Re: [RFC] ktap: Another dynamic tracing tool for Linux

[Michel Dagenais <michel.dagenais@polymtl.ca>]

----- "Jovi Zhang" <bookjovi@gmail.com> wrote:
> On Fri, Jan 11, 2013 at 10:19 PM, Michel Dagenais
> <michel.dagenais@polymtl.ca> wrote:
> > You may be interested in KGTP which implements a simple bytecode interpreter
> > in the kernel to accept GDB tracepoints
> http://code.google.com/p/kgtp/
> >
> > The bytecode is quite limited but would be easy to extend.
> KGTP is still not meet my requirement on Linux tracing.
> ktap don't have gcc or gdb dependence, it's build from scratch, with a
> clean design, this is very important.

KGTP uses the GDB remote protocol but does not use/require GDB. If you have the needed information about symbols, offsets... you can generate and send the bytecode yourself. 

> > Eventually we should be able to connect LTTng http://lttng.org/ and KGTP in
> > order to benefit from the efficiency of LTTng for activating probes and
> > retrieving data.
> You are right, LTTng should be possible, and I already planed it, also
> on some functionality of ftrace and systemtap.

Such dynamic capabilities are definitely of interest both in kernel and userspace tracing.