zero-copy TCP fileserving

Bjorn Wesen (bjorn@sparta.lu.se)
Wed, 2 Jun 1999 17:18:11 +0200 (MET DST)


Speaking of shortcuts, what is the status of some sort of direct
page -> skb TCP sending ?

What I mean is, when tcp does a sendmsg, it shouldn't need to copy the
actual data into the skbuf, but merely the headers, and remember a ptr to
the data area (which would have to be locked down until the fragment is
acked or the connection breaks, of course). Then the network driver could
(if it supports s/g DMA) send the headers + data directly from memory.

Combine this with mmap() and you have a zero-copy fileserver from userland
without any major hacks.

Optimizing reception is harder due to not knowing the length of received
packets etc, I guess.

AFAIK this functionality is not in place in 2.2, but are there any people
here who has hacked it or any on-going projects doing it for 2.3 ?

/Bjorn

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/