Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755699AbXJAVKW (ORCPT ); Mon, 1 Oct 2007 17:10:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752657AbXJAVKJ (ORCPT ); Mon, 1 Oct 2007 17:10:09 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:43581 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752700AbXJAVKH (ORCPT ); Mon, 1 Oct 2007 17:10:07 -0400 Date: Mon, 1 Oct 2007 14:10:06 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Mel Gorman cc: Nick Piggin , Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Chinner , Jens Axboe , akpm@linux-foundation.org Subject: Re: [15/17] SLUB: Support virtual fallback via SLAB_VFALLBACK In-Reply-To: <20070928210527.GB30404@skynet.ie> Message-ID: References: <20070919033605.785839297@sgi.com> <20070919033643.763818012@sgi.com> <200709280742.38262.nickpiggin@yahoo.com.au> <20070928210527.GB30404@skynet.ie> 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: 1236 Lines: 32 On Fri, 28 Sep 2007, Mel Gorman wrote: > Minimally, SLUB by default should continue to use order-0 pages. Peter has > managed to bust order-1 pages with mem=128MB. Admittedly, it was a really > hostile workload but the point remains. It was artifically worked around > with min_free_kbytes (value set based on pageblock_order, could also have > been artifically worked around by dropping pageblock_order) and he eventually > caused order-0 failures so the workload is pretty damn hostile to everything. SLAB default is order 1 so is SLUB default upstream. SLAB does runtime detection of the amount of memory and configures the max order correspondingly: from mm/slab.c: /* * Fragmentation resistance on low memory - only use bigger * page orders on machines with more than 32MB of memory. */ if (num_physpages > (32 << 20) >> PAGE_SHIFT) slab_break_gfp_order = BREAK_GFP_ORDER_HI; We could duplicate something like that for SLUB. - 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/