Messages in this thread | | | Date | Mon, 23 Sep 2002 00:59:15 +0200 (CEST) | From | Ingo Molnar <> | Subject | Re: [PATCH] LTT for 2.5.38 1/9: Core infrastructure |
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On Sun, 22 Sep 2002, Karim Yaghmour wrote:
> Ingo Molnar wrote: > > +int trace_event(u8 pm_event_id, > > + void *pm_event_struct) > > [...] > > + read_lock(&tracer_register_lock); > > > > ie. it's using a global spinlock. (sure, it can be made lockless, as other > > tracers have done it.) > > It is, but this is separate from the trace driver. [...]
it does not matter, it's called for every event.
> [...] This global spinlock is only used to avoid a race condition in the > registration/ unregistration of the tracing function with the trace > infrastructure.
(here you make the incorrect assumption that read-locking a rwlock is a lightweight operation.)
Ingo
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