On 2017/8/8 15:41, Cornelia Huck wrote: > On Tue, 8 Aug 2017 12:05:31 +0800 > "Longpeng(Mike)" <longpeng2@xxxxxxxxxx> wrote: > >> This is a simple optimization for kvm_vcpu_on_spin, the >> main idea is described in patch-1's commit msg. > > I think this generally looks good now. > >> >> I did some tests base on the RFC version, the result shows >> that it can improves the performance slightly. > > Did you re-run tests on this version? Hi Cornelia, I didn't re-run tests on V2. But the major difference between RFC and V2 is that V2 only cache result for X86 (s390/arm needn't) and V2 saves a expensive operation ( 440-1400 cycles on my test machine ) for X86/VMX. So I think V2's performance is at least the same as RFC or even slightly better. :) > > I would also like to see some s390 numbers; unfortunately I only have a > z/VM environment and any performance numbers would be nearly useless > there. Maybe somebody within IBM with a better setup can run a quick > test? > > . > -- Regards, Longpeng(Mike)
