On Mon, Feb 22, 2016 at 12:27 PM, Viresh Kumar <[email protected]> wrote: > Hi, > > I am not really an intel-pstate driver guy, just wrote the patch based > on software-review of the stuff :) > > On 22-02-16, 10:17, Chen, Yu C wrote: >> IIRC, >> 1.HWP is hardwarely per-package, CPUs inside one package have one shared >> HWP. >> 2.Currently all the CPUs share the same HWP settings according to >> intel_pstate design. >> 3. The policy is per-cpu in intel_pstate driver.(policy->cpus only contains >> one cpu) >> >> So with this patch applied, it is likely CPUs may have different HWP >> settings? > > I think the hardware should be able to cope with that, and should be > selecting the frequency based on the highest frequency requested for > the same package. Otherwise, why should there be an option to supply > per-cpu settings ?
Right. I can easily imagine a use case in which someone may want to have different ranges for different CPUs. >> For example: >> CPU 0 belongs to package A with policy 0, and CPU 1 belongs to package B >> with policy 1, >> If you change the policy 0 from powersave to performance, then only CPU0 >> will update its >> min/max freq in HWP, however we should also update CPU 2's min/max in HWP >> settings? >> Plz correct me if I'm wrong.. > > I will let the official intel-pstate guys reply to that. My opinion is to do what your patch does until that proves to be a problem in practice. Thanks, Rafael
