Re: [PATCH -next] mm/page_counter: mark intentional data races

[Qian Cai]

> On Jan 29, 2020, at 4:06 AM, Marco Elver <elver@xxxxxxxxxx> wrote:
> 
> These should be using 'READ_ONCE' and 'WRITE_ONCE' for c->watermark.
> Store or load tearing would change the logic here, since the
> comparison might see garbage.

I originally thought that it probably does not matter because it is racy there by doing lockless access anyway. Another thread could change the value at anytime.

Now, I agree set it to a garbage due to a data race could be quite unpleasant there.