[Intel-gfx] [PATCH 5/9] drm/i915/selftests: Exercise some AB...BA preemption chains

[Tvrtko Ursulin]

On 29/01/2019 10:59, Chris Wilson wrote:
> Build a chain using 2 contexts (A, B) then request a preemption such
> that a later A request runs before the spinner in B.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/selftests/intel_lrc.c | 103 +++++++++++++++++++++
>   1 file changed, 103 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c
> index 58f534a39118..fe58ad711e2f 100644
> --- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
> @@ -4,6 +4,8 @@
>    * Copyright © 2018 Intel Corporation
>    */
>   
> +#include <linux/prime_numbers.h>
> +
>   #include "../i915_reset.h"
>   
>   #include "../i915_selftest.h"
> @@ -405,6 +407,106 @@ static int live_suppress_preempt(void *arg)
>   	goto err_client_b;
>   }
>   
> +static int live_chain_preempt(void *arg)
> +{
> +	struct drm_i915_private *i915 = arg;
> +	struct intel_engine_cs *engine;
> +	struct preempt_client hi, lo;
> +	enum intel_engine_id id;
> +	intel_wakeref_t wakeref;
> +	int err = -ENOMEM;
> +
> +	/*
> +	 * Build a chain AB...BA between two contexts (A, B) and request
> +	 * preemption of the last request. It should then complete before
> +	 * the previously submitted spinner in B.
> +	 */
> +
> +	if (!HAS_LOGICAL_RING_PREEMPTION(i915))
> +		return 0;
> +
> +	mutex_lock(&i915->drm.struct_mutex);
> +	wakeref = intel_runtime_pm_get(i915);
> +
> +	if (preempt_client_init(i915, &hi))
> +		goto err_unlock;
> +
> +	if (preempt_client_init(i915, &lo))
> +		goto err_client_hi;
> +
> +	for_each_engine(engine, i915, id) {
> +		struct i915_sched_attr attr = {
> +			.priority = I915_USER_PRIORITY(I915_PRIORITY_MAX),
> +		};
> +		int count, i;
> +
> +		for_each_prime_number_from(count, 1, 32) { /* must fit ring! */
> +			struct i915_request *rq;
> +
> +			rq = igt_spinner_create_request(&hi.spin,
> +							hi.ctx, engine,
> +							MI_ARB_CHECK);
> +			if (IS_ERR(rq))
> +				goto err_wedged;
> +			i915_request_add(rq);
> +			if (!igt_wait_for_spinner(&hi.spin, rq))
> +				goto err_wedged;
> +
> +			rq = igt_spinner_create_request(&lo.spin,
> +							lo.ctx, engine,
> +							MI_ARB_CHECK);
> +			if (IS_ERR(rq))
> +				goto err_wedged;
> +			i915_request_add(rq);
> +
> +			for (i = 0; i < count; i++) {
> +				rq = i915_request_alloc(engine, lo.ctx);
> +				if (IS_ERR(rq))
> +					goto err_wedged;
> +				i915_request_add(rq);
> +			}
> +
> +			rq = i915_request_alloc(engine, hi.ctx);
> +			if (IS_ERR(rq))
> +				goto err_wedged;
> +			i915_request_add(rq);
> +			engine->schedule(rq, &attr);
> +
> +			igt_spinner_end(&hi.spin);
> +			if (i915_request_wait(rq, I915_WAIT_LOCKED, HZ / 5) < 0) {
> +				struct drm_printer p =
> +					drm_info_printer(i915->drm.dev);
> +
> +				pr_err("Failed to preempt over chain of %d\n",
> +				       count);
> +				intel_engine_dump(engine, &p,
> +						  "%s\n", engine->name);
> +				goto err_wedged;
> +			}
> +			igt_spinner_end(&lo.spin);
> +		}
> +	}
> +
> +	err = 0;
> +err_client_lo:
> +	preempt_client_fini(&lo);
> +err_client_hi:
> +	preempt_client_fini(&hi);
> +err_unlock:
> +	if (igt_flush_test(i915, I915_WAIT_LOCKED))
> +		err = -EIO;
> +	intel_runtime_pm_put(i915, wakeref);
> +	mutex_unlock(&i915->drm.struct_mutex);
> +	return err;
> +
> +err_wedged:
> +	igt_spinner_end(&hi.spin);
> +	igt_spinner_end(&lo.spin);
> +	i915_gem_set_wedged(i915);
> +	err = -EIO;
> +	goto err_client_lo;
> +}
> +
>   static int live_preempt_hang(void *arg)
>   {
>   	struct drm_i915_private *i915 = arg;
> @@ -785,6 +887,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
>   		SUBTEST(live_preempt),
>   		SUBTEST(live_late_preempt),
>   		SUBTEST(live_suppress_preempt),
> +		SUBTEST(live_chain_preempt),
>   		SUBTEST(live_preempt_hang),
>   		SUBTEST(live_preempt_smoke),
>   	};
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko