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 14:09:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 3 May 2002 14:09:27 -0400 Received: from dsl-213-023-039-070.arcor-ip.net ([213.23.39.70]:52648 "EHLO starship") by vger.kernel.org with ESMTP id ; Fri, 3 May 2002 14:09:26 -0400 Content-Type: text/plain; charset=US-ASCII From: Daniel Phillips To: Andrea Arcangeli Subject: Re: Virtual address space exhaustion (was Discontigmem virt_to_page() ) Date: Fri, 3 May 2002 20:08:33 +0200 X-Mailer: KMail [version 1.3.2] Cc: "Martin J. Bligh" , William Lee Irwin III , linux-kernel@vger.kernel.org In-Reply-To: <20020503103813.K11414@dualathlon.random> <20020503185806.A1396@dualathlon.random> 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 Friday 03 May 2002 18:58, Andrea Arcangeli wrote: > On Fri, May 03, 2002 at 06:41:15PM +0200, Daniel Phillips wrote: > > On Friday 03 May 2002 18:20, Andrea Arcangeli wrote: > > > 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. > > > > The topic here is 'page clustering'. The idea is to use one struct page for > > every four 4K page frames on ia32. > > ah ok, I meant physical hardware pages. physical hardware pages should > be doable without common code changes, a software PAGE_SIZE or the > PAGE_CACHE_SIZE raises non trivial problems instead. Yes, it's not too bad though. In the swap-in path, the locking would be against mem_map + (pfn >> 2). The four pages don't have to be read in and valid all at the same time - it's ok to take multiple faults on the cluster, not recommended, but ok. In the swap-out path, all four page frames have to be swapped out and invalidated at the same time. -- Daniel