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

[Daniel Lezcano]

On 07/06/2018 10:49, Viresh Kumar wrote:
> 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
> readers.

Ok understood. Why would a compiler do this kind of things ?

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