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

["Jose R. Santos" <jrs@us.ibm.com>]

Frank Ch. Eigler wrote:
> "Martin J. Bligh" <mbligh@mbligh.org> writes:
>
> > without all the awk-style language crap that seems to come with
> > systemtap.
>
> I'm sorry to hear you dislike the scripting language.  But that's
> okay, you Real Men can embed literal C code inside systemtap scripts
> to do the Real Work, and leave to systemtap only sundry duties such as
> probe placement and removal.
>   

There are also a couple of projects within SystemTap that provide trace 
like functionality without the need to use the SystemTap language.  In 
the case of LKET, we've tried to make this as simple as possible by 
predefining probe points using the SystemTap language and embedded C 
code, but from a users perspective all he really need to do is just 
invoke a simple script like:

#! stap
process_snapshot() {}
addevent.tskdispatch.cpuidle {}
addevent.process {}
addevent.syscall.entry { printf ("%4b", $flags) }
addevent.syscall.exit {}
addevent.tskdispatch.cpuidle {}

The data can later be analyses in user-space with what ever method you like.  The developer instrumenting the probe point needs to know the Systemtap language, but the user of the trace just need to know which events are available to him.

We also plan to do static tracing once SystemTap supports static markers.  This may not be the perfect solution, but I'm interested in knowing how we can get there.

-JRS