We already have one event notifier there - look at theBut that would basically mandate tracepoints to be always enabled, do we
perf_swcounter_event() callback. Why add a second one for essentially
the same thing?
We should only put a single callback there - a tracepoint defined via
TRACE_EVENT() - and any secondary users can register a callback to the
tracepoint itself.
There's many similar places in the kernel - with notifier chains and
also with a need to get tracepoints there. The fastest (and most
consistent) solution is to add just a single event callback facility.
want to go there?
I don't think the overhead of tracepoints is understood well enough,
Jason you poked at that, do you have anything solid on that?
Also, I can imagine the embedded people to not want that.
I really like perf and tracepoints to not become co-dependent until
tracepoint become mandatory for all configurations.