Re: [patch 3/3] tick: Annotate tick_do_timer_cpu data races

From: Thomas Gleixner
Date: Wed Dec 16 2020 - 16:24:40 EST


On Wed, Dec 16 2020 at 13:19, Paul E. McKenney wrote:
> On Wed, Dec 16, 2020 at 01:27:43AM +0100, Thomas Gleixner wrote:
>> So my intent was to document that this code does not care about anything
>> else than what I'd consider to be plain compiler bugs.
>>
>> My conclusion might be wrong as usual :)
>
> Given that there is no optimization potential, then the main reason to use
> data_race() instead of *_ONCE() is to prevent KCSAN from considering the
> accesses when looking for data races. But that is mostly for debugging
> accesses, in cases when these accesses are not really part of the
> concurrent algorithm.
>
> So if I understand the situation correctly, I would be using *ONCE().

Could this be spelled out somewhere in Documentation/ please?

Thanks,

tglx