Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site rlgvax.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!rlgvax!guy From: guy@rlgvax.UUCP (Guy Harris) Newsgroups: net.unix-wizards,net.bugs.4bsd Subject: Re: automatic renice in 4.1 bsd? Message-ID: <190@rlgvax.UUCP> Date: Sat, 13-Oct-84 00:39:43 EDT Article-I.D.: rlgvax.190 Posted: Sat Oct 13 00:39:43 1984 Date-Received: Sun, 14-Oct-84 04:46:04 EDT References: <170@terak.UUCP> Distribution: net Organization: CCI Office Systems Group, Reston, VA Lines: 32 > We have started to notice a problem with some > people's login csh being reniced. Since we always > have a few processes running, these people's terminal > appears to be dead. > > By reniceing the csh to 0, the terminal becomes alive > again, and renice reports the old priority as 19. > > Is there some thing in 4.1 bsd that renices people when > the system load gets too high? In 4.2BSD, the following code appears in "kern_clock.c": /* * Check to see if process has accumulated * more than 10 minutes of user time. If so * reduce priority to give others a chance. */ if (p->p_uid && p->p_nice == NZERO && u.u_ru.ru_utime.tv_sec > 10 * 60) { p->p_nice = NZERO+4; (void) setpri(p); p->p_pri = p->p_usrpri; } so if a process accumulates enough CPU time, the system decides it's had enough favorable treatment and it's time to get tough with it. I seem to remember something like this also being in 4.1BSD, so that's what may be happening. Check "clock.c" in the kernel source. Guy Harris {seismo,ihnp4,allegra}!rlgvax!guy