Nicolas,
On Thu, Jun 10 2021 at 14:59, Nicolas Saenz Julienne wrote:
please always Cc the relevant mailing lists and the maintainers.
MAINTAINERS exists for a reason.
> We need to efficiently check whether a timer base has no pending
> events.
'We need' is not a technical explanation. That's close to 'I want a pony'.
Please describe what you are trying to solve and why the existing
mechanisms are not good enough.
See Documentation/process/submitting-patches.rst
> So introduce a new variable in struct timer_base to do so.
The variable solves your problem? Interesting solution.
> base->next_expiry = bucket_expiry;
> base->next_expiry_recalc = false;
> +#ifdef CONFIG_PREEMPT_RT
> + base->pending = true;
> +#endif
What is RT specific about that?
> trigger_dyntick_cpu(base, timer);
> }
> }
> @@ -1598,6 +1602,9 @@ static unsigned long __next_timer_interrupt(struct timer_base *base)
> }
>
> base->next_expiry_recalc = false;
> +#ifdef CONFIG_PREEMPT_RT
> + base->pending = (next != base->clk + NEXT_TIMER_MAX_DELTA);
> +#endif
This lacks any information about the semantics of this flag:
- When is it valid and when not?
- What is the valid use case for this flag?
Summary of the supplied information: We need a flag, so we added one.
Sorry that's not sufficient.
Thanks,
tglx
