From owner-freebsd-hackers Sat Jun 6 02:39:40 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id CAA13270 for freebsd-hackers-outgoing; Sat, 6 Jun 1998 02:39:40 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from hda.hda.com (hda-bicnet.bicnet.net [208.220.66.37]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id CAA13248 for ; Sat, 6 Jun 1998 02:39:31 -0700 (PDT) (envelope-from dufault@hda.hda.com) Received: (from dufault@localhost) by hda.hda.com (8.8.5/8.8.5) id FAA09885; Sat, 6 Jun 1998 05:15:20 -0400 (EDT) From: Peter Dufault Message-Id: <199806060915.FAA09885@hda.hda.com> Subject: Re: [Fwd: FW: Adapting FreeBSD to be a RTOS] In-Reply-To: <35782846.ABD322C@whistle.com> from Julian Elischer at "Jun 5, 98 10:17:58 am" To: julian@whistle.com (Julian Elischer) Date: Sat, 6 Jun 1998 05:15:19 -0400 (EDT) Cc: hackers@FreeBSD.ORG, calebm@uspaceware.com 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-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Caleb R. Miller wrote: > > > > What I was looking for was a version of FreeBSD that had > > preemptive multitasking such that processes can run at > > different rates and get preempted if they don't complete > > within the assigned time. I did find a version of Linux > > that has a real-time kernel and that runs Linux as a process. > > I was wondering if anyone had done a similar thing with > > FreeBSD or had modified the FreeBSD kernel to do > > preemptive multitasking. There is nothing yet except "rtprio" / POSIX fixed priority scheduler. The processes will preempt, but the kernel is not reentrant. I don't know if this is what you want. I'm sketching out something for SMP or a time multiplexed kernel. Peter -- Peter Dufault (dufault@hda.com) Realtime development, Machine control, HD Associates, Inc. Safety critical systems, Agency approval To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message