Messages in this thread | | | Date | Mon, 23 Apr 2018 17:22:44 -0400 | From | Steven Rostedt <> | Subject | Re: [RFC v4 3/4] irqflags: Avoid unnecessary calls to trace_ if you can |
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On Mon, 23 Apr 2018 13:12:21 -0400 (EDT) Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> I'm inclined to explicitly declare the tracepoints with their given > synchronization method. Tracepoint probe callback functions for currently > existing tracepoints expect to have preemption disabled when invoked. > This assumption will not be true anymore for srcu-tracepoints.
Actually, why not have a flag attached to the tracepoint_func that states if it expects preemption to be enabled or not? If a trace_##event##_srcu() is called, then simply disable preemption before calling the callbacks for it. That way if a callback is fine for use with srcu, then it would require calling
register_trace_##event##_may_sleep();
Then if someone uses this on a tracepoint where preemption is disabled, we simply do not call it.
-- Steve
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