From owner-freebsd-arch Sun Oct 13 19:12:58 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2F5F937B401 for ; Sun, 13 Oct 2002 19:12:57 -0700 (PDT) Received: from softweyr.com (softweyr.com [65.88.244.127]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6E7A643EAC for ; Sun, 13 Oct 2002 19:12:56 -0700 (PDT) (envelope-from wes@softweyr.com) Received: from nextgig-10.access.nethere.net ([66.63.140.202] helo=softweyr.com) by softweyr.com with esmtp (Exim 3.35 #1) id 180uia-0006cY-00; Sun, 13 Oct 2002 20:12:29 -0600 Message-ID: <3DAA2AEC.EFF1C9F1@softweyr.com> Date: Sun, 13 Oct 2002 19:24:44 -0700 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.78 [en] (X11; U; Linux 2.4.2 i386) X-Accept-Language: en MIME-Version: 1.0 To: ticso@cicely.de Cc: "M. Warner Losh" , hch@infradead.org, dillon@apollo.backplane.com, vova@sw.ru, nate@root.org, arch@FreeBSD.org Subject: Re: Database indexes and ram References: <200210082051.g98KpjU1084793@apollo.backplane.com> <3DA4C271.37AACAA3@softweyr.com> <20021012135245.A16453@infradead.org> <20021012.150616.129769790.imp@bsdimp.com> <20021013103538.GG17920@cicely8.cicely.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Bernd Walter wrote: > > On Sat, Oct 12, 2002 at 03:06:16PM -0600, M. Warner Losh wrote: > > In message: <20021012135245.A16453@infradead.org> > > Christoph Hellwig writes: > > : On Wed, Oct 09, 2002 at 04:57:37PM -0700, Wes Peters wrote: > > : > Linux solved this problem by refusing to do it. The candidates for DMA > > : > transfers include skbufs and buffers from the disk buffer pool, both of > > : > which are allocated from the lowest 4GB of physical ram when using PAE > > : > mode. > > : > > : Umm, Linux _does_ DMA into any memory if the NIC/HBA/whatever supports > > : it. > > > > Unless the card is 64bit, it can't DMA past 4G. > > Shouldn't all modern pci chips support two 32bit word addresses. Yeah, right. Find me a 64-bit ATAPI controller... -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC wes@softweyr.com http://softweyr.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message