.144 (5.19414) > User Time 498.508 (2.52895) > System Time 235.056 (2.71348) > Percent CPU 99 (0) > Context Switches 133127 (823.517) > Sleeps 36295.4 (124.088) > > > shadow 3 > 2.6.27-rc4 guest kernel > Average Optimal load -j 4 Run (std deviation): > Elapsed Time 2081.71 (34.0459) > User Time 617.36 (3.61771) > System Time 1430.36 (28.3309) > Percent CPU 98 (0) > Context Switches 331843 (5283.28) > Sleeps 37329.8 (91.538) > > _______________________________________________ > Xen-devel mailing list > Xen-devel@xxxxxxxxxxxxxxxxxxx > http://lists.xensource.com/xen-devel _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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