Hi,
I just had a discussion with Frank Ch. Eigler from the SystemTAP team on the
topic "how can the tools cooperate well together".
SystemTAP is especially made for running user defined scripts at specific points
in the kernel. I has the ability to add/remove scripts and instrumentation
dynamically from a running kernel.
LTTng is a kernel tracer designed to have the minimum impact on the system while
having a design solid enough that it can trace NMI handlers (no locking). It
supports native C types and alignment. It can register new instrumentation sites
from dynamically loaded modules on-the-fly.
LTTV is a modular text/graphical trace analysis tool. You can think of it as
framework offered for plugins to interact together to show information. Simple
plugins can show generically some information (detailed event list, for
instance), while more sophisticated plugins can show a particular representation
of the system (each process state (user mode, system call, interrupted,
in trap, ...) evolving through time).
While the SystemTAP project focus on pre-processing of the information, LTT
focus on raw data copy (limiting the impact at probe site) at the cost of more
data to be transferred and analysed afterward.
I think that both approaches are complementary. I am trying to see where
integrated analysis of pre-processed and post-processed information could be
interesting, but I'm sure there are areas where it is.
If you have application ideas, feel free to express yourself.