From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267193AbUHRPaf (ORCPT ); Wed, 18 Aug 2004 11:30:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267194AbUHRPae (ORCPT ); Wed, 18 Aug 2004 11:30:34 -0400 Received: from relay.pair.com ([209.68.1.20]:64782 "HELO relay.pair.com") by vger.kernel.org with SMTP id S267193AbUHRPaR (ORCPT ); Wed, 18 Aug 2004 11:30:17 -0400 X-pair-Authenticated: 68.42.66.6 Subject: Re: Help with mapping memory into kernel space? From: Daniel Gryniewicz To: Brian McGrew Cc: linux-kernel@vger.kernel.org In-Reply-To: References: Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 18 Aug 2004 11:30:15 -0400 Message-Id: <1092843015.14961.2.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 1.5.92 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2004-08-17 at 22:39 -0700, Brian McGrew wrote: > Good day All: > > The overall problem is that the more system memory we install, > the fewer IBB's we can use. For instance, 256MB lets us use > four IBB's; 512MB lets us use three IBB's and so on. Basicly, > the kernel blows up trying to map memory. Each IBB has two > banks of 64MB of RAM on them which we try and memmap to system > memory for speed of addressing. So essentaily, we're sending > out four camera systems with only 256MB of memory which is only > about one quarter of what we need. On x86, the kernel has 1 GiB of address space. Try the 2G/2G split patches, or the 4G/4G patches, either one of which should increase your kernel address space enough to map both memory and your buffers. Daniel