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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-08-09 14:23:03 -0700 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-08-20 09:00:11 -0700 |
commit | 8cdd32a918350430483751feaae1c19cef816f69 (patch) | |
tree | b219bf5daf42a5fa0b48caf8b94174be2aa9a63f /kernel/rcutree.c | |
parent | 9079fd7c2e06a92cf27d05224a1f478581916c5b (diff) | |
download | lwn-8cdd32a918350430483751feaae1c19cef816f69.tar.gz lwn-8cdd32a918350430483751feaae1c19cef816f69.zip |
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.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 5aab7dabd0d5..ff214118e4b8 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(); |