On Sun, Mar 29, 2009 at 03:03:28PM +0300, Avi Kivity wrote: > Joerg Roedel wrote: >> On Sat, Mar 28, 2009 at 06:40:08PM -0300, Marcelo Tosatti wrote: >> >>> On Fri, Mar 27, 2009 at 03:31:52PM +0100, Joerg Roedel wrote: >>> >>>> Hi, >>>> >>>> this patchset extends the KVM MMU implementation to support 1GB pages as >>>> supported by AMD family 16 processors. These patches enable support for >>>> 1 GB pages with Nested Paging. Support for these pages in the shadow >>>> paging code was also developed but does not run stable yet. The patch >>>> for shadow-paging support is not included in this series and will be >>>> sent out seperatly. >>>> >>> Looks generally sane. I'm not sure its even worthwhile to support >>> GBpages with softmmu, because the chance of finding an area without >>> shadowed (write protected) pages is much smaller than with 2MB pages. >>> >> >> Thanks for your review. >> >> The idea behind GB pages in softmmu code was to provide GB pages to the >> guest even if hardware does not support it. This would work better with >> live migration (Only case where we wouldn't have gbpages then would be >> vmx with ept enabled). >> >> >>> Have any numbers to share? >>> >> >> No numbers I fully trust by now. I measured a 32% improvement in >> kernbench using nested pages backed with gb pages. I will do some more >> measurements and share some more solid numbers. >> >> > > Compared to 2M pages? But we're already close to native here. Yes, thats why I don't trust those numbers. I'll find out what went wrong and provide more solid numbers. Joerg -- 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
