Hello TraceCompass experts,
I have instrumented my embedded application with lttng-ust,
adding 4 tracepoints without arguments (a1, a2, a3, a4). My
app is running on a Linux 3.14.70 ARM board, and I'm using
lttng 2.6.0 "Gaia". I'm uploading the data to an Ubuntu host.
On the host, I can run babeltrace to get the raw tracing data.
Now I'd like to get some statistics about the time my app
takes between a1->a2, a2->a3, etc. I'd like to see the
min/max, navigate to the min/max, graph latency over time and
see a histogram of latency distribution. Similar to the System
Call Latency Views in Trace Compass.
I was hoping that I could write such an analysis in Python,
deriving from the lttng-analyses. So I've tried that on a
Kernel trace on my ARM board first (lttng-analyses-record ,
version v0.6.1). But uploading the Kernel trace to the host
and running a simple command like "lttng-cputop-mi mytrace"
just thinks a while and then prints
{"error-message": "Error: Cannot run analysis: 'State'
object has no attribute 'tracer_version'"}
My questions:
- Is it a reasonable approach writing an external analysis
for my lttng-ust in Python? Or is there any simpler /
better way getting the latency statistics that I want?
- Any clue what I could do to get lttng-analyses to work
in my environment?
- How could I move on getting the latency statistics?
Thanks a lot for any hints!
Martin
