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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-08-09 14:23:03 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-08-20 09:00:11 -0700
commit8cdd32a918350430483751feaae1c19cef816f69 (patch)
treeb219bf5daf42a5fa0b48caf8b94174be2aa9a63f /kernel/rcutree.c
parent9079fd7c2e06a92cf27d05224a1f478581916c5b (diff)
rcu: refer RCU CPU stall-warning victims to stallwarn.txt
There is some documentation on RCU CPU stall warnings contained in Documentation/RCU/stallwarn.txt, but it will not be apparent to someone who runs into such a warning while under time pressure. This commit therefore adds comments preceding the printk()s pointing out the location of this documentation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree.c')
-rw-r--r--kernel/rcutree.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 5aab7dabd0d..ff214118e4b 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -487,8 +487,11 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
rcu_print_task_stall(rnp);
raw_spin_unlock_irqrestore(&rnp->lock, flags);
- /* OK, time to rat on our buddy... */
-
+ /*
+ * OK, time to rat on our buddy...
+ * See Documentation/RCU/stallwarn.txt for info on how to debug
+ * RCU CPU stall warnings.
+ */
printk(KERN_ERR "INFO: %s detected stalls on CPUs/tasks: {",
rsp->name);
rcu_for_each_leaf_node(rsp, rnp) {
@@ -517,6 +520,11 @@ static void print_cpu_stall(struct rcu_state *rsp)
unsigned long flags;
struct rcu_node *rnp = rcu_get_root(rsp);
+ /*
+ * OK, time to rat on ourselves...
+ * See Documentation/RCU/stallwarn.txt for info on how to debug
+ * RCU CPU stall warnings.
+ */
printk(KERN_ERR "INFO: %s detected stall on CPU %d (t=%lu jiffies)\n",
rsp->name, smp_processor_id(), jiffies - rsp->gp_start);
trigger_all_cpu_backtrace();