On Thu, 2007-01-11 at 03:51 +0100, Ingo Molnar wrote: > * Rusty Russell <[EMAIL PROTECTED]> wrote: > > > > > Err no, this isn't true. See Documentation/lhype.txt or various blog > > > > entries on the subject 8) Both Xen and lhype get native syscall speeds > > > > (within measurement error). > > > > > > i was talking about 64-bit. (we dont really design for 32-bit anymore.) > [...] > > > > > I know that lhype uses Xen's ring 1 trick, but that's a 32-bit-only > > > thing. Also, can SYSENTER trap from guest userspace ring 3 into guest > > > kernelspace ring 1 on lhype? > > > > As I understand it, sysenter has to go to ring 0, and the reflection > > cost is way greater than the saving. > > so how can both "Xen and lhype get native syscall speeds (within > measurement error)", if it cannot use SYSENTER (it has to use int > $0x80), while a HVM kernel can?
Sorry, my mistake. I was measuring with a statically linked binary, which didn't use SYSENTER even when available 8( I've fixed virtbench now, and reflects this correctly. "syscalls almost as fast as poorly-implemented native syscalls"? Rusty. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
