[PATCH i-g-t] tests/intel/xe_drm_fdinfo: Increase sampling period

[Umesh Nerlige Ramappa]

On Thu, Nov 07, 2024 at 09:43:50PM -0800, Lucas De Marchi wrote:
>This reverts commit 4f79f059766c ("tests/intel/xe_drm_fdinfo: Half the
>execution time") and goes in the opposite direction, doubling it.
>Although in some machines we pass consistently, others like LNL
>show sporadic failures.
>
>Even after changes in the kernel to improve it, it still shows those
>failures. Also, the failures can be much more frequent by stressing all
>the CPUs. Raise the period to reduce the error introduced due to
>additional scheduling delays. This shows a good improvement on LNL that
>doesn't fail anymore without CPU load and fails once every ~200
>iterations with 100% CPU load (vs once every ~3 iterations).

LGTM.

Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>

On a related note, how do we let a dev know that the tests may fail 
occasionally due to scheduling delays, so that triaging future failures 
can happen in a more informed manner? A comment in the IGT test file?  
Thoughts?

Thanks,
Umesh

>
>Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
>---
> tests/intel/xe_drm_fdinfo.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/tests/intel/xe_drm_fdinfo.c b/tests/intel/xe_drm_fdinfo.c
>index 5fd7c0416..ef9273e2a 100644
>--- a/tests/intel/xe_drm_fdinfo.c
>+++ b/tests/intel/xe_drm_fdinfo.c
>@@ -82,7 +82,7 @@ struct pceu_cycles {
> 	uint64_t total_cycles;
> };
>
>-const unsigned long batch_duration_usec = (1 * USEC_PER_SEC) / 4;
>+const unsigned long batch_duration_usec = (1 * USEC_PER_SEC);
>
> static const char *engine_map[] = {
> 	"rcs",
>-- 
>2.47.0
>