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SubjectRe: [PATCH] "volatile considered harmful", take 3
On 5/11/07, Jonathan Corbet <corbet@lwn.net> wrote:
> Here's another version of the volatile document. Once again, I've tried
> to address all of the comments. There haven't really been any recent
> comments addressing the correctness of the document; people have been
> more concerned with how it's expressed. I'm glad to see files in
> Documentation/ held to a high standard of writing, but, unless somebody
> has a factual issue this time around I would like to declare Mission
> Accomplished and move on.

The document looks good, but whether:

> + - Pointers to data structures in coherent memory which might be modified
> + by I/O devices can, sometimes, legitimately be volatile. A ring buffer
> + used by a network adapter, where that adapter changes pointers to
> + indicate which descriptors have been processed, is an example of this
> + type of situation.

is a legitimate use case for volatile is still not clear to me (I
agree with Alan's
comment in a previous thread that this seems to be a case where a memory
barrier would be applicable^Wbetter, actually). I could be wrong here, so
would be nice if Peter explains why volatile is legitimate here.

Otherwise, it's fine with me.

Thanks,
Satyam
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