Re: [PATCH 27/47] drm/i915: Track 'serial' counts for virtual engines

On 6/24/2021 00:04, Matthew Brost wrote:

From: John Harrison John.C.Harrison@Intel.com

The serial number tracking of engines happens at the backend of request submission and was expecting to only be given physical engines. However, in GuC submission mode, the decomposition of virtual to physical engines does not happen in i915. Instead, requests are submitted to their virtual engine mask all the way through to the hardware (i.e. to GuC). This would mean that the heart beat code thinks the physical engines are idle due to the serial number not incrementing.

This patch updates the tracking to decompose virtual engines into their physical constituents and tracks the request against each. This is not entirely accurate as the GuC will only be issuing the request to one physical engine. However, it is the best that i915 can do given that it has no knowledge of the GuC's scheduling decisions.

Signed-off-by: John Harrison John.C.Harrison@Intel.com Signed-off-by: Matthew Brost matthew.brost@intel.com

Need to pull in the updated subject line and commit description from Tvrtko in the RFC patch set review.

John.

---

drivers/gpu/drm/i915/gt/intel_engine_types.h | 2 ++ .../gpu/drm/i915/gt/intel_execlists_submission.c | 6 ++++++ drivers/gpu/drm/i915/gt/intel_ring_submission.c | 6 ++++++ drivers/gpu/drm/i915/gt/mock_engine.c | 6 ++++++ .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 16 ++++++++++++++++ drivers/gpu/drm/i915/i915_request.c | 4 +++- 6 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index 5b91068ab277..1dc59e6c9a92 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -388,6 +388,8 @@ struct intel_engine_cs { void (*park)(struct intel_engine_cs *engine); void (*unpark)(struct intel_engine_cs *engine);

• void (*bump_serial)(struct intel_engine_cs *engine);

• void (*set_default_submission)(struct intel_engine_cs *engine);

  const struct intel_context_ops *cops;

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c index bd4ced794ff9..9cfb8800a0e6 100644 --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c @@ -3203,6 +3203,11 @@ static void execlists_release(struct intel_engine_cs *engine) lrc_fini_wa_ctx(engine); }

+static void execlist_bump_serial(struct intel_engine_cs *engine) +{

• engine->serial++;

+}

• static void logical_ring_default_vfuncs(struct intel_engine_cs *engine) {

@@ -3212,6 +3217,7 @@ 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->reset.prepare = execlists_reset_prepare; engine->reset.rewind = execlists_reset_rewind;

diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c index 5d42a12ef3d6..e1506b280df1 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c @@ -1044,6 +1044,11 @@ static void setup_irq(struct intel_engine_cs *engine) } }

+static void ring_bump_serial(struct intel_engine_cs *engine) +{

• engine->serial++;

+}

• static void setup_common(struct intel_engine_cs *engine) { struct drm_i915_private *i915 = engine->i915;

@@ -1063,6 +1068,7 @@ static void setup_common(struct intel_engine_cs *engine)

engine->cops = &ring_context_ops; engine->request_alloc = ring_request_alloc;

• engine->bump_serial = ring_bump_serial;

  /*

  • Using a global execution timeline; the previous final breadcrumb is

diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c index 68970398e4ef..9203c766db80 100644 --- a/drivers/gpu/drm/i915/gt/mock_engine.c +++ b/drivers/gpu/drm/i915/gt/mock_engine.c @@ -292,6 +292,11 @@ static void mock_engine_release(struct intel_engine_cs *engine) intel_engine_fini_retire(engine); }

+static void mock_bump_serial(struct intel_engine_cs *engine) +{

• engine->serial++;

+}

• struct intel_engine_cs *mock_engine(struct drm_i915_private *i915, const char *name, int id)

@@ -318,6 +323,7 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,

engine->base.cops = &mock_context_ops; engine->base.request_alloc = mock_request_alloc;

• engine->base.bump_serial = mock_bump_serial; engine->base.emit_flush = mock_emit_flush; engine->base.emit_fini_breadcrumb = mock_emit_breadcrumb; engine->base.submit_request = mock_submit_request;

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 ccbcf024b31b..d1badd7137b7 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -1496,6 +1496,20 @@ static void guc_release(struct intel_engine_cs *engine) lrc_fini_wa_ctx(engine); }

+static void guc_bump_serial(struct intel_engine_cs *engine) +{

• engine->serial++;

+}

+static void virtual_guc_bump_serial(struct intel_engine_cs *engine) +{

• struct intel_engine_cs *e;
• intel_engine_mask_t tmp, mask = engine->mask;
• for_each_engine_masked(e, engine->gt, mask, tmp)

• e->serial++;
  

+}

• static void guc_default_vfuncs(struct intel_engine_cs *engine) { /* Default vfuncs which can be overridden by each engine. */

@@ -1504,6 +1518,7 @@ 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->sched_engine->schedule = i915_schedule;

@@ -1836,6 +1851,7 @@ guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)

ve->base.cops = &virtual_guc_context_ops; ve->base.request_alloc = guc_request_alloc;

• ve->base.bump_serial = virtual_guc_bump_serial;

  ve->base.submit_request = guc_submit_request;

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 7f7aa096e873..de9deb95b8b1 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -692,7 +692,9 @@ bool __i915_request_submit(struct i915_request *request) request->ring->vaddr + request->postfix);

trace_i915_request_execute(request);

• engine->serial++;

• if (engine->bump_serial)

• engine->bump_serial(engine);
  

• result = true;

  GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));