Re: [Intel-gfx] [PATCH 47/51] drm/i915/selftest: Increase some timeouts in live_requests

Tvrtko Ursulin
2021-07-22T08:13:50Z

On 16/07/2021 21:17, Matthew Brost wrote:
> Requests may take slightly longer with GuC submission, let's increase
> the timeouts in live_requests.

Hm "slightly" ends up 5x longer here and one second feels a lot.

Out of curiosity, given this is about a simple submit of a no-op batches
in a tight loop, where does the huge amount of extra latency come from?
Is it single H2G channel shared for all engines, the firmware, or GuC
speed itself?

Regards,

Tvrtko

> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
> drivers/gpu/drm/i915/selftests/i915_request.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
> index bd5c96a77ba3..d67710d10615 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_request.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_request.c
> @@ -1313,7 +1313,7 @@ static int __live_parallel_engine1(void *arg)
> i915_request_add(rq);
>
> err = 0;
> - if (i915_request_wait(rq, 0, HZ / 5) < 0)
> + if (i915_request_wait(rq, 0, HZ) < 0)
> err = -ETIME;
> i915_request_put(rq);
> if (err)
> @@ -1419,7 +1419,7 @@ static int __live_parallel_spin(void *arg)
> }
> igt_spinner_end(&spin);
>
> - if (err == 0 && i915_request_wait(rq, 0, HZ / 5) < 0)
> + if (err == 0 && i915_request_wait(rq, 0, HZ) < 0)
> err = -EIO;
> i915_request_put(rq);