Commit 38b237ea authored by Chris Wilson's avatar Chris Wilson Committed by Daniel Vetter
Browse files

drm/i915: Individual request cancellation 



Currently, we cancel outstanding requests within a context when the
context is closed. We may also want to cancel individual requests using
the same graceful preemption mechanism.

v2 (Tvrtko):
 * Cancel waiters carefully considering no timeline lock and RCU.
 * Fixed selftests.

v3 (Tvrtko):
 * Remove error propagation to waiters for now.

v4 (Tvrtko):
 * Rebase for extracted i915_request_active_engine. (Matt)

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
[danvet: Resolve conflict because intel_engine_flush_scheduler is
still called intel_engine_flush_submission]
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210324121335.2307063-3-tvrtko.ursulin@linux.intel.com
parent 7dbc19da

drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c

+1 −0
Original line number Diff line number Diff line
@@ -279,6 +279,7 @@ int intel_engine_pulse(struct intel_engine_cs *engine) 
		mutex_unlock(&ce->timeline->mutex);

	}



	intel_engine_flush_submission(engine);

	intel_engine_pm_put(engine);

	return err;

}

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

+7 −2
Original line number Diff line number Diff line
@@ -470,6 +470,11 @@ static void reset_active(struct i915_request *rq, 
	ce->lrc.lrca = lrc_update_regs(ce, engine, head);

}



static bool bad_request(const struct i915_request *rq)

{

	return rq->fence.error && i915_request_started(rq);

}



static struct intel_engine_cs *

__execlists_schedule_in(struct i915_request *rq)

{
@@ -482,7 +487,7 @@ __execlists_schedule_in(struct i915_request *rq) 
		     !intel_engine_has_heartbeat(engine)))

		intel_context_set_banned(ce);



	if (unlikely(intel_context_is_banned(ce)))

	if (unlikely(intel_context_is_banned(ce) || bad_request(rq)))

		reset_active(rq, engine);



	if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
@@ -1208,7 +1213,7 @@ static unsigned long active_preempt_timeout(struct intel_engine_cs *engine, 
		return 0;



	/* Force a fast reset for terminated contexts (ignoring sysfs!) */

	if (unlikely(intel_context_is_banned(rq->context)))

	if (unlikely(intel_context_is_banned(rq->context) || bad_request(rq)))

		return 1;



	return READ_ONCE(engine->props.preempt_timeout_ms);

drivers/gpu/drm/i915/i915_request.c

+30 −3
Original line number Diff line number Diff line
@@ -33,7 +33,10 @@ 
#include "gem/i915_gem_context.h"

#include "gt/intel_breadcrumbs.h"

#include "gt/intel_context.h"

#include "gt/intel_engine.h"

#include "gt/intel_engine_heartbeat.h"

#include "gt/intel_gpu_commands.h"

#include "gt/intel_reset.h"

#include "gt/intel_ring.h"

#include "gt/intel_rps.h"
@@ -542,20 +545,22 @@ void __i915_request_skip(struct i915_request *rq) 
	rq->infix = rq->postfix;

}



void i915_request_set_error_once(struct i915_request *rq, int error)

bool i915_request_set_error_once(struct i915_request *rq, int error)

{

	int old;



	GEM_BUG_ON(!IS_ERR_VALUE((long)error));



	if (i915_request_signaled(rq))

		return;

		return false;



	old = READ_ONCE(rq->fence.error);

	do {

		if (fatal_error(old))

			return;

			return false;

	} while (!try_cmpxchg(&rq->fence.error, &old, error));



	return true;

}



void i915_request_mark_eio(struct i915_request *rq)
@@ -722,6 +727,28 @@ void i915_request_unsubmit(struct i915_request *request) 
	spin_unlock_irqrestore(&engine->active.lock, flags);

}



static void __cancel_request(struct i915_request *rq)

{

	struct intel_engine_cs *engine = NULL;



	i915_request_active_engine(rq, &engine);



	if (engine && intel_engine_pulse(engine))

		intel_gt_handle_error(engine->gt, engine->mask, 0,

				      "request cancellation by %s",

				      current->comm);

}



void i915_request_cancel(struct i915_request *rq, int error)

{

	if (!i915_request_set_error_once(rq, error))

		return;



	set_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags);



	__cancel_request(rq);

}



static int __i915_sw_fence_call

submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)

{

drivers/gpu/drm/i915/i915_request.h

+3 −1
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ struct i915_request * __must_check 
i915_request_create(struct intel_context *ce);



void __i915_request_skip(struct i915_request *rq);

void i915_request_set_error_once(struct i915_request *rq, int error);

bool i915_request_set_error_once(struct i915_request *rq, int error);

void i915_request_mark_eio(struct i915_request *rq);



struct i915_request *__i915_request_commit(struct i915_request *request);
@@ -356,6 +356,8 @@ void i915_request_submit(struct i915_request *request); 
void __i915_request_unsubmit(struct i915_request *request);

void i915_request_unsubmit(struct i915_request *request);



void i915_request_cancel(struct i915_request *rq, int error);



long i915_request_wait(struct i915_request *rq,

		       unsigned int flags,

		       long timeout)

drivers/gpu/drm/i915/selftests/i915_request.c

+201 −0
Original line number Diff line number Diff line
@@ -609,6 +609,206 @@ static int live_nop_request(void *arg) 
	return err;

}



static int __cancel_inactive(struct intel_engine_cs *engine)

