Nakajima, Jun
2006-Aug-30 15:18 UTC
RE: [Xen-devel] [PATCH] Optimizing x86-64 xenlinux using global pagesfor user mode (take 2)
Andrew Theurer wrote:> Ian Pratt wrote: >>> The previous patch had a problem with the builder, which constructs >>> the initial page tables with the USER bit on. And Xen couldn''t >>> distinguish kernel or use pages. It was partially checked avoiding >>> the bug, and it''s finished with this patch. >> >> Thanks. Have you any updated benchmark numbers as the bug could have >> been giving quite a performance boost before.Looks like part of the boost was realized by the bug, but I still see consistent and visible improvements with lmbench. If I turn on the global bits for the kernel pages as well, I see more improvements, which are comparable with or better than before. I think we need to do macro benchmarks to see how this helps.> > FWIW, I had been running more extensive testing on changeset 11225 > (before global-bit) and 11229 (global-bit with revert/fix for dom0 > builder), and they do not match the initial testing I did with rev > 11118 + global_1 patch. In fact, I am not seeing really any > improvement. I am not sure what is wrong. Should I just test > xen-unstable-tip+newest_patch and see where we stand? >Yes, please. You shouldn''t have observed any performance difference between 11225 and 11229 because the changeset 11226 did not enable the global bit.> -Andrew TheurerJun --- Intel Open Source Technology Center _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Andrew Theurer
2006-Aug-30 15:26 UTC
Re: [Xen-devel] [PATCH] Optimizing x86-64 xenlinux using global pagesfor user mode (take 2)
Nakajima, Jun wrote:> Andrew Theurer wrote: > >> Ian Pratt wrote: >> >>>> The previous patch had a problem with the builder, which constructs >>>> the initial page tables with the USER bit on. And Xen couldn''t >>>> distinguish kernel or use pages. It was partially checked avoiding >>>> the bug, and it''s finished with this patch. >>>> >>> Thanks. Have you any updated benchmark numbers as the bug could have >>> been giving quite a performance boost before. >>> > > Looks like part of the boost was realized by the bug, but I still see > consistent and visible improvements with lmbench. If I turn on the > global bits for the kernel pages as well, I see more improvements, which > are comparable with or better than before. I think we need to do macro > benchmarks to see how this helps. > > >> FWIW, I had been running more extensive testing on changeset 11225 >> (before global-bit) and 11229 (global-bit with revert/fix for dom0 >> builder), and they do not match the initial testing I did with rev >> 11118 + global_1 patch. In fact, I am not seeing really any >> improvement. I am not sure what is wrong. Should I just test >> xen-unstable-tip+newest_patch and see where we stand? >> >> > > Yes, please. You shouldn''t have observed any performance difference > between 11225 and 11229 because the changeset 11226 did not enable the > global bit.OK, then that would explain it :) I''ll run tip+ your latest patch. -Andrew Theurer _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel