Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934050AbZKXVWL (ORCPT ); Tue, 24 Nov 2009 16:22:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933487AbZKXVWK (ORCPT ); Tue, 24 Nov 2009 16:22:10 -0500 Received: from smtp-out.google.com ([216.239.45.13]:29240 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933406AbZKXVWJ (ORCPT ); Tue, 24 Nov 2009 16:22:09 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=dHUr6xYlJEWNdP8YlzQ3dNOlbp7bit9iElX5K5B4VNVUxhRA9MvZvBBd0x+T/vBKX 5c0kDPGjB6JEVDtAgJfLg== Date: Tue, 24 Nov 2009 13:22:08 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Peter Zijlstra cc: Matt Mackall , paulmck@linux.vnet.ibm.com, Pekka Enberg , linux-mm@kvack.org, Christoph Lameter , LKML , Nick Piggin Subject: Re: lockdep complaints in slab allocator In-Reply-To: <1259097150.4531.1822.camel@laptop> Message-ID: References: <84144f020911192249l6c7fa495t1a05294c8f5b6ac8@mail.gmail.com> <1258709153.11284.429.camel@laptop> <84144f020911200238w3d3ecb38k92ca595beee31de5@mail.gmail.com> <1258714328.11284.522.camel@laptop> <4B067816.6070304@cs.helsinki.fi> <1258729748.4104.223.camel@laptop> <1259002800.5630.1.camel@penberg-laptop> <1259003425.17871.328.camel@calx> <4B0ADEF5.9040001@cs.helsinki.fi> <1259080406.4531.1645.camel@laptop> <20091124170032.GC6831@linux.vnet.ibm.com> <1259082756.17871.607.camel@calx> <1259086459.4531.1752.camel@laptop> <1259090615.17871.696.camel@calx> <1259095580.4531.1788.camel@laptop> <1259096004.17871.716.camel@calx> <1259096519.4531.1809.camel@laptop> <1259097150.4531.1822.camel@laptop> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1302 Lines: 28 On Tue, 24 Nov 2009, Peter Zijlstra wrote: > > slqb still has a 5-10% performance regression compared to slab for > > benchmarks such as netperf TCP_RR on machines with high cpu counts, > > forcing that type of regression isn't acceptable. > > Having _4_ slab allocators is equally unacceptable. > So you just advocated to merging slqb so that it gets more testing and development, and then use its inclusion in a statistic to say we should remove others solely because the space is too cluttered? We use slab partially because the regression in slub was too severe for some of our benchmarks, and while CONFIG_SLUB may be the kernel default there are still distros that use slab as the default as well. We cannot simply remove an allocator that is superior to others because it is old or has increased complexity. I'd suggest looking at how widely used slob is and whether it has a significant advantage over slub. We'd then have two allocators for specialized workloads (and slub is much better for diagnostics) and one in development. -- 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/