Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754415AbZJPSn1 (ORCPT ); Fri, 16 Oct 2009 14:43:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753754AbZJPSn0 (ORCPT ); Fri, 16 Oct 2009 14:43:26 -0400 Received: from smtp-out.google.com ([216.239.45.13]:22522 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751556AbZJPSn0 (ORCPT ); Fri, 16 Oct 2009 14:43:26 -0400 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=QyUMPu3nZTbMB1Qj7Qx2J9ekKscsXyHko3GbENL5mfuFcU93g3WRUi9dN3e0SR66z 3SX+lM9SC3gVGviECqcgQ== Date: Fri, 16 Oct 2009 11:43:23 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Christoph Lameter cc: Mel Gorman , Pekka Enberg , Tejun Heo , linux-kernel@vger.kernel.org, Mathieu Desnoyers , Zhang Yanmin Subject: Re: [this_cpu_xx V6 7/7] this_cpu: slub aggressive use of this_cpu operations in the hotpaths In-Reply-To: Message-ID: References: <4AD307A5.105@kernel.org> <84144f020910120614r529d8e4em9babe83a90e9371f@mail.gmail.com> <4AD4D8B6.6010700@cs.helsinki.fi> <20091014133457.GB5027@csn.ul.ie> User-Agent: Alpine 1.00 (DEB 882 2007-12-20) 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: 1320 Lines: 30 On Fri, 16 Oct 2009, Christoph Lameter wrote: > > TCP_STREAM stresses a few specific caches: > > > > ALLOC_FASTPATH ALLOC_SLOWPATH FREE_FASTPATH FREE_SLOWPATH > > kmalloc-256 3868530 3450592 95628 7223491 > > kmalloc-1024 2440434 429 2430825 10034 > > kmalloc-4096 3860625 1036723 85571 4811779 > > > > This demonstrates that freeing to full (or partial) slabs causes a lot of > > pain since the fastpath normally can't be utilized and that's probably > > beyond the scope of this patchset. > > > > It's also different from the cpu slab thrashing issue I identified with > > the TCP_RR benchmark and had a patchset to somewhat improve. The > > criticism was the addition of an increment to a fastpath counter in struct > > kmem_cache_cpu which could probably now be much cheaper with these > > optimizations. > > Can you redo the patch? > Sure, but it would be even more inexpensive if we can figure out why the irqless patch is hanging my netserver machine within the first 60 seconds on the TCP_RR benchmark. I guess nobody else has reproduced that yet. -- 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/