Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756796AbYHDOso (ORCPT ); Mon, 4 Aug 2008 10:48:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753519AbYHDOse (ORCPT ); Mon, 4 Aug 2008 10:48:34 -0400 Received: from mail2.shareable.org ([80.68.89.115]:45889 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753075AbYHDOse (ORCPT ); Mon, 4 Aug 2008 10:48:34 -0400 Date: Mon, 4 Aug 2008 15:48:23 +0100 From: Jamie Lokier To: Christoph Lameter Cc: Matthew Wilcox , Pekka Enberg , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mel Gorman , andi@firstfloor.org, Rik van Riel Subject: Re: No, really, stop trying to delete slab until you've finished making slub perform as well Message-ID: <20080804144823.GE18868@shareable.org> References: <20080801182324.572058187@lameter.com> <20080803015847.GD26461@parisc-linux.org> <48970779.80902@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48970779.80902@linux-foundation.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1330 Lines: 30 Christoph Lameter wrote: > Matthew Wilcox wrote: > > On Fri, May 09, 2008 at 07:21:01PM -0700, Christoph Lameter wrote: > >> - Add a patch that obsoletes SLAB and explains why SLOB does not support > >> defrag (Either of those could be theoretically equipped to support > >> slab defrag in some way but it seems that Andrew/Linus want to reduce > >> the number of slab allocators). > > > > Do we have to once again explain that slab still outperforms slub on at > > least one important benchmark? I hope Nick Piggin finds time to finish > > tuning slqb; it already outperforms slub. > > > > Uhh. I forgot to delete that statement. I did not include the patch > in the series. > > We have a fundamental issue design issue there. Queuing on free can result in > better performance as in SLAB. However, it limits concurrency (per node lock > taking) and causes latency spikes due to queue processing (f.e. one test load > had 118.65 vs. 34 usecs just by switching to SLUB). Vaguely on this topic, has anyone studied the effects of SLAB/SLUB etc. on MMUless systems? -- Jamie -- 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/