Larry McVoy wrote:
On Tue, Oct 02, 2007 at 06:52:54PM +0800, Herbert Xu wrote:
One of my clients also has gigabit so I played around with just that
one and it (itanium running hpux w/ broadcom gigabit) can push the load
as well. One weird thing is that it is dependent on the direction the
data is flowing. If the hp is sending then I get 46MB/sec, if linux is
sending then I get 18MB/sec. Weird. Linux is debian, running
First of all check the CPU load on both sides to see if either
of them is saturating. If the CPU's fine then look at the tcpdump
output to see if both receivers are using the same window settings.
tcpdump is a good idea, take a look at this. The window starts out
at 46 and never opens up in my test case, but in the rsh case it
starts out the same but does open up. Ideas?
(Binary tcpdumps are always better than ascii.)
The window on the sender (linux box) starts at 46. It doesn't open up,
but it's not receiving data so it doesn't matter, and you don't expect
it to. The HP box always announces a window of 32768.
Looks like you have TSO enabled. Does it behave differently if it's
disabled? I think Rick Jones is on to something with the HP ack
avoidance. Looks like a pretty low ack ratio, and it might not be
interacting well with TSO, especially at such a small window size.
-John
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
