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

Roman Zippel
2006-09-17T17:27:21Z

Hi,

On Mon, 18 Sep 2006, Nick Piggin wrote:

> > > > The foremost issue is still that there is only limited kprobes support.
> > >
> > > > The main issue in supporting static tracers are the tracepoints and so
> > > > far I haven't seen any convincing proof that the maintainance overhead
> > > > of dynamic and static tracepoints has to be significantly different.
>
> Above, weren't you asking about static vs dynamic trace-*points*, rather
> than the implementation of the tracer itself. I think Ingo said that
> some "static tracepoints" (eg. annotation) could be acceptable.

No, he made it rather clear, that as far as possible he only wants dynamic
annotations (e.g. via function attributes).

> > What you basically tell me is (rephrased to make it more clear): Implement
> > kprobes support or fuck off! You make it very clear, that you're unwilling
> > to support static tracers even to point to make _any_ static trace support
>
> Now it seems you are talking about compiled vs runtime inserted traces,
> which is different. And so far I have to agree with Ingo: dynamic seems
> to be better in almost every way. Implementation may be more complex,
> but that's never stood in the way of a better solution before, and I
> don't think anybody has shown it to be prohibitive ("I won't implement
> it" notwithstanding)

I don't deny that dynamic tracer are more flexible, but I simply don't
have the resources to implement one. If those who demand I use a dynamic
tracer, would also provide the appropriate funding, it would change the
situation completely, but without that I have to live with the tools
available to me.

bye, Roman