From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751314Ab0CCPr6 (ORCPT ); Wed, 3 Mar 2010 10:47:58 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:48873 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753023Ab0CCPrJ (ORCPT ); Wed, 3 Mar 2010 10:47:09 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 4/4] rcu: add control variables to lockdep_rcu_dereference() diagnostics Date: Wed, 3 Mar 2010 07:46:59 -0800 Message-Id: <1267631219-8713-4-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.6.6 In-Reply-To: <20100303154638.GA8576@linux.vnet.ibm.com> References: <20100303154638.GA8576@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add the values of rcu_scheduler_active() and debug_locks() to the lockdep_rcu_dereference() output to help diagnose RCU lockdep splats that occur shortly after the scheduler starts. Signed-off-by: Paul E. McKenney --- kernel/lockdep.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/kernel/lockdep.c b/kernel/lockdep.c index 0c30d04..681bc2e 100644 --- a/kernel/lockdep.c +++ b/kernel/lockdep.c @@ -3822,6 +3822,7 @@ void lockdep_rcu_dereference(const char *file, const int line) printk("%s:%d invoked rcu_dereference_check() without protection!\n", file, line); printk("\nother info that might help us debug this:\n\n"); + printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks); lockdep_print_held_locks(curr); printk("\nstack backtrace:\n"); dump_stack(); -- 1.6.6