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 11:38:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 3 May 2002 11:38:30 -0400 Received: from mail3.aracnet.com ([216.99.193.38]:32705 "EHLO mail3.aracnet.com") by vger.kernel.org with ESMTP id ; Fri, 3 May 2002 11:38:30 -0400 Date: Fri, 03 May 2002 08:38:03 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: William Lee Irwin III , Andrea Arcangeli cc: Daniel Phillips , Russell King , linux-kernel@vger.kernel.org Subject: Re: Bug: Discontigmem virt_to_page() [Alpha,ARM,Mips64?] Message-ID: <4056520097.1020415082@[10.10.2.3]> In-Reply-To: <20020503092643.GR32767@holomorphy.com> X-Mailer: Mulberry/2.1.2 (Win32) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Have you done testing with 64GB? What sort of failure modes are you > seeing with it? I've been hearing about more severe failure modes in > practice on 32GB, Martin, could you comment on this? I've never gone above 32Gb (yet ;-)). We don't have an SMP platform that I know of that'll support 64Gb, only the NUMA platforms. 32Gb will boot and work with 1GB KVA, but if you actually want to use the memory for something, a 2GB KVA seems imperative. It depends on the workload you're using, but the things we tend to see are: 1. struct page. 2. buffer heads (will look at -aa tree) 3. user page tables (need highpte) 4. LDTs for threads filling the vmalloc space (seems to be fixed in 2.5) I think the whole struct page issue needs some (complex, hard) work, but in general, we're getting there. Fast ;-) M. PS. BTW, Andrea, your latest highpte looks like you obliterated the kmap problem I was complaing of, but I've been having massive problems with other things which are blocking much of the real testing ... sorry about the time lag ;-)