From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 19 May 2007 15:09:34 -0700 From: Andrew Morton Subject: Re: [rfc] increase struct page size?! Message-Id: <20070519150934.bdabc9b5.akpm@linux-foundation.org> In-Reply-To: <20070519181501.GC19966@holomorphy.com> References: <20070518040854.GA15654@wotan.suse.de> <20070519012530.GB15569@wotan.suse.de> <20070519181501.GC19966@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: William Lee Irwin III Cc: Nick Piggin , Christoph Lameter , Linux Kernel Mailing List , Linux Memory Management List , linux-arch@vger.kernel.org List-ID: 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. 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(). -- 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/ . Don't email: email@kvack.org