From owner-freebsd-smp Sat Jan 22 18:59:24 2000 Delivered-To: freebsd-smp@freebsd.org Received: from rmx01.mail.com (rmx01.mail.com [165.251.32.149]) by hub.freebsd.org (Postfix) with ESMTP id 7C8AC15518 for ; Sat, 22 Jan 2000 18:59:16 -0800 (PST) (envelope-from scip7050@programmer.net) Received: from weba1.iname.net (weba1.iname.net [165.251.4.11]) by rmx01.mail.com (8.9.1/8.9.1) with ESMTP id VAA15693 for ; Sat, 22 Jan 2000 21:57:43 -0500 (EST) From: scip7050@programmer.net Received: (from root@localhost) by weba1.iname.net (8.9.1a/8.9.2.Alpha2) id VAA11358; Sat, 22 Jan 2000 21:57:43 -0500 (EST) MIME-Version: 1.0 Message-Id: <0001222157425P.27824@weba1.iname.net> Date: Sat, 22 Jan 2000 21:57:42 -0500 (EST) Content-Type: Text/Plain Content-Transfer-Encoding: 7bit To: smp@FreeBSD.org Subject: kernel thread issue Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Hi! I have some questions which I would like some kernel hackers could answer me. First, Why kernel thread cannot be spawned out for SMP case? The comment written in kern_fork.c said that "cannot have same PTD on both cpus, the PTD needs to be move out of PTmap and be per-process". Could anyone explain on this comment? Second, As I know that most kernel design to support kernel thread, will have to explicitly define another 'thread' data structure and try to put scheduling related information and hardware PCB and others to the thread structure. It seems that if the kernel is designed in this way to support the kernel thread, it makes things more explicitly defned. For instance, Solaris 2.x can even use the kernel thread to schedule interrupt handler in certain case. Hence it makes the kernel fully preemptible. The question is what will be the impact to the kernel if thread data structure is added in and used as the fundamental active scheduling objects? Thanks. Regards, NgCW ---------------------------------------------------------------- Get your free email from AltaVista at http://altavista.iname.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message