Re: [PATCH v3] clocksource: Scale the max retry number of watchdog read according to CPU numbers

[Waiman Long]

On 2/19/24 09:37, Feng Tang wrote:
> Hi Thomas,
>
> On Mon, Feb 19, 2024 at 12:32:05PM +0100, Thomas Gleixner wrote:
> > On Mon, Jan 29 2024 at 21:45, Feng Tang wrote:
> > > +static inline long clocksource_max_watchdog_read_retries(void)
> > > +{
> > > +	long max_retries = max_cswd_read_retries;
> > > +
> > > +	if (max_cswd_read_retries <= 0) {
> > > +		/* santity check for user input value */
> > > +		if (max_cswd_read_retries != -1)
> > > +			pr_warn_once("max_cswd_read_retries was set with an invalid number: %ld\n",
> > > +				max_cswd_read_retries);
> > > +
> > > +		max_retries = ilog2(num_online_cpus()) + 1;
> > I'm getting tired of these knobs and the horrors behind them. Why not
> > simply doing the obvious:
> >
> >         retries = ilog2(num_online_cpus()) + 1;
> >
> > and remove the knob alltogether?
> Thanks for the suggestion! Yes, this makes sense to me. IIUC, the
> 'max_cswd_read_retries' was introduced mainly to cover different
> platforms' requirement, which could now be covered by the new
> self-adaptive number.
>
> If there is no concern from other developers, I will send a new
> version in this direction.

I see no problem simplifying it.

Cheers,
Longman