From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1757886AbYHVUEt@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757886AbYHVUEt (ORCPT <rfc822;w@1wt.eu>);
	Fri, 22 Aug 2008 16:04:49 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754427AbYHVUEl
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Fri, 22 Aug 2008 16:04:41 -0400
Received: from smtp1.linux-foundation.org ([140.211.169.13]:53221 "EHLO
	smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1754319AbYHVUEk (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 22 Aug 2008 16:04:40 -0400
Message-ID: <48AF1B81.3050806@linux-foundation.org>
Date: Fri, 22 Aug 2008 15:03:13 -0500
From: Christoph Lameter <cl@linux-foundation.org>
User-Agent: Thunderbird 2.0.0.16 (Windows/20080708)
MIME-Version: 1.0
To: paulmck@linux.vnet.ibm.com
CC: Pekka Enberg <penberg@cs.helsinki.fi>, Ingo Molnar <mingo@elte.hu>,
       Jeremy Fitzhardinge <jeremy@goop.org>,
       Nick Piggin <nickpiggin@yahoo.com.au>, Andi Kleen <andi@firstfloor.org>,
       "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com>,
       Suresh Siddha <suresh.b.siddha@intel.com>,
       Jens Axboe <jens.axboe@oracle.com>,
       Rusty Russell <rusty@rustcorp.com.au>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] smp_call_function: use rwlocks on queues rather	than
 rcu
References: <48AE0883.6050701@goop.org> <20080822062800.GQ14110@elte.hu> <84144f020808220006n25d684b1n9db306ddc4f58c4c@mail.gmail.com> <48AEC6B2.1080701@linux-foundation.org> <20080822151156.GA6744@linux.vnet.ibm.com> <48AEF3FD.70906@linux-foundation.org> <20080822182915.GG6744@linux.vnet.ibm.com> <48AF0735.60402@linux-foundation.org> <20080822195226.GJ6744@linux.vnet.ibm.com>
In-Reply-To: <20080822195226.GJ6744@linux.vnet.ibm.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Paul E. McKenney wrote:

> I was indeed thinking in terms of the free from RCU being specially marked.

Isnt there some way to shorten the rcu periods significantly? Critical
sections do not take that long after all.

If the RCU periods are much shorter then the chance of cache hotness of the
objects is increased.