From owner-freebsd-small Thu Jul 20 9:32: 9 2000 Delivered-To: freebsd-small@freebsd.org Received: from mail3.iadfw.net (mail3.iadfw.net [209.196.123.3]) by hub.freebsd.org (Postfix) with SMTP id E8C9037B946 for ; Thu, 20 Jul 2000 09:32:05 -0700 (PDT) (envelope-from karl@NeoSoft.com) Received: from NeoSoft.com from [209.44.243.145] by mail3.iadfw.net (/\##/\ Smail3.1.30.16 #30.4) with esmtp for sender: id ; Thu, 20 Jul 2000 11:32:24 -0500 (CDT) Message-ID: <39771F49.527C9E12@NeoSoft.com> Date: Thu, 20 Jul 2000 10:48:28 -0500 From: Karl Lehenbauer Organization: procplace.com, inc. - tcl trainers X-Mailer: Mozilla 4.7 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: freebsd-small@FreeBSD.ORG Subject: Re: Real Time FreeBSD ?? References: <3976A75D.9935.2F629B@localhost> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-small@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG There is *some* realtime stuff in FreeBSD. Check out rtprio(1) and rtprio(2). "A realtime process can only be preempted by a process of equal or higher priority, or by an interrupt." Also check out posix1b(9), which documents kernel options for posix priority scheduling. Also the asynchronous I/O operations aio_write(2), aio_read(2) and friends support posix prioritized I/O. There is a warning in one of the pages that FreeBSD can't guarantee it won't take a page fault on a realtime process. Also, system calls are not preemptable. -- Karl Lehenbauer employee #0 procplace.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message