Re: [Intel-gfx] [PATCH 25/51] drm/i915: Move active request tracking to a vfunc

John Harrison
2021-07-20T20:05:23Z

On 7/16/2021 13:16, Matthew Brost wrote:
> Move active request tracking to a backend vfunc rather than assuming all
> backends want to do this in the maner. In the case execlists /
maner -> manner.
In the case *of* execlists

With those fixed...
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>

> ring submission the tracking is on the physical engine while with GuC
> submission it is on the context.
>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
> drivers/gpu/drm/i915/gt/intel_context.c | 3 ++
> drivers/gpu/drm/i915/gt/intel_context_types.h | 7 ++++
> drivers/gpu/drm/i915/gt/intel_engine_types.h | 6 +++
> .../drm/i915/gt/intel_execlists_submission.c | 40 ++++++++++++++++++
> .../gpu/drm/i915/gt/intel_ring_submission.c | 22 ++++++++++
> drivers/gpu/drm/i915/gt/mock_engine.c | 30 ++++++++++++++
> .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 33 +++++++++++++++
> drivers/gpu/drm/i915/i915_request.c | 41 ++-----------------
> drivers/gpu/drm/i915/i915_request.h | 2 +
> 9 files changed, 147 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
> index 251ff7eea22d..bfb05d8697d1 100644
> --- a/drivers/gpu/drm/i915/gt/intel_context.c
> +++ b/drivers/gpu/drm/i915/gt/intel_context.c
> @@ -393,6 +393,9 @@ intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
> spin_lock_init(&ce->guc_state.lock);
> INIT_LIST_HEAD(&ce->guc_state.fences);
>
> + spin_lock_init(&ce->guc_active.lock);
> + INIT_LIST_HEAD(&ce->guc_active.requests);
> +
> ce->guc_id = GUC_INVALID_LRC_ID;
> INIT_LIST_HEAD(&ce->guc_id_link);
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
> index 542c98418771..035108c10b2c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_context_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
> @@ -162,6 +162,13 @@ struct intel_context {
> struct list_head fences;
> } guc_state;
>
> + struct {
> + /** lock: protects everything in guc_active */
> + spinlock_t lock;
> + /** requests: active requests on this context */
> + struct list_head requests;
> + } guc_active;
> +
> /* GuC scheduling state flags that do not require a lock. */
> atomic_t guc_sched_state_no_lock;
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> index 03a81e8d87f4..950fc73ed6af 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> @@ -420,6 +420,12 @@ struct intel_engine_cs {
>
> void (*release)(struct intel_engine_cs *engine);
>
> + /*
> + * Add / remove request from engine active tracking
> + */
> + void (*add_active_request)(struct i915_request *rq);
> + void (*remove_active_request)(struct i915_request *rq);
> +
> struct intel_engine_execlists execlists;
>
> /*
> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index abe48421fd7a..f9b5f54a5abe 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -3106,6 +3106,42 @@ static void execlists_park(struct intel_engine_cs *engine)
> cancel_timer(&engine->execlists.preempt);
> }
>
> +static void add_to_engine(struct i915_request *rq)
> +{
> + lockdep_assert_held(&rq->engine->sched_engine->lock);
> + list_move_tail(&rq->sched.link, &rq->engine->sched_engine->requests);
> +}
> +
> +static void remove_from_engine(struct i915_request *rq)
> +{
> + struct intel_engine_cs *engine, *locked;
> +
> + /*
> + * Virtual engines complicate acquiring the engine timeline lock,
> + * as their rq->engine pointer is not stable until under that
> + * engine lock. The simple ploy we use is to take the lock then
> + * check that the rq still belongs to the newly locked engine.
