em(4) patch

[Sten Spans]

On Tue, 19 Apr 2005, Pyun YongHyeon wrote:

> On Thu, Apr 14, 2005 at 06:26:08PM +0900, To freebsd-sparc64 at freebsd.org wrote:
> >
> > I have a initial patch that make em(4) work on sparc64.
> > The patch seems to work but it may have uncovered bugs in it.
>
> Here is updated patch.
> http://www.kr.freebsd.org/~yongari/em.patch.0419
>
> The new patch includes jmg's suggestion and supports JUMBO frames.
> Though OpenBSD's aligment code works well I noticed it suffers
> from poor performance. So I used simple mbuf prepend method which
> is slightly faster than that of OpenBSD's code. Of course, best
> performance would be obtained when JUMBO frame is not used at all. :-(

Great, thanks for looking into this.

I've tested the patch on an alpha (ds10) running 5.4-RC3,
with dev/em from current.

Some netperf results:

                    Recv   Send    Send
                    Socket Socket  Message  Elapsed
                    Size   Size    Size     Time     Throughput
                    bytes  bytes   bytes    secs.    10^6bits/sec
openbsd code in:    87380  32768  32768    10.01     415.38
openbsd code out:   65536  16384  16384    10.00     403.87
fbsd patch  in:     87380  32768  32768    10.01     409.02
fbsd patch out:     65536  16384  16384    10.00     464.78


Aka roughly comparable performance, and no crash :)

-- 
Sten Spans

"There is a crack in everything, that's how the light gets in."
Leonard Cohen - Anthem