Re: [PATCH 2/2] powerpc: implement arch_scale_smt_power for Power7

Joel Schopp
2010-01-25T17:51:13Z

Benjamin Herrenschmidt wrote:
> On Wed, 2010-01-20 at 16:09 -0600, Joel Schopp wrote:
>
>> I can turn that into a conditional branch (case statement) with a shift
>> for the common 1,2,4 cases which should cover all procs available today
>> falling back to a divide for any theoretical future processors that do
>> other numbers of threads.
>>
>
> Look at the cputhreads.h implementation ... Today we only support
> power-of-two numbers of threads.
>
I've run 3 threads using cpu hotplug to offline 1 of the 4. It's
certainly a stupid idea, but there you go.