From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756051AbZLCNXQ (ORCPT ); Thu, 3 Dec 2009 08:23:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755774AbZLCNXP (ORCPT ); Thu, 3 Dec 2009 08:23:15 -0500 Received: from hera.kernel.org ([140.211.167.34]:32865 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755996AbZLCNXN (ORCPT ); Thu, 3 Dec 2009 08:23:13 -0500 Date: Thu, 3 Dec 2009 13:22:42 GMT From: "tip-bot for Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, laijs@cn.fujitsu.com, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, laijs@cn.fujitsu.com, mingo@elte.hu In-Reply-To: <12597846162906-git-send-email-> References: <12597846162906-git-send-email-> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/rcu] rcu: Make RCU's CPU-stall detector be default Message-ID: Git-Commit-ID: 8bfb2f8e655b9d0c45fde679fcd5fd97e34513db X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 8bfb2f8e655b9d0c45fde679fcd5fd97e34513db Gitweb: http://git.kernel.org/tip/8bfb2f8e655b9d0c45fde679fcd5fd97e34513db Author: Paul E. McKenney AuthorDate: Wed, 2 Dec 2009 12:10:16 -0800 Committer: Ingo Molnar CommitDate: Thu, 3 Dec 2009 11:35:27 +0100 rcu: Make RCU's CPU-stall detector be default The RCU_CPU_STALL_DETECTOR costs almost nothing and has located some bugs that might otherwise have been difficult to track down. Make it be default for the TREE RCU implementations. The vmlinux size impact is limited (on 64-bit x86 defconfig): text data bss dec hex filename 8440248 1260076 995588 10695912 a334e8 vmlinux.before 8440774 1260060 995588 10696422 a336e6 vmlinux.after +526 bytes - acceptable default cost. For RAM starved systems, TINY_RCU does not support CPU-stall detection and is much smaller, but then again it is a uniprocessor... Signed-off-by: Paul E. McKenney Acked-by: Lai Jiangshan Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12597846162906-git-send-email-> [ v2: added image size calculations to the changelog ] Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8911558..50e0e78 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -749,7 +749,7 @@ config RCU_TORTURE_TEST_RUNNABLE config RCU_CPU_STALL_DETECTOR bool "Check for stalled CPUs delaying RCU grace periods" depends on TREE_RCU || TREE_PREEMPT_RCU - default n + default y help This option causes RCU to printk information on which CPUs are delaying the current grace period, but only when