[igt-dev] [PATCH i-g-t 1/2] i915/gem_exec_latency: Normalize results into ns

[Antonio Argenziano]

On 29/01/19 10:01, Chris Wilson wrote:
> Quoting Antonio Argenziano (2019-01-29 17:55:45)
>>
>>
>> On 29/01/19 01:55, Chris Wilson wrote:
>>> Present the latency results in nanoseconds not RCS cycles.
>>>
>>> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>>> ---
>>>    tests/i915/gem_exec_latency.c | 38 +++++++++++++++++++++++++++++++----
>>>    1 file changed, 34 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/tests/i915/gem_exec_latency.c b/tests/i915/gem_exec_latency.c
>>> index de16322a6..ea44adc14 100644
>>> --- a/tests/i915/gem_exec_latency.c
>>> +++ b/tests/i915/gem_exec_latency.c
>>> @@ -59,6 +59,7 @@
>>>    #define PREEMPT 0x2
>>>    
>>>    static unsigned int ring_size;
>>> +static double rcs_clock;
>>>    
>>>    static void
>>>    poll_ring(int fd, unsigned ring, const char *name)
>>> @@ -207,7 +208,7 @@ static void latency_on_ring(int fd,
>>>                igt_cork_unplug(&c);
>>>    
>>>        gem_set_domain(fd, obj[1].handle, I915_GEM_DOMAIN_GTT, 0);
>>> -     gpu_latency = (results[repeats-1] - results[0]) / (double)(repeats-1);
>>> +     gpu_latency = (results[repeats-1] - results[1]) / (double)(repeats-2);
>>
>> How come you don't like the value at 0? Maybe adding a comment would
>> make it clearer.
> 
> I was thinking of trying to reduce some context warmup latency, but
> it doesn't matter and the spinner in the second patch is much more
> effective overall.

OK.

Sorry for the long delay, it ended-up in my spam folder. If you still 
need it, the series is:

Reviewed-by: Antonio Argenziano <antonio.argenziano at intel.com>


> -Chris
>