Re: [PATCH] Display Intel Dynamic Acceleration feature in /proc/cpuinfo

Venki Pallipadi
2007-05-24T21:13:57Z

On Thu, May 24, 2007 at 05:01:04PM -0400, Dave Jones wrote:
> On Thu, May 24, 2007 at 01:55:13PM -0700, Andrew Morton wrote:
> > On Wed, 23 May 2007 15:46:37 -0700
> > Venki Pallipadi <venkatesh.pallipadi@intel.com> wrote:
> >
> > > Display Intel Dynamic Acceleration feature in /proc/cpuinfo. This feature
> > > will be enabled automatically by current acpi-cpufreq driver and cpufreq.
> >
> > So you're saying that the cpufreq code in Linus's tree aleady supports IDA?
> > If so, this is a 2.6.22 patch, isn't it?
>
> From my limited understanding[*], ida is the "We're single threaded,
> disable the 2nd core, and clock the first core faster" magic.
> It doesn't need code-changes, as its all done in hardware afaik.

IDA state will appear as a new highest freq P-state (P0) and when software
requests that frequency, hardware can provide a higher frequency than that
oppurtunistically and transparently.

The current cpufreq code will detect this new state and enter that state
when CPU is busy.

>
> identifying & exporting the flags on earlier kernels should be harmless,
> but not really 'mustfix'.
>

Agree with Dave that it is not a mustfix. As the patch is pretty harmless
would be nice to have in 2.6.22.

Thanks,
Venki