[ltt-dev] simultaneous lttng kerner tracer and userspace tracer

[Mathieu Desnoyers]

* Holger brunck (holger.brunck at keymile.com) wrote:
> Hi,
> 
> On 06/10/2010 01:50 PM, MEKEZE KWATCHO, PATRICK (PATRICK) wrote:
> > 
> > Yes, I see well the kernel event and the testprogramm process when I analyze the trace1 get with $ lttctl -C -w /tmp/trace1 trace1
> > 
> > I also think that is it possible to start a userspace trace without using the usttrace tool.
> > When I run $usttrace ./testprogramm and $ lttctl -C -w /tmp/trace1 trace1, I saw on the lttv-gui all the kernel event, but i didn't see my userspace event.
> > Among the process, both usttrace and testprogramm are present.
> > 
> 
> hm, is the ltt_userspace_event kernel module loaded?

ltt_userspace_event is not needed for ust. It's only there to enable the
debugfs "write_event" file, where a userspace application can write a
string, which generated a userspace.event event. This is a "poor man's"
userspace tracer that saves the trace data within the kernel stream in
the "userspace" channel.

Thanks,

Mathieu

> 
> Regards
> Holger
> 
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com