From 0989cb46783188ea7346ba6490be0046b9b7a725 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 1 Nov 2011 08:57:21 -0700 Subject: rcu: Add more information to the wrong-idle-task complaint The current code just complains if the current task is not the idle task. This commit therefore adds printing of the identity of the idle task. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- kernel/rcutree.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'kernel/rcutree.c') diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 06e40dd53b23..9888a0ad2d4e 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -356,10 +356,14 @@ static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval) } trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting); if (!idle_cpu(smp_processor_id())) { - WARN_ON_ONCE(1); /* must be idle task! */ + struct task_struct *idle = idle_task(smp_processor_id()); + trace_rcu_dyntick("Error on entry: not idle task", oldval, rdtp->dynticks_nesting); ftrace_dump(DUMP_ALL); + WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s", + current->pid, current->comm, + idle->pid, idle->comm); /* must be idle task! */ } /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */ smp_mb__before_atomic_inc(); /* See above. */ @@ -445,10 +449,14 @@ static void rcu_idle_exit_common(struct rcu_dynticks *rdtp, long long oldval) WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1)); trace_rcu_dyntick("End", oldval, rdtp->dynticks_nesting); if (!idle_cpu(smp_processor_id())) { - WARN_ON_ONCE(1); /* must be idle task! */ + struct task_struct *idle = idle_task(smp_processor_id()); + trace_rcu_dyntick("Error on exit: not idle task", oldval, rdtp->dynticks_nesting); ftrace_dump(DUMP_ALL); + WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s", + current->pid, current->comm, + idle->pid, idle->comm); /* must be idle task! */ } } -- cgit v1.2.3-70-g09d2