On Fri, May 08, 2009 at 10:45:52AM -0400, Gregory Haskins wrote: > Marcelo Tosatti wrote: > > On Fri, May 08, 2009 at 10:55:37AM +0300, Avi Kivity wrote: > > > >> Marcelo Tosatti wrote: > >> > >>> Also it would be interesting to see the MMIO comparison with EPT/NPT, > >>> it probably sucks much less than what you're seeing. > >>> > >>> > >> Why would NPT improve mmio? If anything, it would be worse, since the > >> processor has to do the nested walk. > >> > >> Of course, these are newer machines, so the absolute results as well as > >> the difference will be smaller. > >> > > > > Quad-Core AMD Opteron(tm) Processor 2358 SE 2.4GHz: > > > > NPT enabled: > > test 0: 3088633284634 - 3059375712321 = 29257572313 > > test 1: 3121754636397 - 3088633419760 = 33121216637 > > test 2: 3204666462763 - 3121754668573 = 82911794190 > > > > NPT disabled: > > test 0: 3638061646250 - 3609416811687 = 28644834563 > > test 1: 3669413430258 - 3638061771291 = 31351658967 > > test 2: 3736287253287 - 3669413463506 = 66873789781 > > > > > Thanks for running that. Its interesting to see that NPT was in fact > worse as Avi predicted. > > Would you mind if I graphed the result and added this data to my wiki? > If so, could you adjust the tsc result into IOPs using the proper > time-base and the test_count you ran with? I can show a graph with the > data as is and the relative differences will properly surface..but it > would be nice to have apples to apples in terms of IOPS units with my > other run. > > -Greg Please, that'll be nice. Quad-Core AMD Opteron(tm) Processor 2358 SE host: 2.6.30-rc2 guest: 2.6.29.1-102.fc11.x86_64 test_count=1000000, tsc freq=2402882804 Hz NPT disabled: test 0 = 2771200766 test 1 = 3018726738 test 2 = 6414705418 test 3 = 2890332864 NPT enabled: test 0 = 2908604045 test 1 = 3174687394 test 2 = 7912464804 test 3 = 3046085805 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
