From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935032Ab3DOVKd (ORCPT ); Mon, 15 Apr 2013 17:10:33 -0400 Received: from mail-wg0-f44.google.com ([74.125.82.44]:50579 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933505Ab3DOVK3 (ORCPT ); Mon, 15 Apr 2013 17:10:29 -0400 From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Chris Metcalf , Christoph Lameter , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Kevin Hilman , Li Zhong , "Paul E. McKenney" , Paul Gortmaker , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Subject: [PATCH 1/5] nohz: Fix old dynticks idle Kconfig backward compatibility Date: Mon, 15 Apr 2013 23:10:16 +0200 Message-Id: <1366060220-20271-2-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1366060220-20271-1-git-send-email-fweisbec@gmail.com> References: <1366060220-20271-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to enforce backward compatibility with older config files, we want the new dynticks-idle Kconfig entry to default its value to the one of the old CONFIG_NO_HZ symbol if present. Namely we want: config NO_HZ # old obsolete dynticks idle symbol bool config NO_HZ_IDLE # new dynticks idle symbol default NO_HZ However Kconfig prevents this to work if the old symbol is not visible. And this is currently the case because NO_HZ lacks a title in order to show it in make oldconfig and alike. To fix this, bring a minimal title and help text to the obsolete Kconfig entry that explains its purpose. This makes the "defaulting" to work. Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: Chris Metcalf Cc: Christoph Lameter Cc: Geoff Levand Cc: Gilad Ben Yossef Cc: Hakan Akkan Cc: Ingo Molnar Cc: Kevin Hilman Cc: Li Zhong Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- kernel/time/Kconfig | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 27cc404..cbe64be 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -75,10 +75,6 @@ config NO_HZ_COMMON depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS select TICK_ONESHOT -# Kept around for compatibility, maps to NO_HZ_IDLE -config NO_HZ - bool - choice prompt "Timer tick handling" default NO_HZ_IDLE if NO_HZ @@ -130,6 +126,14 @@ config NO_HZ_EXTENDED endchoice +config NO_HZ + bool "Old Idle dynticks config" + depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS + help + This is the old config entry that enables dynticks idle. + We keep it around for a little while to enforce backward + compatibility with older config files. + config HIGH_RES_TIMERS bool "High Resolution Timer Support" depends on !ARCH_USES_GETTIMEOFFSET && GENERIC_CLOCKEVENTS -- 1.7.5.4