On Thu, Jul 31, 2008 at 11:03:39AM +0800, Herbert Xu wrote:

quoted

The maximum that splice will allow -- PIPE_BUFFERS * PAGE_SIZE.

I.e. the writes should be large enough.

Have you looked at the packet dump? Maybe it was being constrained
by the receiver/congestion windows.

The receiver seems to advertise a large enough window (700-ish KiB,
while the RTT is ~ 0.1 ms).  As to the congestion window, I had the
idea that it's not increasing beyond ~2-3 because the RTT is so low so
it doesn't need much data to fill the pipe, but I'm not a TCP expert.

I've put a tcpdump taken on the receiving end (192.168.42.10) here:

	http://www.wantstofly.org/~buytenh/dump.bz2

I'll be happy to try other things. :-)