From owner-freebsd-questions@FreeBSD.ORG Mon Nov 13 13:28:01 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9155816A403 for ; Mon, 13 Nov 2006 13:28:01 +0000 (UTC) (envelope-from g9471029@pu.edu.tw) Received: from mail.pu.edu.tw (eva.pu.edu.tw [140.128.5.28]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3C3E543D62 for ; Mon, 13 Nov 2006 13:28:01 +0000 (GMT) (envelope-from g9471029@pu.edu.tw) Received: from judea ([140.128.5.27]) by eli.pu.edu.tw (Sun Java System Messaging Server 6.2-3.04 (built Jul 15 2005)) with ESMTPA id <0J8O00J0Q808M700@eli.pu.edu.tw> for freebsd-questions@freebsd.org; Mon, 13 Nov 2006 21:26:33 +0800 (CST) Date: Mon, 13 Nov 2006 21:27:58 +0800 (CST) From: shin_ta To: freebsd-questions@freebsd.org Message-id: <15138958.7381163424479193.JavaMail.root@judea> MIME-version: 1.0 X-Mailman-Approved-At: Mon, 13 Nov 2006 13:48:39 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: help X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Nov 2006 13:28:01 -0000 I have some questions about the design and implementation of the FreeBSD op= erating system 1. FreeBSD used System call, Hardware interrupt, Hardware trap, an= d Software-initiated trap to entry into the system kernel. What is the deta= iled operation and why FreeBSD design by this way? =20 2. In FreeBSD 5.2, interrupt has its own context stack, what are t= he influences to each aspect of the operating system?(like bottom half of k= ernel, top half of kernel =E2=80=A6) =20 3. What is the basic function of the signal? Which main data struc= tures are about signal? Which procedures are related in signal? =20 4. Why signal handler routine design in user-level but not in kern= el-level? =20 5. After the system call completes, the system-call exit code firs= t checks for a posted signal, after checking for posted signals, the system= -call exit code checks to see whether any process has a priority higher tha= n that of the currently running one. Why FreeBSD do this check at this time= ? =20 6. The ULE scheduler was developed as part of the overhaul of Free= BSD to support SMP. Why the ULE scheduler relatively suitable for the SMP s= ystem than 4.4BSD timeshareing scheduler. =20 7. FreeBSD uses pager to manage the memory. Different memory objec= ts have different pager to deal with. Why FreeBSD designed by this way?=