On Thu, 18 Feb 2021 09:00:12 -0800 "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote: > OK, I will bite. ;-) Do I turn into a wearwolf? > > Can the saving of console into trace buffers be easily enabled and > disabled within the code? Well, we do have this for ftrace: echo 'enable_event:printk:console' > events/rcu/rcu_stall_warning/trigger Would enable the printk console to be traced to the ring buffer once the stall is triggered, and not before hand. > If so, does enabling and disabling nest? It has a disable as well, but unfortunately its global and does not nest. We could always implement a percpu trigger that can nest though. -- Steve
