Re: [RFC] convert ftrace syscall tracer to TRACE_EVENT()

Mathieu Desnoyers
2009-05-09T15:57:54Z

* Frank Ch. Eigler (fche@redhat.com) wrote:
> Hi -
>
> On Sat, May 09, 2009 at 10:37:37AM +0200, Ingo Molnar wrote:
> > [...]
> > Firstly, it adds two new tracepoints to every system call. That is
> > unnecessary - we already have the TIF flag based callbacks, and we
> > can use the existing syscall attributes table to get to tracepoints
> > - without slow down (or impacting) the fast path in any way.
> > [...]
>
> However, as the TIF_SYSCALL_FTRACE and/or TIF_SYSCALL_TRACE flags are
> tied to a single consumer, it would limit the usefulness of the
> naturally multiple-client tracepoints, if they were made conditional
> on them. Would you be interested in a proper reference-counting API?
>

I've got this in my TIF_KERNEL_TRACE patchset. I think I should post it
as-is for RFC once more.

Mathieu

> - FChE

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Mathieu Desnoyers
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