Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755227AbYJGOpn (ORCPT ); Tue, 7 Oct 2008 10:45:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754198AbYJGOp1 (ORCPT ); Tue, 7 Oct 2008 10:45:27 -0400 Received: from relay.2ka.mipt.ru ([194.85.80.65]:57631 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961AbYJGOpW (ORCPT ); Tue, 7 Oct 2008 10:45:22 -0400 Date: Tue, 7 Oct 2008 18:29:02 +0400 From: Evgeniy Polyakov To: Christoph Lameter Cc: Corey Minyard , David Miller , dada1@cosmosbay.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, shemminger@vyatta.com, paulmck@linux.vnet.ibm.com Subject: Re: [PATCH 3/3] Convert the UDP hash lock to RCU Message-ID: <20081007142902.GA26302@2ka.mipt.ru> References: <20081006185026.GA10383@minyard.local> <48EA8197.6080502@cosmosbay.com> <20081006.144002.56418911.davem@davemloft.net> <48EA9A59.1090306@acm.org> <20081007083750.GB17079@2ka.mipt.ru> <48EB6F2D.100@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48EB6F2D.100@linux-foundation.org> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 793 Lines: 19 On Tue, Oct 07, 2008 at 09:16:13AM -0500, Christoph Lameter (cl@linux-foundation.org) wrote: > > I tested skb destruction via RCU path, and got 2.5 times worse numbers > > with small-packets-bulk-transfer workload. > > Was this with regular RCU freeing? This will cool down the cacheline before > frees. You need SLAB_DESTROY_BY_RCU to keep the objects cache hot. I believe there were no SLAB_DESTROY_BY_RCU 2 yars ago :) It was pure call_rcu(&skb->rcu, real_skb_freeing), where real_skb_freeing() just did usual kfree(). -- Evgeniy Polyakov -- 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/