Path: utzoo!yunexus!maccs!dan From: dan@maccs.McMaster.CA (Dan Trottier) Newsgroups: comp.unix.questions Subject: Re: "Deep Background" applications Message-ID: <1303@maccs.McMaster.CA> Date: 8 Jul 88 12:43:16 GMT Article-I.D.: maccs.1303 References: <649@necis.UUCP> <29500025@urbsdc> <11019@cgl.ucsf.EDU> Reply-To: dan@maccs.UUCP (Dan Trottier) Distribution: na Organization: McMaster U., Hamilton, Ont., Can. Lines: 52 In article <11019@cgl.ucsf.EDU> seibel@hegel.mmwb.ucsf.edu.UUCP (George Seibel) writes: >In article <29500025@urbsdc> aglew@urbsdc.Urbana.Gould.COM writes: >] >][buncha stuff about Gould RT unix] >] >][More stuff deleted about needing differing levels of background execution >][priorities. > >Boy, would that be nice. We have a job mix that includes a healthy >fraction of multi-day cpu burners. We'd really like a way to make >those jobs butt out when someone wants to run a short (10 min-1 hr) >job. Does anyone know of an easy way to do something like this on >a bsd 4.[2-3] system? > Yes. Use the BSD command called nice(1) when starting up the job. The scenario is as follows: All jobs run at niceness 0 by default - This means they equally share the cpu with other level 0 jobs Jobs that run at niceness > 0 get less of the cpu - This means they will get less cpu cycles than jobs with lower niceness values Jobs that run with niceness < 0 get more of the cpu - This means they will get more cpu cycles than jobs with higher niceness values - Only ROOT can set niceness to less that zero So in order to run a job in the deep background and thus only execute when nothing else needs the cpu you should use a line like: nice 20 myjob & If you want another background job to capture more of the cpu then try: nice 10 anotherjob & Try several combinations of these nicenesses and see what the effects are. I found that a utility called "top" does a nice job of showing you the top X number of jobs running on the system and the resources they are using. Sorry about posting this but I think many people will be interested in this. dan -- A.I. - is a three toed sloth! | ...!uunet!mnetor!maccs!dan -- Official scrabble players dictionary -- | dan@mcmaster.BITNET