From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756364Ab0DITtw (ORCPT ); Fri, 9 Apr 2010 15:49:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35269 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756339Ab0DITtu (ORCPT ); Fri, 9 Apr 2010 15:49:50 -0400 Date: Fri, 9 Apr 2010 15:49:20 -0400 From: Jason Baron To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, mathieu.desnoyers@polymtl.ca, hpa@zytor.com, tglx@linutronix.de, rostedt@goodmis.org, andi@firstfloor.org, roland@redhat.com, rth@redhat.com, mhiramat@redhat.com, fweisbec@gmail.com, avi@redhat.com Message-Id: In-Reply-To: References: Subject: [PATCH 1/9] jump label: notifier atomic call chain notrace Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In LTTng, being able to use the atomic notifier from cpu idle entry to ensure the tracer flush the last events in the current subbuffer requires the rcu read-side to be marked "notrace", otherwise it can end up calling back into lockdep and the tracer. Also apply to the the die notifier. Signed-off-by: Mathieu Desnoyers Signed-off-by: Jason Baron Reviewed-by: Masami Hiramatsu --- kernel/notifier.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/notifier.c b/kernel/notifier.c index 2488ba7..88453a7 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -148,7 +148,7 @@ int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, spin_lock_irqsave(&nh->lock, flags); ret = notifier_chain_unregister(&nh->head, n); spin_unlock_irqrestore(&nh->lock, flags); - synchronize_rcu(); + synchronize_sched(); return ret; } EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); @@ -178,9 +178,9 @@ int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, { int ret; - rcu_read_lock(); + rcu_read_lock_sched_notrace(); ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); - rcu_read_unlock(); + rcu_read_unlock_sched_notrace(); return ret; } EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); -- 1.7.0.1