On Mon, 24 Dec 2007, Robert Watson wrote:
I've put up an updated tarball based on some recent changes here:
http://www.watson.org/~robert/freebsd/20071226-zcopybpf.tgz
Unfortunately, there was a problem with a change I made to the kernel check
for a userspace notification that a buffer was available via shared memory, so
I have updated the tarball. While there, I've made the following further
changes:
- bpf.4 has been updated to reflect the shared memory interface.
- I've eliminated the BPF_ZEROCOPY environmental variable in libpcap; libpcap
will try to use zero-copy BPF if it is compiled into the kernel and enabled.
- The kernel now has a net.bpf.zerocopy_enable sysctl, set to 1 by default,
which controls whether the kernel will allow new zero-copy BPF sessions to
be created.
- Memory barriers and atomic operations have been introduced on the shared
memory interface to improve correctness on platforms with weaker memory
consistency.
Robert N M Watson
Computer Laboratory
University of Cambridge
The main changes since this last drop are:
- BPF_ZERO_COPY environmental variable renamed to BPF_ZEROCOPY to match
kernel
option name.
- libpcap support for zero-copy BPF buffers reworked to avoid unconditional
call to select() for each buffer when there's already a pending buffer
available to use; in general, avoid system calls entirely when there's data
already waiting, only use system calls when there isn't a completed buffer
to work on next.
- Comments cleanup and some code cleanup.
- A README to provide a little more guidance on getting it working. :-)
You will need to "make clean ; make ; make install" in the modified libpcap
against, as the size of pcap_t has changed. In principle "make ; make
install" should DTRT, but it appears not to for me.
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]"
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
