Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site decvax.UUCP
Path: utzoo!linus!decvax!larry
From: larry@decvax.UUCP (Larry Cohen)
Newsgroups: net.bugs.2bsd,net.bugs.uucp,net.unix-wizards
Subject: Re: 2.9 BSD uucico slowness
Message-ID: <84@decvax.UUCP>
Date: Sun, 7-Oct-84 11:40:34 EDT
Article-I.D.: decvax.84
Posted: Sun Oct  7 11:40:34 1984
Date-Received: Mon, 8-Oct-84 04:59:51 EDT
References: <359@cepu.UUCP>
Organization: DEC UNIX Engineering Group
Lines: 20

Here at decvax we will do anything to speed up uucico.
We also noticed that in the pk routines, several "reads"
were necessary to pull a packet off the network.  On the
average there were about 3 context switches per packet on
a 1200 baud line.  Of course this varied with the time of
day and speed of the line.  One "experiment" we tried was
to try a modified Berknet line discipline.  This line discipline
would read a specified number of characters and not return until
they all had arrived.  Internally it used circular queues. It
does not use clists at all.
The improvement was pretty good. 
I dont have the exact figures with me (I'm at home 4 months
after I ran the experiments) but It was something
in the ballpark of about 20 % improvement in overall throughput.
33 % reduction in context switches.  Less time was spent in the system,
and the user time was less also.  There was no reduction in performance
on 9600 baud lines.  I hope to try running on decvax before long.
						-Larry Cohen