From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754051Ab0AEAEO (ORCPT ); Mon, 4 Jan 2010 19:04:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753481Ab0AEAEM (ORCPT ); Mon, 4 Jan 2010 19:04:12 -0500 Received: from e8.ny.us.ibm.com ([32.97.182.138]:38870 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753903Ab0AEAEK (ORCPT ); Mon, 4 Jan 2010 19:04:10 -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 3/3] rcu: give different levels of the rcu_node hierarchy distinct lockdep names Date: Mon, 4 Jan 2010 16:04:02 -0800 Message-Id: <12626498421830-git-send-email-> X-Mailer: git-send-email 1.5.2.5 In-Reply-To: <20100105000337.GA23307@linux.vnet.ibm.com> References: <20100105000337.GA23307@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney Previously, each level of the rcu_node hierarchy had the same rather unimaginative name: "&rcu_node_class[i]". This makes lockdep diagnostics involving these lockdep classes less helpful than would be nice. This patch fixes this by giving each level of the rcu_node hierarchy a distinct name: "rcu_node_level_0", "rcu_node_level_1", and so on. This version of the patch includes improved diagnostics suggested by Josh Triplett and Peter Zijlstra. Signed-off-by: Paul E. McKenney --- kernel/rcutree.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 0a4c328..3b13d64 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1811,11 +1811,17 @@ static void __init rcu_init_levelspread(struct rcu_state *rsp) */ static void __init rcu_init_one(struct rcu_state *rsp) { + static char *buf[] = { "rcu_node_level_0", + "rcu_node_level_1", + "rcu_node_level_2", + "rcu_node_level_3" }; /* Match MAX_RCU_LVLS */ int cpustride = 1; int i; int j; struct rcu_node *rnp; + BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */ + /* Initialize the level-tracking arrays. */ for (i = 1; i < NUM_RCU_LVLS; i++) @@ -1829,7 +1835,8 @@ static void __init rcu_init_one(struct rcu_state *rsp) rnp = rsp->level[i]; for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) { spin_lock_init(&rnp->lock); - lockdep_set_class(&rnp->lock, &rcu_node_class[i]); + lockdep_set_class_and_name(&rnp->lock, + &rcu_node_class[i], buf[i]); rnp->gpnum = 0; rnp->qsmask = 0; rnp->qsmaskinit = 0; -- 1.5.2.5