Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753000AbZJPQxN (ORCPT ); Fri, 16 Oct 2009 12:53:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751157AbZJPQxN (ORCPT ); Fri, 16 Oct 2009 12:53:13 -0400 Received: from smtp2.ultrahosting.com ([74.213.174.253]:47086 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750722AbZJPQxM (ORCPT ); Fri, 16 Oct 2009 12:53:12 -0400 Date: Fri, 16 Oct 2009 12:45:26 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: David Rientjes 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 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 26 On Thu, 15 Oct 2009, David Rientjes 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? -- 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/