From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 3 May 2002 12:19:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 3 May 2002 12:19:46 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:60181 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Fri, 3 May 2002 12:19:46 -0400 Date: Fri, 3 May 2002 18:20:28 +0200 From: Andrea Arcangeli To: Daniel Phillips Cc: "Martin J. Bligh" , William Lee Irwin III , linux-kernel@vger.kernel.org Subject: Re: Virtual address space exhaustion (was Discontigmem virt_to_page() ) Message-ID: <20020503182028.C14505@dualathlon.random> In-Reply-To: <20020503103813.K11414@dualathlon.random> <4055279713.1020413842@[10.10.2.3]> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.22.1i X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 03, 2002 at 06:02:18PM +0200, Daniel Phillips wrote: > and solves 75% of the problem. It's not just ia32 numa that will benefit > from it. For example, MIPS supports 16K pages in software, which will the whole change would be specific to ia32, I don't see the connection with mips. There would be nothing to share between ia32 2M pages and mips 16K pages. You can do mips 16K just now indipendently from the page_size of ia32. 16K should work without surprises because other archs have pages of this size and even bigger. Nobody has pages large as much as 2M yet, that's an order of magnitude bigger. 16K for example is just fine for the read()/pagein/pageout I/O, DMA is usually done in larger chunks anyways with readahead and async-flushing to be faster (but never as big as 2M, the highest limit is 512k per scsi command). Andrea