From owner-freebsd-realtime Wed Mar 11 09:08:06 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id JAA08914 for freebsd-realtime-outgoing; Wed, 11 Mar 1998 09:08:06 -0800 (PST) (envelope-from owner-freebsd-realtime@FreeBSD.ORG) Received: from Ilsa.StevesCafe.com (Ilsa.StevesCafe.com [205.168.119.129]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id JAA08841 for ; Wed, 11 Mar 1998 09:07:59 -0800 (PST) (envelope-from fbsd@Ilsa.StevesCafe.com) Received: from Ilsa.StevesCafe.com (localhost [127.0.0.1]) by Ilsa.StevesCafe.com (8.8.7/8.8.5) with ESMTP id KAA10990; Wed, 11 Mar 1998 10:07:30 -0700 (MST) Message-Id: <199803111707.KAA10990@Ilsa.StevesCafe.com> X-Mailer: exmh version 2.0gamma 1/27/96 From: Steve Passe To: Peter Dufault cc: rich@immrc1.Eng.McMaster.CA (Richard Teltz), realtime@FreeBSD.ORG Subject: Re: threads questions In-reply-to: Your message of "Wed, 11 Mar 1998 11:52:25 EST." <199803111652.LAA25788@hda.hda.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 11 Mar 1998 10:07:30 -0700 Sender: owner-freebsd-realtime@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi, > You still have the many issues of the non-reentrancy of the kernel, > etc, that make FreeBSD inappropriate for most serious uses. If I > had the time I'd follow this route: > ... I am trying to use 2.2.5 for soft realtime in a project, including the use of threads. One trick we are experimenting with is the use of NMI on our custom hardware. When the hardware needs service it (optionally) asserts both an NMI and a regular INT. The NMI code jumps in and grabs timely info from the hardware, storing it away with the 64bit CPU timestamp, then exits. The regular INT then comes along later and does the higher level things that require reentrancy and critical region protection of the kernel proper. I've been toying around with the idea of setting up a web page to support RT and possibly threads, as a place where we could all gather our experiences in this area. Any interest out there in contributing info for such a page? -- Steve Passe | powered by smp@csn.net | Symmetric MultiProcessor FreeBSD To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-realtime" in the body of the message