Messages in this thread | | | Date | Sat, 12 May 2007 08:51:24 +0530 | From | "Satyam Sharma" <> | Subject | Re: [PATCH] "volatile considered harmful", take 3 |
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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.
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