Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753880AbYGROTU (ORCPT ); Fri, 18 Jul 2008 10:19:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751001AbYGROTN (ORCPT ); Fri, 18 Jul 2008 10:19:13 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:60132 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbYGROTM (ORCPT ); Fri, 18 Jul 2008 10:19:12 -0400 Message-ID: <4880A613.1060002@linux-foundation.org> Date: Fri, 18 Jul 2008 09:17:55 -0500 From: Christoph Lameter User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: Richard Kennedy CC: penberg@cs.helsinki.fi, mpm@selenic.com, linux-mm , lkml , Mel Gorman Subject: Re: [PATCH][RFC] slub: increasing order reduces memory usage of some key caches References: <1216211371.3122.46.camel@castor.localdomain> <487DF5D4.9070101@linux-foundation.org> <1216216730.3122.60.camel@castor.localdomain> <487DFFBE.5050407@linux-foundation.org> <1216375025.3082.7.camel@castor.localdomain> In-Reply-To: <1216375025.3082.7.camel@castor.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1285 Lines: 34 Richard Kennedy wrote: > Slabcache: dentry Aliases: 0 Order : 0 Objects: 22553 > ** Reclaim accounting active > > Sizes (bytes) Slabs Debug Memory > ------------------------------------------------------------------------ > Object : 208 Total : 1188 Sanity Checks : Off Total: 4866048 > SlabObj: 208 Full : 1186 Redzoning : Off Used : 4691024 > SlabSiz: 4096 Partial: 0 Poisoning : Off Loss : 175024 > Loss : 0 CpuSlab: 2 Tracking : Off Lalig: 0 > Align : 8 Objects: 19 Tracing : Off Lpadd: 171072 So we are using 1188 pages before make > and after a make kernel & a small delay 2399 pages after make > on 2.6.26 + my patch 579 * 2 = 1158 (saved 30 pages even before doing anything) before make > after the make 2025 *2 = 4050 pages which are much more than the 2399 with order 0. So we are wasting a lot more space. You'd probably need to run slab defrag to get that memory back. -- 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/