From owner-freebsd-hackers@FreeBSD.ORG Thu Jan 29 12:12:10 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 508D416A4CE for ; Thu, 29 Jan 2004 12:12:10 -0800 (PST) Received: from mail.spinnakernet.com (mail.spinnakernet.com [141.151.129.90]) by mx1.FreeBSD.org (Postfix) with ESMTP id 80B7443D2D for ; Thu, 29 Jan 2004 12:12:06 -0800 (PST) (envelope-from schellap@spinnakernet.com) Received: from spinnakernet.com (schellap-pc.spinnakernet.com [10.98.17.130]) by mail.spinnakernet.com (8.11.0/8.11.0) with ESMTP id i0TKC4u20861 for ; Thu, 29 Jan 2004 15:12:05 -0500 Message-ID: <40196875.1050307@spinnakernet.com> Date: Thu, 29 Jan 2004 15:09:25 -0500 From: Sridhar Chellappa User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.9) Gecko/20020408 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: Kernel Virtual Address Space X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Jan 2004 20:12:10 -0000 As part of the Bootup sequence, I see create_pagetables allocate only 30 Pages for Page Table entries in non-PAE mode and 120 pages in PAE mode. Does this mean that all the kernel mode entities get only 4 * 30 * 1024 * 1024 = 120 MB worth of Address Space ? Can I tune the kernel virtual address space by just changing the "NKPT" define in pmap.h ? Also, I heard that the BSD kernel(atleast from 5.1 onward) itself is pre-emptible and none of the kernel threads have a cpu affinity. How do I change the behaviour to make the kernel non-preemptible and tie kernel-threads to a particular CPU ? Sridhar.