From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 21 May 2001 18:36:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 21 May 2001 18:36:09 -0400 Received: from [192.187.140.129] ([192.187.140.129]:51329 "EHLO paracel.com") by vger.kernel.org with ESMTP id ; Mon, 21 May 2001 18:36:02 -0400 From: "Christophe Beaumont" To: "Linux-Kernel" Subject: HUGE contiguous mem space with 2.4 Date: Mon, 21 May 2001 15:39:32 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi... I am facing an odd problem here. I have an application here that requires a HUGE physically contiguous memory area to be locked (yes, I have hardware DMA'ing in and out of that area, over the PCI bus). HUGE being like one Gig (could be more if needed...) I am trying to use the mem=1024M option at boot time (yes, the box has 2 Gigs of RAM) and then ioremap() from within my module. There I have a couple of issues: - if I use high_memory as is, I cannot remap any area (high_memory=f800:0000 ???) - if I use high_memory thru virt_to_phys, I can then remap... up to 64 Megs (maybe a little more, but for sure less than 128 Megs) (virt_to_phys(high_mem)=3800:0000) I tried with other values (like mem=250M 512M 1536M) and could NOT remap anything close to the whole amount of "reserved" memory (best case being with mem=256M I can remap 512M out of 1.75Gigs) I guess I am missing a point somewhere.... or have totally been "ignoring" some doc somewhere (alessandro could be the man for this one thing *-) ) [system is a dual P3 with 2 gigs of RAM, a 2.4.3 kernel with SMP turned on... and the nice option for 4Gigs of RAM... would the 64Gig option help me??? just wondering there...] Any pointer, advise, help, hint... laugh at the stupid thing I have forgotten is more than welcome.. tia Chris.