Re: [linux-pm] [PATCH v4] PM: add statistics debugfs file for suspend to ram

[Greg KH <gregkh@suse.de>]

On Thu, Aug 11, 2011 at 01:22:56AM +0530, Mansoor, Illyas wrote:
> static pm_message_t pm_transition;
> > > >
> > > > @@ -464,8 +465,12 @@ void dpm_resume_noirq(pm_message_t state)
> > > >  		mutex_unlock(&dpm_list_mtx);
> > > >
> > > >  		error = device_resume_noirq(dev, state);
> > > > -		if (error)
> > > > +		if (error) {
> > > > +			suspend_stats.failed_resume_noirq++;
> > > > +			dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
> > > > +			dpm_save_failed_dev(dev_name(dev));
> > >
> > > Please make these statistics conditionally enabled, so on a production system
> > > If we need to disable these statistics code we should be able to do so.
> > 
> > Why, are they taking time or space that is needed for something else?
> > What's the downside here of just not always having this enabled?
> 
> Why have something that is not required/Used?

Because someone might need it and rebuilding a kernel isn't possible on
lots of devices.

> Its only useful if DEBUGFS is configured anyways

Almost all systems these days have debugfs enabled, so that's a moot
point.

greg k-h