george (11/09/82)
berkeley 4.1 seems to automatically renice processes to 4 after they have run for a certain length of time (~ 12 minutes). i thought it was the line in setpri() commented 'nice 4' but that doesn't seem to have anything to do with cpu time usage. it would nice if it was a constant somewhere but it doesn't seem to be that either. any help would be greatly appreciated.
chris.umcp-cs@Udel-Relay@sri-unix (11/19/82)
From: Chris Torek <chris.umcp-cs@Udel-Relay> Date: 15 Nov 82 01:46:31 EST (Mon) That's in "clock.c". If CPU usage goes too high, and the process isn't owned by UID 0, and the processes current nice is 0, it gets put at four. Interestingly, you can always "renice" it to one, and it stays there. (We have a modified renice here that lets anyone renice his own processes to nonnegative values.)
rlb@Purdue@sri-unix (11/22/82)
From: Bob Brown <rlb@Purdue> Date: 19 Nov 1982 00:27:04-EST We felt that the automatic renicing of processes by the kernel was slightly bogus. All it did was clog up the proc table with alot of pig processes (big troff, NA stuff, simulations) and just degrade the system as much as if they all just ran to completion. The code in clock.c was the first thing we yanked out of 4.1BSD. It especially caused problems here because we serialize troffs...if one got reniced, the queue of batched jobs behind it would get longer and longer and longer and eventually we were faced with overnight turnaround on troffs. Bob Brown Purdue-CS