On Wed, 5 Dec 2007, Robert Watson wrote:
On Wed, 5 Dec 2007, Vlad GALU wrote:
I would like to try the aforementioned patches too. Can you please point me
to a link?
You can download our experimental tarball from here:
http://www.watson.org/~robert/freebsd/20071103-zcopybpf.tgz
You can find a BSDCan quick talk on the topic here:
http://www.watson.org/~robert/freebsd/2007bsdcan/20070517-devsummit-zerocopybpf.pdf
I've had several reports of significantly improved packet capture rates at
high speeds with it, but it's not yet in the tree because we feel it needs
more evaluation and review. I hope to ship some form of zero-copy BPF
buffer support in FreeBSD 8, and possibly even MFC it. Any feedback you
might have would be most helpful.
Having sent you the patch, I should have let you know that you'll need to:
- Add options BPF_ZEROCOPY to your kernel configuration to enable the
zero-copy buffering mode.
- Make sure the kernel and libpcap are rebuild following the application of
the patch and dropping in the tarball.
- setenv BPF_ZERO_COPY before running tcpdump or other BPF-based tools to
enable the zero-copy buffer mode.
The patch includes both kernel changes (abstract the buffer model, add a new
buffer model) and user space changes (updated libpcap to speak the new model,
selected right now with the environmental variable). Presumably if merged,
zero-copy BPF buffers would be used by default via libpcap if present in the
kernel, but right now this is all for evaluation purposes.
Robert N M Watson
Computer Laboratory
University of Cambridge
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