> + */
> + locked = READ_ONCE(rq->engine);
> + spin_lock_irq(&locked->sched_engine->lock);
> + while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {
> + spin_unlock(&locked->sched_engine->lock);
> + spin_lock(&engine->sched_engine->lock);
> + locked = engine;
> + }
> + list_del_init(&rq->sched.link);
> +
> + clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
> + clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags);
> +
> + /* Prevent further __await_execution() registering a cb, then flush */
> + set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
> +
> + spin_unlock_irq(&locked->sched_engine->lock);
> +
> + i915_request_notify_execute_cb_imm(rq);
> +}
> +
> static bool can_preempt(struct intel_engine_cs *engine)
> {
> if (GRAPHICS_VER(engine->i915) > 8)
> @@ -3206,6 +3242,8 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
> engine->cops = &execlists_context_ops;
> engine->request_alloc = execlists_request_alloc;
> engine->bump_serial = execlist_bump_serial;
> + engine->add_active_request = add_to_engine;
> + engine->remove_active_request = remove_from_engine;
>
> engine->reset.prepare = execlists_reset_prepare;
> engine->reset.rewind = execlists_reset_rewind;
> @@ -3797,6 +3835,8 @@ execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
> "v%dx%d", ve->base.class, count);
> ve->base.context_size = sibling->context_size;
>
> + ve->base.add_active_request = sibling->add_active_request;
> + ve->base.remove_active_request = sibling->remove_active_request;
> ve->base.emit_bb_start = sibling->emit_bb_start;
> ve->base.emit_flush = sibling->emit_flush;
> ve->base.emit_init_breadcrumb = sibling->emit_init_breadcrumb;
> diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> index 61469c631057..3b1471c50d40 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> @@ -1052,6 +1052,25 @@ static void ring_bump_serial(struct intel_engine_cs *engine)
> engine->serial++;
> }
>
> +static void add_to_engine(struct i915_request *rq)
> +{
> + lockdep_assert_held(&rq->engine->sched_engine->lock);
> + list_move_tail(&rq->sched.link, &rq->engine->sched_engine->requests);
> +}
> +
> +static void remove_from_engine(struct i915_request *rq)
> +{
> + spin_lock_irq(&rq->engine->sched_engine->lock);
> + list_del_init(&rq->sched.link);
> +
> + /* Prevent further __await_execution() registering a cb, then flush */
> + set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
> +
> + spin_unlock_irq(&rq->engine->sched_engine->lock);
> +
> + i915_request_notify_execute_cb_imm(rq);
> +}
> +
> static void setup_common(struct intel_engine_cs *engine)
> {
> struct drm_i915_private *i915 = engine->i915;
> @@ -1069,6 +1088,9 @@ static void setup_common(struct intel_engine_cs *engine)
> engine->reset.cancel = reset_cancel;
> engine->reset.finish = reset_finish;
>
> + engine->add_active_request = add_to_engine;
> + engine->remove_active_request = remove_from_engine;
> +
> engine->cops = &ring_context_ops;
> engine->request_alloc = ring_request_alloc;
> engine->bump_serial = ring_bump_serial;
> diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
> index fc5a65ab1937..5f86ff79c98c 100644
> --- a/drivers/gpu/drm/i915/gt/mock_engine.c
> +++ b/drivers/gpu/drm/i915/gt/mock_engine.c
> @@ -235,6 +235,34 @@ static void mock_submit_request(struct i915_request *request)
> spin_unlock_irqrestore(&engine->hw_lock, flags);
> }
>
> +static void mock_add_to_engine(struct i915_request *rq)
> +{
> + lockdep_assert_held(&rq->engine->sched_engine->lock);
> + list_move_tail(&rq->sched.link, &rq->engine->sched_engine->requests);
> +}
> +
> +static void mock_remove_from_engine(struct i915_request *rq)
> +{
> + struct intel_engine_cs *engine, *locked;
> +
> + /*
> + * Virtual engines complicate acquiring the engine timeline lock,
> + * as their rq->engine pointer is not stable until under that
> + * engine lock. The simple ploy we use is to take the lock then
> + * check that the rq still belongs to the newly locked engine.
> + */
> +
> + locked = READ_ONCE(rq->engine);
> + spin_lock_irq(&locked->sched_engine->lock);
> + while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {
> + spin_unlock(&locked->sched_engine->lock);
> + spin_lock(&engine->sched_engine->lock);
> + locked = engine;
> + }
> + list_del_init(&rq->sched.link);
> + spin_unlock_irq(&locked->sched_engine->lock);
> +}
> +
> static void mock_reset_prepare(struct intel_engine_cs *engine)
> {
> }
> @@ -327,6 +355,8 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
> engine->base.emit_flush = mock_emit_flush;
> engine->base.emit_fini_breadcrumb = mock_emit_breadcrumb;
> engine->base.submit_request = mock_submit_request;
> + engine->base.add_active_request = mock_add_to_engine;
> + engine->base.remove_active_request = mock_remove_from_engine;
>
> engine->base.reset.prepare = mock_reset_prepare;
> engine->base.reset.rewind = mock_reset_rewind;
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 9f28899ff17f..f8a6077fa3f9 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -1147,6 +1147,33 @@ static int guc_context_alloc(struct intel_context *ce)
