From owner-freebsd-hackers Wed Jun 3 16:52:35 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA03353 for freebsd-hackers-outgoing; Wed, 3 Jun 1998 16:52:35 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from swing.ca.sandia.gov (swing.ca.sandia.gov [146.246.246.5]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id QAA03119 for ; Wed, 3 Jun 1998 16:52:06 -0700 (PDT) (envelope-from cc@swing.ca.sandia.gov) Received: from swing.ca.sandia.gov (localhost [127.0.0.1]) by swing.ca.sandia.gov (8.8.8/8.8.8) with ESMTP id LAA08485; Wed, 3 Jun 1998 11:52:37 -0500 (CDT) (envelope-from cc@swing.ca.sandia.gov) Message-Id: <199806031652.LAA08485@swing.ca.sandia.gov> X-Mailer: exmh version 2.0.2 2/24/98 To: dg@root.com cc: freebsd-hackers@FreeBSD.ORG Subject: Re: VM Questions In-reply-to: Your message of "Tue, 02 Jun 1998 20:35:34 PDT." <199806030335.UAA19842@implode.root.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 03 Jun 1998 11:52:37 -0500 From: "Chris Csanady" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >>First, I was wondering if it is possible given a physical address, >>to copy data to it from a virtual address. Or is a virtual mapping >>necessary? > > There must be a virtual mapping. > >>The other question is how may I map user pages into the kernel? I've >>looked through vm_map.c, and it seems that support for this is >>lacking. To get around this for now, I am attempting to use almost >>exclusively physical address--although am now sure how it will work >>out. > > vm_map.c isn't really the right place to look. A better place would be >physio/vmapbuf/vunmapbuf in kern_physio.c and vm_machdep.c. Thanks to all that have pointed me in the right direction wrt this type of thing. :) I think I should have enough info now to get things working properly now. I was kind of curious about one thing though--in vm_page.c, there is mention that vm_hold should only be used for temporary wiring. Is it really bad to use it often? I want to have the process wired anyways, so would this even matter? -Chris To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message