Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754172AbXIPSPW (ORCPT ); Sun, 16 Sep 2007 14:15:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752284AbXIPSPJ (ORCPT ); Sun, 16 Sep 2007 14:15:09 -0400 Received: from gir.skynet.ie ([193.1.99.77]:43816 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750892AbXIPSPH (ORCPT ); Sun, 16 Sep 2007 14:15:07 -0400 Date: Sun, 16 Sep 2007 19:15:04 +0100 To: Andrea Arcangeli Cc: Goswin von Brederlow , Andrew Morton , Joern Engel , Nick Piggin , Christoph Lameter , torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , William Lee Irwin III , David Chinner , Jens Axboe , Badari Pulavarty , Maxim Levitsky , Fengguang Wu , swin wang , totty.lu@gmail.com, hugh@veritas.com Subject: Re: [00/41] Large Blocksize Support V7 (adds memmap support) Message-ID: <20070916181504.GB16406@skynet.ie> References: <20070911060349.993975297@sgi.com> <200709110452.20363.nickpiggin@yahoo.com.au> <20070911121225.GE13132@lazybastard.org> <20070915014449.4f9cdb51.akpm@linux-foundation.org> <87ir6c3z2l.fsf@informatik.uni-tuebingen.de> <20070915155100.GA21861@v2.random> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20070915155100.GA21861@v2.random> User-Agent: Mutt/1.5.13 (2006-08-11) From: mel@skynet.ie (Mel Gorman) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 32 On (15/09/07 17:51), Andrea Arcangeli didst pronounce: > On Sat, Sep 15, 2007 at 02:14:42PM +0200, Goswin von Brederlow wrote: > > I keep coming back to the fact that movable objects should be moved > > out of the way for unmovable ones. Anything else just allows > > That's incidentally exactly what the slab does, no need to reinvent > the wheel for that, it's an old problem and there's room for > optimization in the slab partial-reuse logic too. Except now as I've repeatadly pointed out, you have internal fragmentation problems. If we went with the SLAB, we would need 16MB slabs on PowerPC for example to get the same sort of results and a lot of copying and moving when a suitable slab page was not available. > Just boost the order > 0 page size and use the slab to get the 4k chunks. The sgi/defrag > design is backwards. > Nothing stops you altering the PAGE_SIZE so that large blocks work in the way you envision and keep grouping pages by mobility for huge page sizes. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - 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/