From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752652AbZIERGa (ORCPT ); Sat, 5 Sep 2009 13:06:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752536AbZIERG3 (ORCPT ); Sat, 5 Sep 2009 13:06:29 -0400 Received: from turing-police.cc.vt.edu ([128.173.14.107]:47943 "EHLO turing-police.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751423AbZIERG3 (ORCPT ); Sat, 5 Sep 2009 13:06:29 -0400 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: "Paul E. McKenney" , Andrew Morton Cc: linux-kernel@vger.kernel.org Subject: RCU Kconfig help text From: Valdis.Kletnieks@vt.edu Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1252157230_2420P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Sat, 05 Sep 2009 09:27:10 -0400 Message-ID: <12924.1252157230@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1252157230_2420P Content-Type: text/plain; charset=us-ascii init/Kconfig says: "choice prompt "RCU Implementation" default TREE_RCU config TREE_RCU bool "Tree-based hierarchical RCU" help This option selects the RCU implementation that is designed for very large SMP system with hundreds or thousands of CPUs. It also scales down nicely to smaller systems. config TREE_PREEMPT_RCU bool "Preemptable tree-based hierarchical RCU" depends on PREEMPT help This option selects the RCU implementation that is designed for very large SMP systems with hundreds or thousands of CPUs, but for which real-time response is also required. endchoice" This leaves somebody who has a laptop wondering which choice is best for a system with only one or two cores that has CONFIG_PREEMPT defined. One choice says it scales down nicely, the other explicitly has a 'depends on PREEMPT' attached to it... (Yes, I realize in practice, the RCU sections on a laptop are probably usually so short they don't matter in practice. I finally concluded TREE_PREEMPT was apparently a rename of CONFIG_PREEMPT_RCU and went with that since that was working for me before...) --==_Exmh_1252157230_2420P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFKomcucC3lWbTT17ARAsNHAKDsJbCbSXHwXFTyjtae5RN81B9s2ACg2MSB YjUnqcllZFVODsaSo7h+NFY= =WpR2 -----END PGP SIGNATURE----- --==_Exmh_1252157230_2420P--