[Intel-gfx] [PATCH 36/42] drm/i915: Move the global sync optimisation to the timeline

Chris Wilson chris at chris-wilson.co.uk
Fri Oct 7 09:46:29 UTC 2016


Currently we try to reduce the number of synchronisations (now the
number of requests we need to wait upon) by noting that if we have
earlier waited upon a request, all subsequent requests in the timeline
will be after the wait. This only applies to requests in this timeline,
as other timelines will not be ordered by that waiter.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c      |  9 ------
 drivers/gpu/drm/i915/i915_drv.h          |  1 -
 drivers/gpu/drm/i915/i915_gem_request.c  | 30 ++++++++++++--------
 drivers/gpu/drm/i915/i915_gem_timeline.h |  1 +
 drivers/gpu/drm/i915/i915_gpu_error.c    | 48 +++++++++++++++++++-------------
 drivers/gpu/drm/i915/intel_engine_cs.c   |  2 --
 drivers/gpu/drm/i915/intel_ringbuffer.c  |  3 --
 drivers/gpu/drm/i915/intel_ringbuffer.h  | 23 ---------------
 8 files changed, 48 insertions(+), 69 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 77491eb3340f..8640d2d805bd 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -3257,15 +3257,6 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
 		seq_putc(m, '\n');
 	}
 
-	seq_puts(m, "\nSync seqno:\n");
-	for_each_engine(engine, dev_priv) {
-		for (j = 0; j < num_rings; j++)
-			seq_printf(m, "  0x%08x ",
-				   engine->semaphore.sync_seqno[j]);
-		seq_putc(m, '\n');
-	}
-	seq_putc(m, '\n');
-
 	intel_runtime_pm_put(dev_priv);
 	mutex_unlock(&dev->struct_mutex);
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 78b54fb4b56b..1620703f4a64 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -798,7 +798,6 @@ struct drm_i915_error_state {
 		u32 cpu_ring_tail;
 
 		u32 last_seqno;
-		u32 semaphore_seqno[I915_NUM_ENGINES - 1];
 
 		/* Register state */
 		u32 start;
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 0b8a26803036..e0f627a94fde 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -238,34 +238,41 @@ static int i915_gem_check_wedge(struct drm_i915_private *dev_priv)
 	return 0;
 }
 
-static int i915_gem_init_global_seqno(struct drm_i915_private *dev_priv,
-				      u32 seqno)
+static int i915_gem_init_global_seqno(struct drm_i915_private *i915, u32 seqno)
 {
-	struct i915_gem_timeline *timeline = &dev_priv->gt.global_timeline;
+	struct i915_gem_timeline *timeline = &i915->gt.global_timeline;
 	struct intel_engine_cs *engine;
 	int ret;
 
 	/* Carefully retire all requests without writing to the rings */
-	ret = i915_gem_wait_for_idle(dev_priv,
+	ret = i915_gem_wait_for_idle(i915,
 				     I915_WAIT_INTERRUPTIBLE |
 				     I915_WAIT_LOCKED);
 	if (ret)
 		return ret;
 
-	i915_gem_retire_requests(dev_priv);
+	i915_gem_retire_requests(i915);
 
 	/* If the seqno wraps around, we need to clear the breadcrumb rbtree */
 	if (!i915_seqno_passed(seqno, timeline->next_seqno)) {
-		while (intel_kick_waiters(dev_priv) ||
-		       intel_kick_signalers(dev_priv))
+		while (intel_kick_waiters(i915) || intel_kick_signalers(i915))
 			yield();
 		yield();
 	}
 
 	/* Finally reset hw state */
-	for_each_engine(engine, dev_priv)
+	for_each_engine(engine, i915)
 		intel_engine_init_global_seqno(engine, seqno);
 
+	list_for_each_entry(timeline, &i915->gt.timelines, link) {
+		for_each_engine(engine, i915) {
+			struct intel_timeline *tl =
+				&timeline->engine[engine->id];
+
+			memset(tl->sync_seqno, 0, sizeof(tl->sync_seqno));
+		}
+	}
+
 	return 0;
 }
 
@@ -461,7 +468,7 @@ static int
 i915_gem_request_await_request(struct drm_i915_gem_request *to,
 			       struct drm_i915_gem_request *from)
 {
-	int idx, ret;
+	int ret;
 
 	GEM_BUG_ON(to == from);
 
@@ -482,8 +489,7 @@ i915_gem_request_await_request(struct drm_i915_gem_request *to,
 		return ret < 0 ? ret : 0;
 	}
 
-	idx = intel_engine_sync_index(from->engine, to->engine);
-	if (from->global_seqno <= from->engine->semaphore.sync_seqno[idx])
+	if (from->global_seqno <= to->timeline->sync_seqno[from->engine->id])
 		return 0;
 
 	trace_i915_gem_ring_sync_to(to, from);
@@ -501,7 +507,7 @@ i915_gem_request_await_request(struct drm_i915_gem_request *to,
 			return ret;
 	}
 
