Messages in this thread | | | Subject | Re: [PATCH V5] powercap/drivers/idle_injection: Add an idle injection framework | From | Daniel Lezcano <> | Date | Thu, 7 Jun 2018 11:09:13 +0200 |
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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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