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

[Ingo Molnar <mingo@elte.hu>]

* Roman Zippel <zippel@linux-m68k.org> wrote:

> > > > Secondly, even people who intend to _eventually_ make use of 
> > > > tracing, dont use it most of the time. So why should they have 
> > > > more overhead when they are not tracing? Again: the point is not 
> > > > moot because even though the user intends to use tracing, but 
> > > > does not always want to trace.
> > > 
> > > I've used kernels which included static tracing and the perfomance 
> > > overhead is negligible for occasional use.
> > 
> > how does this suddenly make my point, that "a marker for dynamic 
> > tracing has lower performance impact than a static tracepoint, on 
> > systems that are not being traced", "moot"?
> 
> Why exactly is the point relevant in first place? How exactly is the 
> added (minor!) overhead such a fundamental problem?

how could a fundamental performance difference between two markup 
schemes be not relevant to kernel design decisions? Which performance 
difference i claim derives straight from the conceptual difference 
between the two approaches and is thus "unfixable" (and not an 
"implementational issue").

	Ingo