Re: [patch 06/16] Markers auto enable tracepoints (new API : trace_mark_tp())

Ingo Molnar
2008-11-16T07:59:59Z

* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:

> Add a new API trace_mark_tp(), which declares a marker within a
> tracepoint probe. When the marker is activated, the tracepoint is
> automatically enabled.
>
> No branch test is used at the marker site, because it would be a
> duplicate of the branch already present in the tracepoint.
>
> Impact: new API.

i dont know.

I was actually hoping for markers (the in-kernel API) to go away
completely - and be replaced with tracepoints.

Markers are the wrong design on several levels. They couple the kernel
dynamically with unknown (to the kernel) entities - and that is
causing complexity all around the place, clearly expressed in these
patches of yours.

Tracepoints are much more specific - typed and enumerated function
call callback points in essence - with some politeness that allows
external instrumentation entities to attach to those callbacks.

Is there any usecase of markers that should not be converted to either
tracepoints or to ftrace_printk() ?

Ingo