From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 21 Jun 2001 20:36:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 21 Jun 2001 20:36:21 -0400 Received: from pizda.ninka.net ([216.101.162.242]:48780 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Thu, 21 Jun 2001 20:36:11 -0400 From: "David S. Miller" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15154.37624.806402.350346@pizda.ninka.net> Date: Thu, 21 Jun 2001 17:36:08 -0700 (PDT) To: Mike Mackovitch Cc: Pete Zaitcev , root@chaos.analogic.com, linux-kernel@vger.kernel.org Subject: Re: Is it useful to support user level drivers In-Reply-To: <20010621165015.A11197@wacko.asicdesigners.com> In-Reply-To: <200106212206.f5LM6dK12282@devserv.devel.redhat.com> <15154.29468.215080.602628@pizda.ninka.net> <20010621160949.A10977@wacko.asicdesigners.com> <15154.33208.744328.463419@pizda.ninka.net> <20010621165015.A11197@wacko.asicdesigners.com> X-Mailer: VM 6.75 under 21.1 (patch 13) "Crater Lake" XEmacs Lucid Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mike Mackovitch writes: > On Thu, Jun 21, 2001 at 04:22:32PM -0700, David S. Miller wrote: > > What the heck is ULI then? I've actually read the assembly code for > > this back when I did my SGI internship. > > If my memory serves me correctly, I believe ULI was some > hacked up "user-level interrupt" feature. I have no idea > who (if anyone) used it, but it definitely wasn't used by > SGI's graphics drivers. Strange, because taking veritcal retrace interrupts directly in userspace was the first thing that came to my mind when I saw what ULI was doing. When IRIX optimizes something to the extreme, it is either for big-iron or graphics performance, very few exceptions exist :-) Later, David S. Miller davem@redhat.com