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