From: Paul E. McKenney Date: Mon, 9 Aug 2010 21:23:03 +0000 (-0700) Subject: rcu: refer RCU CPU stall-warning victims to stallwarn.txt X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8cdd32a918350430483751feaae1c19cef816f69;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git 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 --- 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();