Re: atomics: document that linux expects certain atomic behaviourfrom unsigned long

From: Alan Cox
Date: Mon Jan 05 2009 - 06:24:25 EST


> Pretty much everywhere that uses RCU for example does so using atomic pointer
> loads and stores. The nastiest issue IMO actually is reloading the value
> through the pointer even if it isn't explicitly dereferenced. RCU gets this
> right with ACCESS_ONCE. Probably a lot of code using basic types does not.
> x86 atomic_read maybe should be using ACCESS_ONCE too...

I'm pretty sure it should. gcc makes no guarantees about not being clever
with accesses.

Alan
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