From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 14E636B004A for ; Sat, 18 Jun 2011 17:55:39 -0400 (EDT) Date: Sat, 18 Jun 2011 14:55:46 -0700 From: Andrew Morton Subject: Re: [PATCH 2/12] mm: let swap use exceptional entries Message-Id: <20110618145546.12e175bf.akpm@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org On Tue, 14 Jun 2011 03:43:47 -0700 (PDT) Hugh Dickins wrote: > In an i386 kernel this limits its information (type and page offset) > to 30 bits: given 32 "types" of swapfile and 4kB pagesize, that's > a maximum swapfile size of 128GB. Which is less than the 512GB we > previously allowed with X86_PAE (where the swap entry can occupy the > entire upper 32 bits of a pte_t), but not a new limitation on 32-bit > without PAE; and there's not a new limitation on 64-bit (where swap > filesize is already limited to 16TB by a 32-bit page offset). hm. > Thirty > areas of 128GB is probably still enough swap for a 64GB 32-bit machine. What if it was only one area? 128GB is close enough to 64GB (or, more realistically, 32GB) to be significant. For the people out there who are using a single 200GB swap partition and actually needed that much, what happens? swapon fails? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org