Re: [PATCH 0/11] LTTng-core (basic tracing infrastructure) 0.5.108

Ingo Molnar
2006-09-15T18:31:42Z

* Frank Ch. Eigler <fche@redhat.com> wrote:

> > Why are your despatching overheads 1000 cycles ? (and if its due to
> > int3 why are you using int 3 8))
>
> Smart teams from IBM and Hitachi have been hammering away at this code
> for a year or two now, and yet (roughly) here we are. There have been
> experiments involving plopping branches instead of int3's at probe
> locations, but this is self-modifying code involving multiple
> instructions, and appears to be tricky on SMP/preempt boxes.

i am talking to them about that, and i'm 100% sure the solution is much
easier than the many (much harder) problems that SystemTap has already
solved. I think you are way too modest to realize how powerful (and
important) SystemTap is :-)

Ingo