Linus Torvalds (torvalds@osdl.org) on 5/16/06 wrote:
---------------------------
>Wink Saville (wink@saville.com) on 5/15/06 wrote:
>>
>>Doesn't Linux use messaging, I would say it does, for
>>instance in the block IO subsystem?
>
>Not really.
>
>Yes, the block IO subsystem can really be seen as a
>"message queue", but it's definitely not messages in the
>ukernel sense. It's very much a "pointers to data" model,
>where you wouldn't send the data as part of the message
>queue, you'd just have a pointer to it.
>

>
>Linus

I understand, it may not be a classical ukernel definition of messaging, but it fits my practical definition of messaging, which is simply a queue of *asynchronous* commands. There is no rule that states messaging precludes using pointers to data, it's the efficient asynchronous communication capability that is important.

So we see that messaging is used within the kernel and of course applications use the same techniques for the same reasons the kernel uses them. Therefore, it stands to reason that efficient asynchronous messaging should be one of the options for communicating between the kernel and applications.


Wink