From owner-freebsd-hackers Wed Jul 26 14:35:26 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.11/8.6.6) id OAA23625 for hackers-outgoing; Wed, 26 Jul 1995 14:35:26 -0700 Received: from cs.weber.edu (cs.weber.edu [137.190.16.16]) by freefall.cdrom.com (8.6.11/8.6.6) with SMTP id OAA23617 for ; Wed, 26 Jul 1995 14:35:24 -0700 Received: by cs.weber.edu (4.1/SMI-4.1.1) id AA23296; Wed, 26 Jul 95 15:09:58 MDT From: terry@cs.weber.edu (Terry Lambert) Message-Id: <9507262109.AA23296@cs.weber.edu> Subject: Re: Scheduling Algorithms (was: Re: panic in brelse() ... ) To: Marino.Ladavac@aut.alcatel.at Date: Wed, 26 Jul 95 15:09:58 MDT Cc: davidg@root.com, freebsd-hackers@freebsd.org In-Reply-To: <9507261747.AA02751@atuhc16.aut.alcatel.at> from "Marino.Ladavac@aut.alcatel.at" at Jul 26, 95 07:47:49 pm X-Mailer: ELM [version 2.4dev PL52] Sender: hackers-owner@freebsd.org Precedence: bulk [ ... a proposed linear reduction scheduling algorithm ... ] [ ... the BSD 4.4 algorithm ... ] [ ... the current FreeBSD modified BSD 4,.4 algorithm ... ] [ ... the Amiga time base promotion algorithm ... ] I think all of these algorithms miss the boat, if we are to be able to support RT scheduling and SMP scheduling. The main issue in both of these tasks that are on the table is a divorce of the ready-to-run state from the act of running the code. I think that this really implies seperate queues based on priority. It's necessary because multiple processes can be in the run state (for SMP, or even for kernel premption), and RT processes have to be able to be pigs as much as they want (if they are supported). Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.