Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764078AbXETH0a (ORCPT ); Sun, 20 May 2007 03:26:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759564AbXETH0W (ORCPT ); Sun, 20 May 2007 03:26:22 -0400 Received: from holomorphy.com ([66.93.40.71]:59638 "EHLO holomorphy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759441AbXETH0V (ORCPT ); Sun, 20 May 2007 03:26:21 -0400 Date: Sun, 20 May 2007 00:26:05 -0700 From: William Lee Irwin III To: Andrew Morton Cc: Nick Piggin , Christoph Lameter , Linux Kernel Mailing List , Linux Memory Management List , linux-arch@vger.kernel.org Subject: Re: [rfc] increase struct page size?! Message-ID: <20070520072605.GE19966@holomorphy.com> References: <20070518040854.GA15654@wotan.suse.de> <20070519012530.GB15569@wotan.suse.de> <20070519181501.GC19966@holomorphy.com> <20070519150934.bdabc9b5.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070519150934.bdabc9b5.akpm@linux-foundation.org> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 826 Lines: 19 On Sat, 19 May 2007 11:15:01 -0700 William Lee Irwin III wrote: >> Much the same holds for the atomic_t's; 32 + PAGE_SHIFT is >> 44 bits or more, about as much as is possible, and one reference per >> page per page is not even feasible. Full-length atomic_t's are just >> not necessary. On Sat, May 19, 2007 at 03:09:34PM -0700, Andrew Morton wrote: > You can overflow a page's refcount by mapping it 4G times. That requires > 32GB of pagetable memory. It's quite feasible with remap_file_pages(). Oh dear, worst-case app behavior. I'm just wrong. -- wli - 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/