From owner-freebsd-hackers Fri Jan 31 04:36:09 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id EAA21001 for hackers-outgoing; Fri, 31 Jan 1997 04:36:09 -0800 (PST) Received: from hda.hda.com (ip87-max1-fitch.ziplink.net [199.232.245.87]) by freefall.freebsd.org (8.8.5/8.8.5) with SMTP id EAA20990 for ; Fri, 31 Jan 1997 04:36:05 -0800 (PST) Received: (from dufault@localhost) by hda.hda.com (8.6.12/8.6.12) id HAA12655; Fri, 31 Jan 1997 07:30:50 -0500 From: Peter Dufault Message-Id: <199701311230.HAA12655@hda.hda.com> Subject: Re: Jukka Ukkonen: POSIX.4 - scheduler once more (as you requested) In-Reply-To: <14120.854650859@time.cdrom.com> from "Jordan K. Hubbard" at "Jan 30, 97 11:00:59 am" To: jkh@time.cdrom.com (Jordan K. Hubbard) Date: Fri, 31 Jan 1997 07:30:49 -0500 (EST) Cc: hackers@freebsd.org X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk One quick observation: > X * 5. The source code must be available for anyone who wishes to have it. Jukka has already heard this part: What do people think of packaging this up as a user library against an LKM'd pseudo /dev/realtime driver? I have the skeleton to do that. My reasoning is I'd like to be able to have different realtime facilities, for example, process migration to an attached embedded processor that would "fault" back as soon as you tried to do something in that environment. It also gives you a way to have realtime user or group protection. I realise that Jukka's work could always be the default soft-realtime behavior, but if done differently a single binary wouldn't run in both places. The hooks into the default kernel have to be kept well defined with that approach. A downside to this approach is that these won't be system calls. Peter -- Peter Dufault (dufault@hda.com) Realtime Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936