Re: [RFC][PATCH 5/5] PM / Domains: Add default power off governor function

From: Rafael J. Wysocki
Date: Thu Sep 01 2011 - 18:09:26 EST


Hi,

On Thursday, September 01, 2011, Jean Pihet wrote:
> Rafael,
>
> On Wed, Aug 31, 2011 at 12:22 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >
> > Add a function deciding whether or not a given PM domain should
> > be powered off on the basis of that domain's devices' PM QoS
> > constraints.
> >
> > ---
> > drivers/base/power/domain_governor.c | 96 +++++++++++++++++++++++++++++++++++
> > include/linux/pm_domain.h | 7 ++
> > 2 files changed, 103 insertions(+)
> >
> > Index: linux/include/linux/pm_domain.h
> > ===================================================================
> > --- linux.orig/include/linux/pm_domain.h
> > +++ linux/include/linux/pm_domain.h
> > @@ -49,6 +49,10 @@ struct generic_pm_domain {
> > int (*start_device)(struct device *dev);
> > int (*stop_device)(struct device *dev);
> > bool (*active_wakeup)(struct device *dev);
> > + ktime_t power_off_latency;
> > + ktime_t power_on_latency;
> > + s64 break_even_ns;
> > + s64 min_delta_ns;
> How are those values populated?

I'm not sure. There are a few possible ways to do that, but I simply
don't know which one is going to be the most useful. That's one of
the reasons why patches [4-5/5] are RFCs.

> Is there a mechanism that dynamically updates the values?

Obviously not at the moment.

Thanks,
Rafael
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