> return lrc_alloc(ce, ce->engine);
> }
>
> +static void add_to_context(struct i915_request *rq)
> +{
> + struct intel_context *ce = rq->context;
> +
> + spin_lock(&ce->guc_active.lock);
> + list_move_tail(&rq->sched.link, &ce->guc_active.requests);
> + spin_unlock(&ce->guc_active.lock);
> +}
> +
> +static void remove_from_context(struct i915_request *rq)
> +{
> + struct intel_context *ce = rq->context;
> +
> + spin_lock_irq(&ce->guc_active.lock);
> +
> + list_del_init(&rq->sched.link);
> + clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
> +
> + /* Prevent further __await_execution() registering a cb, then flush */
> + set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
> +
> + spin_unlock_irq(&ce->guc_active.lock);
> +
> + atomic_dec(&ce->guc_id_ref);
> + i915_request_notify_execute_cb_imm(rq);
> +}
> +
> static const struct intel_context_ops guc_context_ops = {
> .alloc = guc_context_alloc,
>
> @@ -1567,6 +1594,8 @@ static void guc_default_vfuncs(struct intel_engine_cs *engine)
> engine->cops = &guc_context_ops;
> engine->request_alloc = guc_request_alloc;
> engine->bump_serial = guc_bump_serial;
> + engine->add_active_request = add_to_context;
> + engine->remove_active_request = remove_from_context;
>
> engine->sched_engine->schedule = i915_schedule;
>
> @@ -1931,6 +1960,10 @@ guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
> "v%dx%d", ve->base.class, count);
> ve->base.context_size = sibling->context_size;
>
> + ve->base.add_active_request =
> + sibling->add_active_request;
> + ve->base.remove_active_request =
> + sibling->remove_active_request;
> ve->base.emit_bb_start = sibling->emit_bb_start;
> ve->base.emit_flush = sibling->emit_flush;
> ve->base.emit_init_breadcrumb =
> diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
> index b3c792d55321..4eba848b20e3 100644
> --- a/drivers/gpu/drm/i915/i915_request.c
> +++ b/drivers/gpu/drm/i915/i915_request.c
> @@ -182,7 +182,7 @@ static bool irq_work_imm(struct irq_work *wrk)
> return false;
> }
>
> -static void __notify_execute_cb_imm(struct i915_request *rq)
> +void i915_request_notify_execute_cb_imm(struct i915_request *rq)
> {
> __notify_execute_cb(rq, irq_work_imm);
> }
> @@ -256,37 +256,6 @@ i915_request_active_engine(struct i915_request *rq,
> return ret;
> }
>
> -
> -static void remove_from_engine(struct i915_request *rq)
> -{
> - struct intel_engine_cs *engine, *locked;
> -
> - /*
> - * Virtual engines complicate acquiring the engine timeline lock,
> - * as their rq->engine pointer is not stable until under that
> - * engine lock. The simple ploy we use is to take the lock then
> - * check that the rq still belongs to the newly locked engine.
> - */
> - locked = READ_ONCE(rq->engine);
> - spin_lock_irq(&locked->sched_engine->lock);
> - while (unlikely(locked != (engine = READ_ONCE(rq->engine)))) {
> - spin_unlock(&locked->sched_engine->lock);
> - spin_lock(&engine->sched_engine->lock);
> - locked = engine;
> - }
> - list_del_init(&rq->sched.link);
> -
> - clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
> - clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags);
> -
> - /* Prevent further __await_execution() registering a cb, then flush */
> - set_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
> -
> - spin_unlock_irq(&locked->sched_engine->lock);
> -
> - __notify_execute_cb_imm(rq);
> -}
> -
> static void __rq_init_watchdog(struct i915_request *rq)
> {
> rq->watchdog.timer.function = NULL;
> @@ -383,9 +352,7 @@ bool i915_request_retire(struct i915_request *rq)
> * after removing the breadcrumb and signaling it, so that we do not
> * inadvertently attach the breadcrumb to a completed request.
> */
> - if (!list_empty(&rq->sched.link))
> - remove_from_engine(rq);
> - atomic_dec(&rq->context->guc_id_ref);
> + rq->engine->remove_active_request(rq);
> GEM_BUG_ON(!llist_empty(&rq->execute_cb));
>
> __list_del_entry(&rq->link); /* poison neither prev/next (RCU walks) */
> @@ -516,7 +483,7 @@ __await_execution(struct i915_request *rq,
> if (llist_add(&cb->work.node.llist, &signal->execute_cb)) {
> if (i915_request_is_active(signal) ||
> __request_in_flight(signal))
> - __notify_execute_cb_imm(signal);
> + i915_request_notify_execute_cb_imm(signal);
> }
>
> return 0;
> @@ -653,7 +620,7 @@ bool __i915_request_submit(struct i915_request *request)
> result = true;
>
> GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));
> - list_move_tail(&request->sched.link, &engine->sched_engine->requests);
> + engine->add_active_request(request);
> active:
> clear_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags);
> set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);
> diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
> index 717e5b292046..128030f43bbf 100644
> --- a/drivers/gpu/drm/i915/i915_request.h
> +++ b/drivers/gpu/drm/i915/i915_request.h
> @@ -647,4 +647,6 @@ bool
> i915_request_active_engine(struct i915_request *rq,
> struct intel_engine_cs **active);
>
> +void i915_request_notify_execute_cb_imm(struct i915_request *rq);
> +
> #endif /* I915_REQUEST_H */