Date: Fri, 25 Jun 1999 11:40:03 -0700 (PDT) From: Thomas Schuerger <schuerge@wjpserver.CS.Uni-SB.DE> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/12381: Bad scheduling in FreeBSD Message-ID: <199906251840.LAA34516@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR kern/12381; it has been noted by GNATS. From: Thomas Schuerger <schuerge@wjpserver.CS.Uni-SB.DE> To: Sheldon Hearn <sheldonh@uunet.co.za> Cc: freebsd-gnats-submit@freebsd.org Subject: Re: kern/12381: Bad scheduling in FreeBSD Date: Fri, 25 Jun 1999 20:35:29 +0200 (MET DST) > Having gone over this conversation a few times, I think I understand why > we're not connecting. You're coming from the perspective of someone who > wants processes nice'd to 20 to get out of the way of compute-bound > processes at nice <20. > > I'm coming from the perspective of someone who thinks FreeBSD does a > good job of sharing resources amongst multiple processes. The problem is > that it's exactly this that you're complaining about. It's the fact that > FreeBSD distributes CPU amongst processes using priority weightings and > decaying load average that's upsetting you. > > Basically, you want renice 20 pid to cause the affected pid to be > allowed as close to no CPU time as possible while there are > compute-bound processes at nice <20 running. > > Is this right? Yes, that's what I meant by bad scheduling. I think the nice-level only has a very minor effect in FreeBSD, which is not what I expect in a Unix environment. What it means is that there is no possibility to really run processes "in the background", e.g. sort of in the "spare time" of the CPU (these processes still should become active every now and then when more important processes are running, completely cutting them off would not be what I'd want). Something like an exponential drop off with increasing nice-levels would be fine, for example. Ciao, Thomas. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199906251840.LAA34516>