Re: [PATCH] tracer for sys_open() - sreadahead

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Wed, Jan 28, 2009 at 02:58:28PM +0100, Frédéric Weisbecker escreveu:
> 2009/1/28 Frank Ch. Eigler <fche@redhat.com>:
> > Frederic Weisbecker <fweisbec@gmail.com> writes:
> >
> >> [...]
> >> Speaking about a global syscall tracer, I made a patch to trace only the syscalls
> >> with the function-graph-tracer.
> >> http://lkml.org/lkml/2008/12/30/267 This low-level part can easily
> >> be used by all tracers that would like to inspect syscalls.
> >> [...]
> >> Just a change is needed: Steven requested that the part inside
> >> syscall_trace_enter become a tracepoint, making it totally shareable
> >> between tracers and easy to turn on and off.
> >
> > Alternately, you could just rely on utrace's hooks.  They were thought
> > out more fully with respect to parameter access, manipulation, and
> > programmatic control befitting even a debugger.
> >
> >
> > - FChE
> >
> 
> I don't know much it. But I will soon have some time to look at your
> patch which uses ftrace from utrace.
> Anyway, are there some plans about utrace to be merged? Unless I
> couldn't be able to use
> it...

Well, one of the reasons for utrace not to be merged, IIRC, was that
there would be no users in-kernel. With Frank's ftrace plugin that is
not true anymore.

- Arnaldo