Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262834AbVCJTQd (ORCPT ); Thu, 10 Mar 2005 14:16:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263053AbVCJTMz (ORCPT ); Thu, 10 Mar 2005 14:12:55 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:63648 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262778AbVCJTCq (ORCPT ); Thu, 10 Mar 2005 14:02:46 -0500 Subject: Re: Can I get 200M contiguous physical memory? From: Arjan van de Ven To: Nate Edel Cc: Jason Luo , linux-kernel@vger.kernel.org In-Reply-To: <00b701c525a3$128c2ac0$6a004b0a@charlemagne> References: <20050310081634.GA29516@taniwha.stupidest.org> <1110445030.6291.57.camel@laptopd505.fenrus.org> <00b701c525a3$128c2ac0$6a004b0a@charlemagne> Content-Type: text/plain Date: Thu, 10 Mar 2005 20:02:36 +0100 Message-Id: <1110481356.6291.133.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.0.2 (2.0.2-3) Content-Transfer-Encoding: 7bit X-Spam-Score: 4.1 (++++) X-Spam-Report: SpamAssassin version 2.63 on pentafluge.infradead.org summary: Content analysis details: (4.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.3 RCVD_NUMERIC_HELO Received: contains a numeric HELO 1.1 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] 2.5 RCVD_IN_DYNABLOCK RBL: Sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [80.57.133.107 listed in dnsbl.sorbs.net] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 970 Lines: 25 On Thu, 2005-03-10 at 10:57 -0800, Nate Edel wrote: > From: "Arjan van de Ven" > To: "Jason Luo" > >> A data acquisition card. In DMA mode, the card need 200M contiguous > >> memory for DMA. > > > > (or want to reserve memory at the boot commandline and then do really > > really evil hacks) > > Such as booting the machine with "mem=(real memory - 200)M" and then > just doing an ioremap of the top 200M of memory. > > It's not the most elegant way of doing things given that it requires > user intervention at boot time, but I'm not sure it counts as a "really > evil hack." it really gets evil if your machine has > 4Gb of ram... then things really go weird with this. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/