{

	struct intel_context *ce;

	struct igt_spinner spin;

	struct i915_request *rq;

	int err = 0;



	if (igt_spinner_init(&spin, engine->gt))

		return -ENOMEM;



	ce = intel_context_create(engine);

	if (IS_ERR(ce)) {

		err = PTR_ERR(ce);

		goto out_spin;

	}



	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);

	if (IS_ERR(rq)) {

		err = PTR_ERR(rq);

		goto out_ce;

	}



	pr_debug("%s: Cancelling inactive request\n", engine->name);

	i915_request_cancel(rq, -EINTR);

	i915_request_get(rq);

	i915_request_add(rq);



	if (i915_request_wait(rq, 0, HZ / 5) < 0) {

		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);



		pr_err("%s: Failed to cancel inactive request\n", engine->name);

		intel_engine_dump(engine, &p, "%s\n", engine->name);

		err = -ETIME;

		goto out_rq;

	}



	if (rq->fence.error != -EINTR) {

		pr_err("%s: fence not cancelled (%u)\n",

		       engine->name, rq->fence.error);

		err = -EINVAL;

	}



out_rq:

	i915_request_put(rq);

out_ce:

	intel_context_put(ce);

out_spin:

	igt_spinner_fini(&spin);

	if (err)

		pr_err("%s: %s error %d\n", __func__, engine->name, err);

	return err;

}



static int __cancel_active(struct intel_engine_cs *engine)

{

	struct intel_context *ce;

	struct igt_spinner spin;

	struct i915_request *rq;

	int err = 0;



	if (igt_spinner_init(&spin, engine->gt))

		return -ENOMEM;



	ce = intel_context_create(engine);

	if (IS_ERR(ce)) {

		err = PTR_ERR(ce);

		goto out_spin;

	}



	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);

	if (IS_ERR(rq)) {

		err = PTR_ERR(rq);

		goto out_ce;

	}



	pr_debug("%s: Cancelling active request\n", engine->name);

	i915_request_get(rq);

	i915_request_add(rq);

	if (!igt_wait_for_spinner(&spin, rq)) {

		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);



		pr_err("Failed to start spinner on %s\n", engine->name);

		intel_engine_dump(engine, &p, "%s\n", engine->name);

		err = -ETIME;

		goto out_rq;

	}

	i915_request_cancel(rq, -EINTR);



	if (i915_request_wait(rq, 0, HZ / 5) < 0) {

		struct drm_printer p = drm_info_printer(engine->i915->drm.dev);



		pr_err("%s: Failed to cancel active request\n", engine->name);

		intel_engine_dump(engine, &p, "%s\n", engine->name);

		err = -ETIME;

		goto out_rq;

	}



	if (rq->fence.error != -EINTR) {

		pr_err("%s: fence not cancelled (%u)\n",

		       engine->name, rq->fence.error);

		err = -EINVAL;

	}



out_rq:

	i915_request_put(rq);

out_ce:

	intel_context_put(ce);

out_spin:

	igt_spinner_fini(&spin);

	if (err)

		pr_err("%s: %s error %d\n", __func__, engine->name, err);

	return err;

}



static int __cancel_completed(struct intel_engine_cs *engine)

{

	struct intel_context *ce;

	struct igt_spinner spin;

	struct i915_request *rq;

	int err = 0;



	if (igt_spinner_init(&spin, engine->gt))

		return -ENOMEM;



	ce = intel_context_create(engine);

	if (IS_ERR(ce)) {

		err = PTR_ERR(ce);

		goto out_spin;

	}



	rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);

	if (IS_ERR(rq)) {

		err = PTR_ERR(rq);

		goto out_ce;

	}

	igt_spinner_end(&spin);

	i915_request_get(rq);

	i915_request_add(rq);



	if (i915_request_wait(rq, 0, HZ / 5) < 0) {

		err = -ETIME;

		goto out_rq;

	}



	pr_debug("%s: Cancelling completed request\n", engine->name);

	i915_request_cancel(rq, -EINTR);

	if (rq->fence.error) {

		pr_err("%s: fence not cancelled (%u)\n",

		       engine->name, rq->fence.error);

		err = -EINVAL;

	}



out_rq:

	i915_request_put(rq);

out_ce:

	intel_context_put(ce);

out_spin:

	igt_spinner_fini(&spin);

	if (err)

		pr_err("%s: %s error %d\n", __func__, engine->name, err);

	return err;

}



static int live_cancel_request(void *arg)

{

	struct drm_i915_private *i915 = arg;

	struct intel_engine_cs *engine;



	/*

	 * Check cancellation of requests. We expect to be able to immediately

	 * cancel active requests, even if they are currently on the GPU.

	 */



	for_each_uabi_engine(engine, i915) {

		struct igt_live_test t;

		int err, err2;



		if (!intel_engine_has_preemption(engine))

			continue;



		err = igt_live_test_begin(&t, i915, __func__, engine->name);

		if (err)

			return err;



		err = __cancel_inactive(engine);

		if (err == 0)

			err = __cancel_active(engine);

		if (err == 0)

			err = __cancel_completed(engine);



		err2 = igt_live_test_end(&t);

		if (err)

			return err;

		if (err2)

			return err2;

	}



	return 0;

}



static struct i915_vma *empty_batch(struct drm_i915_private *i915)

{

	struct drm_i915_gem_object *obj;
@@ -1486,6 +1686,7 @@ int i915_request_live_selftests(struct drm_i915_private *i915) 
		SUBTEST(live_sequential_engines),

		SUBTEST(live_parallel_engines),

		SUBTEST(live_empty_request),

		SUBTEST(live_cancel_request),

		SUBTEST(live_breadcrumbs_smoketest),

	};