sftp/scp performance testing

[Dan Kaminsky]

> Weird.  You need to run the patched sshd, ssh, and sftp programs.
> Running on localhost, your CPU utilization should be 100%.  You can verify
> this using vmstat or top.

A small note --

    My method for testing OpenSSH performance has been something along the
lines of:

    cat /dev/zero | ssh user at host "cat > /dev/null"

    and then monitoring network traffic using another tool.  Something like:

    cat /dev/zero | cpipe | ssh user at host "cat > /dev/null"

    would also work.  This method is useful because the zeronum generator is
faster than any randomizer, and it completely filters out disk I/O.

    Markus, a few words on OpenSSH profiling might be helpful? :-)

--Dan