On 09/25/2012 04:32 AM, Hao, Xudong wrote: > > > > btw, it is clear that long term the fpu will always be eagerly loaded, > > as hosts and guests (and hardware) are updated. At that time it will > > make sense to remove the lazy fpu code entirely. But maybe that time is > > here already, since exits are rare and so the guest has a lot of chance > > to use the fpu, so eager fpu saves the #NM vmexit. > > > > Can you check a kernel compile on a westmere system? If eager fpu is > > faster there than lazy fpu, we can just make the fpu always eager and > > remove quite a bit of code. > > > I remember westmere does not support Xsave, do you want performance of fxsave/fresotr ? Yes. If a westmere is fast enough then we can probably justify it. If you can run tests on Sandy/Ivy Bridge, even better. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- 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
