Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!tektronix!ogcvax!omsvax!icalqa!hplabs!sri-unix!mike.rice@rand-relay From: mike.rice%rand-relay@sri-unix.UUCP Newsgroups: net.unix-wizards Subject: p_nice, and scheduling Message-ID: <3748@sri-arpa.UUCP> Date: Tue, 2-Aug-83 15:54:04 EDT Article-I.D.: sri-arpa.3748 Posted: Tue Aug 2 15:54:04 1983 Date-Received: Fri, 5-Aug-83 12:07:38 EDT Lines: 22 From: Mike.CaplingerWe are (unfortunately) in the position of running a lot of niced background compute-bound processes on our 4.1 11/750. Usually about 3 of these jobs are running at a nice of (usually) 4. Subjectively, it seems that these jobs are killing the system, in spite of their niceness. I theorize that it's because the system is constantly swapping them in and out as interactive jobs become ready to run and then wait for input again. Exactly what effect does nice have in the scheduler? I've looked at the code, but it isn't immediately obvious. Why did UCB change the default nice (10 in /bin/nice) to 4 in the builtin nice in the Cshell? If I change the Cshell default back to 10, will that help, hurt, or make any difference? If it helps, the machine config is a 750 with FPA, dual Unibus, 1 ra81, and 4 Meg of memory. The average size of the background processes is about 1 Meg, sometimes higher. Reply to me at mike.rice@rand-relay, and I will summarize to the net. Thanks much, everybody.