Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!rutgers!mit-eddie!jbs From: jbs@mit-eddie.UUCP Newsgroups: comp.unix.questions,comp.unix.wizards Subject: nice values for different groups (suggestions wanted) Message-ID: <4231@mit-eddie.MIT.EDU> Date: Wed, 10-Dec-86 23:39:08 EST Article-I.D.: mit-eddi.4231 Posted: Wed Dec 10 23:39:08 1986 Date-Received: Sun, 14-Dec-86 09:16:53 EST Reply-To: jbs@eddie.MIT.EDU (Jeff Siegal) Distribution: world Organization: MIT, EE/CS Computer Facilities, Cambridge, MA Lines: 34 Summary: How much does one's nice value affect scheduler "preference" in allocating CPU Xref: watmath comp.unix.questions:302 comp.unix.wizards:321 The following applies to a 4.3BSD VAX: Recently, you may recall my having inquired about ways to have users be niced to different values without limiting them to a specific shell. I received a number of suggestions, but I didn't really like any of them, so I implemented my own "solution." My /bin/login now checks the file /etc/priorities for the group name or user name of the user logging in, and sets the user's priority to the priority found there. If both the user and group are found in the file, the priority listed for the user takes precedence. I'm willing to send out or post the changes if there is interest, and if someone convinces me that I won't be violating any license agreements or copyright laws by doing so. Anyway, now my question is, what are good nice values to use. What I want to achieve is giving significant preference to users in the higher groups when allocating CPU, without completely starving users in the lower groups. For example, if one user from each of two groups was logged in, running a job moderately heavy on the CPU (e.g. text formatter, C compiler, etc.), I'd like the "higher" user to get, say, twice as much CPU as the "lower" user. Similarly, if both were running a text editor on an otherwise moderately loaded system, I'd like the "higher" user to see response time better by maybe a factor of two. Right now, I have the values for each of three groups set at 0, 1, and 2, but I don't know if these values are sufficiently different to accomplish what I want, of if the magnitude of the priority difference is even significant. Jeff Siegal