Re: Tracing of power:power_start events doesn't work

From: Ronny Tschüter
Date: Wed May 05 2010 - 02:34:35 EST


On Wed 2010-05-05 02:31, Steven Rostedt wrote:
On Mon, 2010-05-03 at 15:19 +0200, Ronny Tschüter wrote:
Hello,

i use kernel version 2.6.33.2 (x86-64, Core 2 Duo) and the perf events
to track frequency and c states of my cpu. But if i want to trace
power:power_start events, it does not work. After typing

echo "power:power_start" | sudo tee set_event

on the console, the trace doesn't contain such events.
power:power_frequency and power:power_end events are reported correctly
by the system. I read in the mailing list that Robert Schoene had a
similiar problem, but with power:power_end events. Is there a known bug
regarding to trace_power_start methods in process.c?
Is this for perf or ftrace? I'm assuming you did this from the debugfs
tracing directory. The set_event file is for ftrace not perf.
It is for perf - i'm interested in event tracing. I used the event tracing system like it is described in Documentation/trace/events.txt. In addition i wrote a program which uses syscall(__NR_perf_counter_open, ... ) to trace power events. But the result is the same - power:power_end events are reported, power:power_start events not.

Bye Ronny
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