Re: [RFC v2 0/3][TESTS] LAB: Support for Legacy Application Boostergovernor - tests results

From: Lukasz Majewski
Date: Wed May 29 2013 - 09:46:07 EST


Hi Viresh,

> On 29 May 2013 12:39, Lukasz Majewski <l.majewski@xxxxxxxxxxx> wrote:
> > I also agree. Moreover, I think that there should be only one set of
> > "boost" sysfs entries either it is supported by HW (Intel) or SW
> > (ARM).
>
> Yes, you need to change acpi-cpufreq driver too to use this common
> infrastructure.

Ok, thanks for pointing out.

>
> > I can think of two "basic" one:
> > - max_turbo_freq (ro)
>
> This is surely per policy as two separate clusters can have separate
> values. And probably a better one would be scaling_boost_frequencies,
> that will list all boost frequencies.

Ok,

>
> > - turbo_mode/boost (rw)
>
> I am confused with these two names: boost and turbo.. Probably we
> should use a single name everywhere. Because acpi-cpufreq is already
> using boost, we might shift to that.
>
> > - /sys/devices/system/cpu/cpufreq/boost
>
> Obviously this one.
>
> > On the other hand first option would be used with systems, where
> > per-core (or core sets) frequency setting is possible (b.L,
> > Snapdragon S4)
>
> For now this feature would be enabled on all clusters and controlled
> by cpu/cpufreq/boost.

This will simplify considerably the driver code.

>
> > To sum up - the idea is as follow:
> >
> > 1. cpufreq_driver exports turbo_mode=1 when it supports overclocking
> > (this support can be hardcoded or read from device tree)
> >
> > 2. Then proper entries are exported to sysfs.
> >
> > 3. User via sysfs (at [*]) can enable/disable the feature on demand
>
> Bingo!!

Thanks for suggestions. I'm now working on a prototype code. I plan to
post it at the beginning of next week.

--
Best regards,

Lukasz Majewski

Samsung R&D Poland (SRPOL) | Linux Platform Group
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/