From owner-freebsd-hackers Thu Jul 1 17: 1:51 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from implode.root.com (root.com [209.102.106.178]) by hub.freebsd.org (Postfix) with ESMTP id 148CA15363 for ; Thu, 1 Jul 1999 17:01:47 -0700 (PDT) (envelope-from root@implode.root.com) Received: from implode.root.com (localhost [127.0.0.1]) by implode.root.com (8.8.8/8.8.5) with ESMTP id RAA07819; Thu, 1 Jul 1999 17:01:58 -0700 (PDT) Message-Id: <199907020001.RAA07819@implode.root.com> To: Zhihui Zhang Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: reason for slow user-user memory copy In-reply-to: Your message of "Thu, 01 Jul 1999 19:36:10 EDT." From: David Greenman Reply-To: dg@root.com Date: Thu, 01 Jul 1999 17:01:58 -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >> If the mapping is being done via a device mapping, then the region will >> be marked non-cacheable. > >I remember that he said he created a character device /dev/tulip to >represent the network card. Actually, his work borrowed a lot from the >Cornell U-Net project (now the basis of VIA?). Can we change the >corresponding page table (directory) entries to be cacheable as needed? You'd have to modify the kernel - specifically pmap_mapdev(). Note that the above behavior is only true for older versions of FreeBSD (pre-2.2). If you're having this problem within a newer version of FreeBSD, then it's probably something else causing it. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org Creator of high-performance Internet servers - http://www.terasolutions.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message