[LTP] [PATCH] syscalls/perf_event_open03: skip test on slower systems

[Cyril Hrubis]

Hi!
> Generally, this method looks good, but maybe better to limit this
> check_progress() only perform on -debug kernel?  Otherwise,

I guess that it may be pretty useful on embedded systems as well. Having
TCONF message with "system too slow" rather than a timeout sounds like
an improvement to me.

> Reviewed-by: Li Wang <liwang@redhat.com>
> 
> 
> ======= FYI ==========
> I'm seeking a fair way to make a global evaluation of the test
> system to reset timeout dynamically for the whole LTP.
> 
> My original design thoughts:
> 
>   Create the numbers of threads equal to CPUs and bind them to
>   the corresponding cpu for running. Use mutex lock to sync up
>   each thread launch at the same time to collect the basic data
>   for their CPU. Then we can compare the CPU state under the idle or
>   busy time to get a relatively stationary _value_ to measure the system
>   performance.
> 
> But so far the test method is not stable&reliable as expected.
> 
>   // do float computing + dirty 10*pagesz memory  in a limited times
>   one_unit_of_operation();
> 
>   // count the CPU looping numbers with (type = idel, calcu)
>   // and call one_unit_opertaion() in 1 sec
>   cpu_1sec_looping(int type);
> 
>   idlespeed_loops = cpu_1sec_looping(idel);
>   calculate_loops = cpu_1sec_looping(calcu);
>   ...
>   // count the _value_ from all CPU average loops
>   ratio = calculate_avg / idealspeed_avg;

I'm not sure how useful this would be, I guess that the speed of
different syscalls will differ quite a bit on different kernel versions.
Maybe the whole system is too complex and cannot be described by
something as simple as this. But I guess that we will not know unless we
try.

-- 
Cyril Hrubis
chrubis@suse.cz