oprofile and ARM A9 hardware counter

[Måns Rullgård]

stephane eranian <eranian at googlemail.com> writes:

> Same result for me on CPU1:
>
> top - 16:20:24 up  1:45,  1 user,  load average: 0.29, 0.08, 0.07
> Tasks:  70 total,   2 running,  68 sleeping,   0 stopped,   0 zombie
> Cpu(s): 30.7%us,  2.7%sy,  0.0%ni, 66.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
> Mem:    940232k total,   228984k used,   711248k free,    82244k buffers
> Swap:   524240k total,        0k used,   524240k free,    91400k cached
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  P COMMAND
>  3968 eranian   20   0   644  160  128 R  100  0.0   0:21.98 1 noploop
>  3969 eranian   20   0  2184 1056  804 R    3  0.1   0:00.53 0 top
>    82 root      20   0     0    0    0 S    1  0.0   0:01.35 0
> kworker/0:1
>
> With 3.3.0-rc1, if I revert the clockdomain patch, I get the same result.
> So it must be coming from somewhere else, as you suggested.
>
> If the processor was spending time processing interrupts, then this would be
> accounted for in as sys time. But that's not what I observe here. It's either
> idle or user. That line, leads me to believe that the processor can only run
> my program for 30% of the time. The rest is spent idling even though my
> program is non-blocking. How could that be possible? Power-saving?

In top, press 1 to see the statistics for the CPUs separately.

-- 
Måns Rullgård
mans at mansr.com