On 11/18/14, 10:31 AM, Jerome Correnoz wrote:
> Jerome Correnoz <jerome.correnoz <at> st.com> writes:
>
>>
>> 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) ?


Not exactly what you want but might be close:

   git clone https://github.com/dsahern/linux
   git checkout perf-full-monty
   make -C tools/perf

perf sched record -ag -- sleep 1
perf sched timehist -S

shows the grains of sand (each sample) and then a runtime summary byt 
task. Example report attached for box just running a few VMs.

David