Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 25 Jul 2002 07:41:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 25 Jul 2002 07:41:28 -0400 Received: from leibniz.math.psu.edu ([146.186.130.2]:47022 "EHLO math.psu.edu") by vger.kernel.org with ESMTP id ; Thu, 25 Jul 2002 07:41:27 -0400 Date: Thu, 25 Jul 2002 07:44:40 -0400 (EDT) From: Alexander Viro To: Linus Torvalds cc: Matt_Domsch@Dell.com, Andries.Brouwer@cwi.nl, linux-kernel@vger.kernel.org Subject: RE: 2.5.28 and partitions In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1027 Lines: 24 On Wed, 24 Jul 2002, Linus Torvalds wrote: > Note that there is one place where 64 bits is simply _too_ expensive, and > that's the page cache. In particular, the "index" in "struct page". We > want to make "struct page" _smaller_, not larger. > > Right now that means that 16TB really is a hard limit for at least some > device access on a 32-bit machine with a 4kB page-size (yes, you could > make a filesystem that is bigger, but you very fundamentally cannot make > individual files larger than 16TB). ITYM "8Tb" - indices are signed, IIRC. OTOH, it's not 2^31 * PAGE_SIZE - it's 2^31 * PAGE_CACHE_SIZE, which can be bigger. Al, still thinking that anybody who does mkfs. on a multi-Tb device should seek professional help of the kind they don't give on l-k... - 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/