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

Frank Ch. Eigler
2009-05-09T15:39:16Z

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?

- FChE