Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261269AbVABQTG (ORCPT ); Sun, 2 Jan 2005 11:19:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261272AbVABQTF (ORCPT ); Sun, 2 Jan 2005 11:19:05 -0500 Received: from mail-relay-2.tiscali.it ([213.205.33.42]:29136 "EHLO mail-relay-2.tiscali.it") by vger.kernel.org with ESMTP id S261269AbVABQTA (ORCPT ); Sun, 2 Jan 2005 11:19:00 -0500 Date: Sun, 2 Jan 2005 17:18:20 +0100 From: Andrea Arcangeli To: Jens Axboe Cc: William Lee Irwin III , Rik van Riel , Andrew Morton , linux-kernel@vger.kernel.org, Robert_Hentosh@Dell.com, Con Kolivas Subject: Re: [PATCH][1/2] adjust dirty threshold for lowmem-only mappings Message-ID: <20050102161820.GG5164@dualathlon.random> References: <20041220125443.091a911b.akpm@osdl.org> <20041224160136.GG4459@dualathlon.random> <20041224164024.GK4459@dualathlon.random> <20041225020707.GQ13747@dualathlon.random> <20041225190710.GZ771@holomorphy.com> <20050102151147.GA1930@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050102151147.GA1930@suse.de> X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 991 Lines: 23 On Sun, Jan 02, 2005 at 04:11:47PM +0100, Jens Axboe wrote: > It should be lifted for block devices, it doesn't make any sense. It cannot be lifted without: 1) creating aliasing between buffercache and blkdev pagecache 2) changing all fs to kmap around all buffercache accesses 2 would create an huge change (sure not a good idea during 2.6, 2.7 if something). 1 would break lilo and tunefs and other things writing to a superblock while the fs is mounted. I effectively wrote it like 2 but I had to learn the hard way it broke lilo in some weird configuration and IIRC Linus and Al fixed it very nicely with current design. There's no highmem and in turn no limit on 64bit in the first place, so both efforts are worthless in the long term. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/