On Wed, Jul 11, 2018 at 09:06:49AM -0400, Steven Rostedt wrote:
On Wed, 11 Jul 2018 14:56:47 +0200 Peter Zijlstra peterz@infradead.org wrote:
On Thu, Jun 28, 2018 at 11:21:46AM -0700, Joel Fernandes wrote:
static inline void tracepoint_synchronize_unregister(void) {
- synchronize_srcu(&tracepoint_srcu); synchronize_sched();
}
Given you below do call_rcu_sched() and then call_srcu(), isn't the above the wrong way around?
Good catch!
release_probes() call_rcu_sched() ---> rcu_free_old_probes() queued
tracepoint_synchronize_unregister() synchronize_srcu(&tracepoint_srcu); < finishes right away > synchronize_sched() --> rcu_free_old_probes() --> srcu_free_old_probes() queued Here tracepoint_synchronize_unregister() returned before the srcu portion ran.
I just read the comment that goes with that function; the order doesn't matter. All we want to ensure is that the unregistration is visible to either sched or srcu tracepoint users. -- 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