Re: [PATCH 2/4] thermal: intel: hfi: Tune the HFI thermal netlink event delay via debugfs

From: Ricardo Neri
Date: Tue Apr 30 2024 - 20:53:08 EST


On Tue, Apr 30, 2024 at 04:52:52AM +0000, Zhang, Rui wrote:
> On Mon, 2024-04-29 at 16:41 -0700, Ricardo Neri wrote:
> > THe delay between an HFI interrupt and its corresponding thermal
>
> s/THe/The

Ah, I read the changelog 1000 times and still I misse this. Thanks!

>
> > netlink
> > event has so far been hard-coded to CONFIG_HZ jiffies. This may not
> > suit
> > the needs of all hardware configurations or listeners of events.
> >
> > If the update delay is too long, much of the information of
> > consecutive
> > hardware updates will be lost as the HFI delayed workqueue posts a
> > new
> > thermal netlink event only when there are no previous pending events.
> > If
> > the delay is too short, multiple, events may overwhelm listeners.
> >
> > Listeners are better placed to determine the delay of events. They
> > know how
> > quickly they can act on them effectively. They may also want to
> > experiment
> > with different values.
> >
> > Start a debugfs interface to tune the notification delay.
>
> Why this is implemented as debugfs rather than a module param?

Implementing as module param would require more work. In its current form,
intel_hfi is not a module. Its entry points are device_initcall()
(via therm_throt.c) and CPU hotplug.

I can look into implementing as a module param if folks think its a
better solution.