Andre Oppermann writes:
>
> Could you run some bechmarks with the current MCLBYTES rounding
> and without it on 100Mbit 1.5kMTU and GigE with 9k MTU?
David Borman is totally right. Clipping the mss is really worth it,
especially with zero-copy sockets. Forget I said anything.
Here is som
David Borman writes:
> On the sending side, you'll tend to get your best performance when the
> socket buffer is a multiple of the amount of TCP data per packet, and
> the users writes are a multiple of the socket buffer. This keeps
> everything neatly aligned, minimizing the number of dat
On the sending side, you'll tend to get your best performance when the
socket buffer is a multiple of the amount of TCP data per packet, and
the users writes are a multiple of the socket buffer. This keeps
everything neatly aligned, minimizing the number of data copies that
need to be done, an
Andre Oppermann writes:
> When I was implementing the tcp_hostcache I reorganized/redid the
> tcp_mss() function and wondered about that too. I don't know if
> this rounding to MCLBYTES is still the right thing to do.
I have the feeling its something from ancient days on vaxes. ;)
> > Would
Andrew Gallatin wrote:
>
> For the case where the mtu is larger than MCLBYTES (2048), FreeBSD's
> TCP implementation restricts the mss to a multiple of MCLBYTES. This
> appears to have been inherited from 4.4BSD-lite.
>
> On adapters with 9000 byte jumbo frames, this limits the mss to 8192
> byt
