Re: [PATCH v8 08/25] timer: Rework idle logic

[Thomas Gleixner]

On Tue, Oct 10 2023 at 13:19, Frederic Weisbecker wrote:
> On Tue, Oct 10, 2023 at 12:15:09AM +0200, Thomas Gleixner wrote:
>> > +	base->is_idle = time_after(nextevt, basej + 1);
>> 
>> This is wrongly ordered. base->is_idle must be updated _after_
>> evaluating base->timers_pending because the below can change nextevt,
>> no?
>> 
>> > +	if (base->timers_pending) {
>> > +		/* If we missed a tick already, force 0 delta */
>> > +		if (time_before(nextevt, basej))
>> > +			nextevt = basej;
>> > +		expires = basem + (u64)(nextevt - basej) * TICK_NSEC;
>
> I suspect it doesn't matter in pratice: base->is_idle will remain false
> if it's before/equal jiffies.
>
> Still it hurts the eyes so I agree the re-ordering should happen here and
> this will even simplify a bit the next patch.

Right. Anna-Maria just pointed that out to me before, but we are all in
violent agreement that it sucks :)