Re: [PATCH V5] powercap/drivers/idle_injection: Add an idle injection framework

From: Viresh Kumar
Date: Thu Jun 07 2018 - 04:49:32 EST

On 07-06-18, 10:46, Daniel Lezcano wrote:
> Yes, correct.
> But if we don't care about who wins to store to value, is there a risk
> of scramble variable if we just assign a value ?

Normally no, as the compiler wouldn't screw it up badly. But there is no rule
which stops the compiler from doing this:

idle_duration_ms = 5;
idle_duration_ms = -5;
idle_duration_ms = 0;
idle_duration_ms = <real-value-we-want-to-write>;

So we *must* use READ/WRITE_ONCE() to make sure garbage values aren't seen by