From 097de9f48860ae2d4c54d0810b1369affa06de61 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 22 May 2013 02:41:36 -0700 Subject: [PATCH] trace: Allow idle-safe tracepoints to be called from irq __DECLARE_TRACE_RCU() currently creates an _rcuidle() tracepoint which may safely be invoked from what RCU considers to be an idle CPU. However, these _rcuidle() tracepoints may -not- be invoked from the handler of an irq taken from idle, because rcu_idle_enter() zeroes RCU's nesting-level counter, so that the rcu_irq_exit() returning to idle will trigger a WARN_ON_ONCE(). This commit therefore substitutes rcu_irq_enter() for rcu_idle_exit() and rcu_irq_exit() for rcu_idle_enter() in order to make the _rcuidle() tracepoints usable from irq handlers as well as from process context. Reported-by: Dave Jones Signed-off-by: Paul E. McKenney Cc: Steven Rostedt --- include/linux/tracepoint.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 2f322c38bd4d61..f8e084d0fc772a 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -145,8 +145,8 @@ static inline void tracepoint_synchronize_unregister(void) TP_PROTO(data_proto), \ TP_ARGS(data_args), \ TP_CONDITION(cond), \ - rcu_idle_exit(), \ - rcu_idle_enter()); \ + rcu_irq_enter(), \ + rcu_irq_exit()); \ } #else #define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args)