[igt-dev] [i-g-t V3 1/2] lib/i915: find scheduler caps for timeslicing

[Tvrtko Ursulin]

On 31/05/2021 14:41, Tejas Upadhyay wrote:
> Check scheduler capability for timeslicing in appropriate
> way, which requires wrappers to be created for IGT.
> 
> V3:
>      removed conditional error - petri
> V2: has_timeslice = has_semaphore && has_preemption ||
>      has_guc_submission - Tvrtko
> 
> Signed-off-by: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay at intel.com>
> ---
>   lib/i915/gem_scheduler.c | 21 +++++++++++++++++++++
>   lib/i915/gem_scheduler.h |  1 +
>   2 files changed, 22 insertions(+)
> 
> diff --git a/lib/i915/gem_scheduler.c b/lib/i915/gem_scheduler.c
> index 184da843..f59c451f 100644
> --- a/lib/i915/gem_scheduler.c
> +++ b/lib/i915/gem_scheduler.c
> @@ -29,6 +29,7 @@
>   #include "ioctl_wrappers.h"
>   
>   #include "i915/gem_scheduler.h"
> +#include "i915/gem_submission.h"
>   
>   /**
>    * SECTION:gem_scheduler
> @@ -129,6 +130,22 @@ bool gem_scheduler_has_engine_busy_stats(int fd)
>   		I915_SCHEDULER_CAP_ENGINE_BUSY_STATS;
>   }
>   
> +/**
> + * gem_scheduler_has_timeslicing:
> + * @fd: open i915 drm file descriptor
> + *
> + * Feature test macro to query whether the driver supports using HW preemption
> + * to implement timeslicing of userspace batches. This allows userspace to
> + * implement micro-level scheduling within their own batches.
> + */
> +bool gem_scheduler_has_timeslicing(int fd)
> +{
> +	return ((gem_scheduler_capability(fd) &
> +	        (I915_SCHEDULER_CAP_PREEMPTION |
> +		 I915_SCHEDULER_CAP_SEMAPHORES))
> +		|| gem_has_guc_submission(fd));
> +}
> +
>   /**
>    * gem_scheduler_print_capability:
>    * @fd: open i915 drm file descriptor
> @@ -151,4 +168,8 @@ void gem_scheduler_print_capability(int fd)
>   		igt_info(" - With HW semaphores enabled\n");
>   	if (caps & I915_SCHEDULER_CAP_ENGINE_BUSY_STATS)
>   		igt_info(" - With engine busy statistics\n");
> +	if ((caps & (I915_SCHEDULER_CAP_PREEMPTION
> +		  | I915_SCHEDULER_CAP_SEMAPHORES))
> +		|| gem_has_guc_submission(fd))
> +		igt_info(" - With user timeslicing enabled\n");

I don't think it's "user timeslicing" but just timeslicing. Otherwise 
looks okay.

Regards,

Tvrtko

>   }
> diff --git a/lib/i915/gem_scheduler.h b/lib/i915/gem_scheduler.h
> index 14bd4cac..d43e84bd 100644
> --- a/lib/i915/gem_scheduler.h
> +++ b/lib/i915/gem_scheduler.h
> @@ -32,6 +32,7 @@ bool gem_scheduler_has_ctx_priority(int fd);
>   bool gem_scheduler_has_preemption(int fd);
>   bool gem_scheduler_has_semaphores(int fd);
>   bool gem_scheduler_has_engine_busy_stats(int fd);
> +bool gem_scheduler_has_timeslicing(int fd);
>   void gem_scheduler_print_capability(int fd);
>   
>   #endif /* GEM_SCHEDULER_H */
>