Re: [Xenomai] filter ipipe tracing

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2014-01-14 18:30, David wrote:
> OK thanks, it helps to reduce by two factor (div 2) the number of trace per
> milliseconds ; more importantly is CPU usage lowered from 100% down to 50%.
> On a trace of 100000 points, i reached 250ms. 25% of these tracepoints are
> __ipipe_syscall_root+xxx that does not mean anything to me, but all
> syscalls, scheduling decisions and interrupts are visible.
> 
> The resulting trace contains tracepoints on the current CPU that activates
> the trace freeze. Is there a way to activate the simultaneous trace capture
> on two+ cores ?
> 
> I see trace_mark(...info...) in the Xenomai code. I don't think this info
> is displayed in ipipe trace, am I wrong ?

No, trace_mark are dead remainders of LTTng support. I'm slowly
converting them to ftrace tracepoints that you can then retrieve and
visualize with standard tools. It's an x86-64-only endeavor so far,
artifacts can be found in [1] for Xenomai 2 (on maintenance now). For
Xenomai 3, I didn't push anything yet.

Jan

[1] http://git.xenomai.org/xenomai-jki.git/log/?h=queues/ftrace

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