From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 1 May 2002 21:35:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 1 May 2002 21:35:01 -0400 Received: from dsl-213-023-038-139.arcor-ip.net ([213.23.38.139]:6298 "EHLO starship") by vger.kernel.org with ESMTP id ; Wed, 1 May 2002 21:35:00 -0400 Content-Type: text/plain; charset=US-ASCII From: Daniel Phillips To: Anton Blanchard , Andrea Arcangeli Subject: Re: Bug: Discontigmem virt_to_page() [Alpha,ARM,Mips64?] Date: Wed, 1 May 2002 03:35:20 +0200 X-Mailer: KMail [version 1.3.2] Cc: Russell King , linux-kernel@vger.kernel.org, Jesse Barnes In-Reply-To: <20020426192711.D18350@flint.arm.linux.org.uk> <20020502011750.M11414@dualathlon.random> <20020502002010.GA14243@krispykreme> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 02 May 2002 02:20, Anton Blanchard wrote: > > so ia64 is one of those archs with a ram layout with huge holes in the > > middle of the ram of the nodes? I'd be curious to know what's the > > hardware advantage of designing the ram layout in such a way, compared > > to all other numa archs that I deal with. Also if you know other archs > > with huge holes in the middle of the ram of the nodes I'd be curious to > > know about them too. thanks for the interesting info! > > From arch/ppc64/kernel/iSeries_setup.c: > > * The iSeries may have very large memories ( > 128 GB ) and a partition > * may get memory in "chunks" that may be anywhere in the 2**52 real > * address space. The chunks are 256K in size. > > Also check out CONFIG_MSCHUNKS code and see why I'd love to see a generic > solution to this problem. Using the config_nonlinear model, you'd change the four mapping functions: logical_to_phys phys_to_logical pagenum_to_phys phys_to_pagenum to use a hash table instead of a table lookup. Bill Irwin suggested a btree would work here as well. (Note I'm trying out the term 'pagenum' instead of 'ordinal' here, following comments on lse-tech.) -- Daniel