20 Jun
2014
20 Jun
'14
11:27 a.m.
I tried 10 times running 15 seconds and out of that 3 times I got output without any P-state information.
--
Thanks,
Salman Ahmed
On Friday, 20 June 2014, 16:49, Amit Kucheria amit.kucheria@linaro.org wrote:
On Fri, Jun 20, 2014 at 4:01 PM, Salman Ahmed salmanyam@yahoo.com wrote:
> Hello Amit,
>
> Actually, I ran it on the same machine with the same command again and these time the output has frequency information-
>
> $ sudo ./idlestat --trace -t 5 -f /tmp/myoutput -- top
>
> Log is 4.999547 secs long with 710 events
> clusterA@state hits total(us) avg(us) min(us) max(us)
> C6-SNB 174 4953094.00 28466.06 0.00 183909.00
> cpu0@state hits total(us) avg(us) min(us) max(us)
> C1-SNB 1 630.00 630.00 630.00 630.00
> C6-SNB 111 4995205.00 45001.85 8.00 279064.00
> cpu0 wakeups name count
> irq040 eth0 50
> cpu1@state hits total(us) avg(us) min(us) max(us)
> C6-SNB 54 4997809.00 92552.02 125.00 323888.00
> cpu1 wakeups name count
> irq018 ata_piix 10
> cpu2@state hits total(us) avg(us) min(us) max(us)
> C1-SNB 35 19993.00 571.23 121.00 11699.00
> C6-SNB 48 4957068.00 103272.25 51.00 323891.00
> 3101 8 487.00 60.88 1.00 291.00
> 1600 78 14303.00 183.37 1.00 6144.00
> cpu2 wakeups name count
> cpu3@state hits total(us) avg(us) min(us) max(us)
> C1-SNB 4 379.00 94.75 25.00 128.00
> C6-SNB 59 4997441.00 84702.39 60.00 323878.00
> cpu3 wakeups name count
>
> So, output sometimes contains frequency information and sometimes it doesn't with the same command. When it does not, trace file does not contain any cpu_frequency entry. So, the problem may not be with idlestat tool since it just parses trace file. Is it possible there is any bug in kernel tracing code?
>
Does this happen when you run for longer than 5 seconds? Try running
it for 15 seconds 10 times. I wonder if your platform isn't
transitioning P-states in 5 seconds.