Re: Linux Zero Copy

From: Nagendra Singh Tomar (
Date: Wed Aug 13 2003 - 23:17:57 EST

Thanx for ur reply. So this means that this Zero Copy can only be
used by senders who have to send data from a "file" that supports mmap. I
just can't fill a buffer in userland and expect it to be sent via Zero
Your pointer though clears all my confusions.


On Wed, 13 Aug 2003, Jamie Lokier wrote:

> Nagendra Singh Tomar wrote:
> > Code walkthru of Linux 2.4.18 kernel reveals that we do copy from user
> > space for both linear and nonlinear skbuffs. What is this zerocopy
> thing
> > then ?
> Take a look at the sendfile() system call. There is no user space
> data; it can do zerocopy from the page cache.
> -- Jamie

To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at