Re: atomics: document that linux expects certain atomic behaviour from unsigned long

On Sat 2009-01-03 20:19:55, Alan Cox wrote:
> On Sat, 3 Jan 2009 13:44:00 +0100
> Pavel Machek <pavel <at> suse.cz> wrote:
> 
> > Linux relies on unsigned long to behave like atomic for read/write.
> 
> Actually it isn't that simple and this advice shouldn't be given IMHO.
> 
> unsigned long is not the same as atomic in several respects including
> ordering and caching of the result.

Ok... I keep seeing patches using int/long instead of atomic and
claiming that it is okay.

If it is okay and linux relies on it, it should be documented.

If it is not okay, I guess we should document it, too -- it seems to
be common mistake. 

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