Re: [PATCH v2] tracing/perf: Move rcu_irq_enter/exit_irqson() to perf trace point hook

From: Paul E. McKenney
Date: Tue Feb 11 2020 - 13:55:04 EST


On Tue, Feb 11, 2020 at 06:32:13PM +0100, Peter Zijlstra wrote:
> On Tue, Feb 11, 2020 at 06:29:52PM +0100, Peter Zijlstra wrote:
> > +#define trace_rcu_enter() \
> > +({ \
> > + unsigned long state = 0; \
> > + if (!rcu_is_watching()) { \
>
> Also, afaict rcu_is_watching() itself needs more love, the functio has
> notrace, but calls other stuff that does not have notrace or inline.

Good catch! Like this?

Thanx, Paul

------------------------------------------------------------------------

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1f5fdf7..51616e72 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -295,7 +295,7 @@ static void rcu_dynticks_eqs_online(void)
*
* No ordering, as we are sampling CPU-local information.
*/
-static bool rcu_dynticks_curr_cpu_in_eqs(void)
+static bool notrace rcu_dynticks_curr_cpu_in_eqs(void)
{
struct rcu_data *rdp = this_cpu_ptr(&rcu_data);