On Wed, Jul 11, 2018 at 09:00:03AM -0400, Steven Rostedt wrote:
On Wed, 11 Jul 2018 14:49:54 +0200 Peter Zijlstra peterz@infradead.org wrote:
On Thu, Jun 28, 2018 at 11:21:46AM -0700, Joel Fernandes wrote:
it_func_ptr = rcu_dereference_sched((tp)->funcs); \I would convert to rcu_dereference_raw() to appease sparse. The fancy stuff below is pointless if you then turn off all checking.
The problem with doing this is if we use a trace event without the proper _idle() or whatever, we wont get a warning that it is used incorrectly with lockdep. Or does lockdep still check if "rcu is watching" with rcu_dereference_raw()?
No lockdep checking is done by rcu_dereference_raw().
Thanx, Paul
-- Steve
\/* \* For rcuidle callers, use srcu since sched-rcu \* doesn't work from the idle path. \*/ \if (rcuidle) { \if (in_nmi()) { \WARN_ON_ONCE(1); \return; /* no srcu from nmi */ \} \\idx = srcu_read_lock_notrace(&tracepoint_srcu); \it_func_ptr = \srcu_dereference_notrace((tp)->funcs, \&tracepoint_srcu); \/* To keep it consistent with !rcuidle path */ \preempt_disable_notrace(); \} else { \rcu_read_lock_sched_notrace(); \it_func_ptr = \rcu_dereference_sched((tp)->funcs); \} \
-- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html