Re: aio

[Linus Torvalds]

On Wed, 19 Dec 2001, David S. Miller wrote:
>
> Ok, TUX can do it.  Now list for me some server that really matters
> other than web and ftp?

Now now, that's unfair. We should be able to do it in user space.

I think the question you _should_ be lobbying at Ben and the other aio
people is how the aio stuff could do zero-copy from disk cache to the
network, ie do the things that Tux does internally where it does
nonblocking reads from disk ad then sends them out non-blocking to the
network without havign to copy the data _or_ have to use extremely
expensive TLB mapping tricks to get at it..

Ie tie the "sendfile" and "aio" threads together, and ask Ben if we can do
aio-sendfile and have thousands of asynchronous sendfiles going on at the
same time, like Tux can do. And if not, then why not? Missing or bad
interfaces?

Ben? Doing user-space IO is all well and good, but that extra copy and TLB
stuff kills you. Tell us how to do it ;)

		Linus