From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755095AbYA0M0i (ORCPT ); Sun, 27 Jan 2008 07:26:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752572AbYA0M02 (ORCPT ); Sun, 27 Jan 2008 07:26:28 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:36422 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266AbYA0M02 (ORCPT ); Sun, 27 Jan 2008 07:26:28 -0500 Date: Sun, 27 Jan 2008 13:26:02 +0100 From: Ingo Molnar To: "Paul E. McKenney" Cc: Stefan Richter , linux-kernel@vger.kernel.org Subject: Re: preemptible RCU bug (was Re: [git pull] scheduler changes for v2.6.25) Message-ID: <20080127122602.GA17293@elte.hu> References: <20080125203740.GA31784@elte.hu> <479B87B9.8080005@s5r6.in-berlin.de> <20080127110559.GB28315@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080127110559.GB28315@linux.vnet.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Paul E. McKenney wrote: > > Sorry, no help available for this option yet. > > Good catch!!! > > This patch supplies help text for the "RCU implementation type" kernel > configuration choice. thanks applied to sched.git. (see the patch below - the config option is in init/Kconfig in mainline, not in kernel/Kconfig.preempt) Ingo -------------> Subject: RCU: add help text for "RCU implementation type" From: "Paul E. McKenney" This patch supplies help text for the "RCU implementation type" kernel configuration choice. Reported-by: Stefan Richter Signed-off-by: Paul E. McKenney Signed-off-by: Ingo Molnar --- init/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) Index: linux/init/Kconfig =================================================================== --- linux.orig/init/Kconfig +++ linux/init/Kconfig @@ -779,6 +779,14 @@ config PREEMPT_NOTIFIERS choice prompt "RCU implementation type:" default CLASSIC_RCU + help + This allows you to choose either the classic RCU implementation + that is designed for best read-side performance on non-realtime + systems, or the preemptible RCU implementation for best latency + on realtime systems. Note that some kernel preemption modes + will restrict your choice. + + Select the default if you are unsure. config CLASSIC_RCU bool "Classic RCU"