Messages in this thread | | | Date | Fri, 27 Apr 2018 10:00:48 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH RFC] tracepoint: Introduce tracepoint callbacks executing with preempt on |
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On Fri, Apr 27, 2018 at 12:46:41PM -0400, Steven Rostedt wrote: > On Fri, 27 Apr 2018 09:45:54 -0700 > "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote: > > > > > That shouldn't be needed. For the rcu_read_lock_sched case, there is a > > > > preempt_disable which needs to be a notrace, but for the srcu one, > > > > since we don't do that, I think it should be fine. > > > > > > Actually, I think I may agree here too. Because the _notrace is for > > > function tracing, and it shouldn't affect it. If people don't want it > > > traced, they could add those functions to the list in the notrace file. > > > > OK, feel free to ignore my notrace srcu_read_lock() patch, then. ;-) > > Of course I wasn't thinking about the lockdep tracepoints that Joel > mentioned, which happens to be the reason for all this discussion in > the first place :-) Now I think we do need it. (OK, I can keep > changing my mind, can't I?).
You can, but at some point I start applying heavy-duty hysteresis. ;-)
So the current thought (as of your having sent the above email) is that we need notrace versions of srcu_read_lock() and srcu_read_unlock(), but not for __srcu_read_lock() and __srcu_read_unlock(), correct?
Thanx, Paul
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