From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764924AbXKOBEB (ORCPT ); Wed, 14 Nov 2007 20:04:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755481AbXKOBDu (ORCPT ); Wed, 14 Nov 2007 20:03:50 -0500 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:34833 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753861AbXKOBDt (ORCPT ); Wed, 14 Nov 2007 20:03:49 -0500 Date: Wed, 14 Nov 2007 17:03:25 -0800 (PST) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: David Miller cc: herbert@gondor.apana.org.au, nickpiggin@yahoo.com.au, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: 2.6.24-rc2: Network commit causes SLUB performance regression with tbench In-Reply-To: <20071114.154616.46285694.davem@davemloft.net> Message-ID: References: <200711140927.39796.nickpiggin@yahoo.com.au> <20071114.031022.183117678.davem@davemloft.net> <20071114114844.GA13927@gondor.apana.org.au> <20071114.154616.46285694.davem@davemloft.net> 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 On Wed, 14 Nov 2007, David Miller wrote: > > As a result, we may allocate more than a page of data in the > > non-TSO case when exactly one page is desired. Well this is likely the result of the SLUB regression. If you allocate an order 1 page then the zone locks need to be taken. SLAB queues the a couple of higher order pages and can so serve a couple of requests without going into the page allocator whereas SLUB has to go directly to the page allocator for allocate and free. I guess that needs fixing in the page allocator. Or do I need to add a mechanism to buffer higher order page allcoations to SLUB?