lkml.org 
[lkml]   [2010]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:core/rcu] rcu: Give different levels of the rcu_node hierarchy distinct lockdep names
Commit-ID:  b6407e863934965cdc66cbc244d811ceeb6f4d77
Gitweb: http://git.kernel.org/tip/b6407e863934965cdc66cbc244d811ceeb6f4d77
Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
AuthorDate: Mon, 4 Jan 2010 16:04:02 -0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 13 Jan 2010 09:06:07 +0100

rcu: Give different levels of the rcu_node hierarchy distinct lockdep names

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 <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
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: <12626498421830-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
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;

\
 
 \ /
  Last update: 2010-01-13 11:31    [from the cache]
©2003-2011 Jasper Spaans