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Commit 8cdd32a9 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

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: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 9079fd7c

kernel/rcutree.c

+10 −2
Original line number Diff line number Diff line
@@ -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();