Is it possible to get (or compute) the consummed CPU with perf ?

[Jerome Correnoz <jerome.correnoz@st.com>]

Hi,

We're interested to know the CPU load/usage on our ARMv7 embedded system 
when running some use cases (e.g. simple video decode, double video 
decode, etc.). By CPU load, I mean a way to measure the time when the 
system was doing something else than Idle.

I've tried to get it from the performance counter statistics but couldn't 
find a way to get it, do I miss something ?

Also tried to use perf for profiling the system (e.g. perf record -a). It 
report very useful percentage for the running processes that we exploit to 
detect hot spots. But It reports X% of the used CPU (nothing related to 
Idle or "rest of CPU"). 

So, any way with perf to get this information (directly or indirectly with 
few calculation) ?

Thanks by advance,
  Jerome