-	from->engine->semaphore.sync_seqno[idx] = from->global_seqno;
+	to->timeline->sync_seqno[from->engine->id] = from->global_seqno;
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_gem_timeline.h b/drivers/gpu/drm/i915/i915_gem_timeline.h
index bfdf0331cc50..767b23914ec5 100644
--- a/drivers/gpu/drm/i915/i915_gem_timeline.h
+++ b/drivers/gpu/drm/i915/i915_gem_timeline.h
@@ -48,6 +48,7 @@ struct intel_timeline {
 	 * struct_mutex.
 	 */
 	struct i915_gem_active last_request;
+	u32 sync_seqno[I915_NUM_ENGINES];
 
 	struct i915_gem_timeline *common;
 };
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index b6bf6fafd849..6bbe84e732b3 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -403,17 +403,13 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
 	if (INTEL_GEN(m->i915) >= 6) {
 		err_printf(m, "  RC PSMI: 0x%08x\n", ee->rc_psmi);
 		err_printf(m, "  FAULT_REG: 0x%08x\n", ee->fault_reg);
-		err_printf(m, "  SYNC_0: 0x%08x [last synced 0x%08x]\n",
-			   ee->semaphore_mboxes[0],
-			   ee->semaphore_seqno[0]);
-		err_printf(m, "  SYNC_1: 0x%08x [last synced 0x%08x]\n",
-			   ee->semaphore_mboxes[1],
-			   ee->semaphore_seqno[1]);
-		if (HAS_VEBOX(m->i915)) {
-			err_printf(m, "  SYNC_2: 0x%08x [last synced 0x%08x]\n",
-				   ee->semaphore_mboxes[2],
-				   ee->semaphore_seqno[2]);
-		}
+		err_printf(m, "  SYNC_0: 0x%08x\n",
+			   ee->semaphore_mboxes[0]);
+		err_printf(m, "  SYNC_1: 0x%08x\n",
+			   ee->semaphore_mboxes[1]);
+		if (HAS_VEBOX(m->i915))
+			err_printf(m, "  SYNC_2: 0x%08x\n",
+				   ee->semaphore_mboxes[2]);
 	}
 	if (USES_PPGTT(m->i915)) {
 		err_printf(m, "  GFX_MODE: 0x%08x\n", ee->vm_info.gfx_mode);
@@ -957,6 +953,26 @@ static void i915_gem_record_fences(struct drm_i915_private *dev_priv,
 	}
 }
 
+static inline u32
+gen8_engine_sync_index(struct intel_engine_cs *engine,
+		       struct intel_engine_cs *other)
+{
+	int idx;
+
+	/*
+	 * rcs -> 0 = vcs, 1 = bcs, 2 = vecs, 3 = vcs2;
+	 * vcs -> 0 = bcs, 1 = vecs, 2 = vcs2, 3 = rcs;
+	 * bcs -> 0 = vecs, 1 = vcs2. 2 = rcs, 3 = vcs;
+	 * vecs -> 0 = vcs2, 1 = rcs, 2 = vcs, 3 = bcs;
+	 * vcs2 -> 0 = rcs, 1 = vcs, 2 = bcs, 3 = vecs;
+	 */
+
+	idx = (other - engine) - 1;
+	if (idx < 0)
+		idx += I915_NUM_ENGINES;
+
+	return idx;
+}
 
 static void gen8_record_semaphore_state(struct drm_i915_error_state *error,
 					struct intel_engine_cs *engine,
@@ -980,10 +996,9 @@ static void gen8_record_semaphore_state(struct drm_i915_error_state *error,
 		signal_offset =
 			(GEN8_SIGNAL_OFFSET(engine, id) & (PAGE_SIZE - 1)) / 4;
 		tmp = error->semaphore->pages[0];
-		idx = intel_engine_sync_index(engine, to);
+		idx = gen8_engine_sync_index(engine, to);
 
 		ee->semaphore_mboxes[idx] = tmp[signal_offset];
-		ee->semaphore_seqno[idx] = engine->semaphore.sync_seqno[idx];
 	}
 }
 
@@ -994,14 +1009,9 @@ static void gen6_record_semaphore_state(struct intel_engine_cs *engine,
 
 	ee->semaphore_mboxes[0] = I915_READ(RING_SYNC_0(engine->mmio_base));
 	ee->semaphore_mboxes[1] = I915_READ(RING_SYNC_1(engine->mmio_base));
-	ee->semaphore_seqno[0] = engine->semaphore.sync_seqno[0];
-	ee->semaphore_seqno[1] = engine->semaphore.sync_seqno[1];
-
-	if (HAS_VEBOX(dev_priv)) {
+	if (HAS_VEBOX(dev_priv))
 		ee->semaphore_mboxes[2] =
 			I915_READ(RING_SYNC_2(engine->mmio_base));
-		ee->semaphore_seqno[2] = engine->semaphore.sync_seqno[2];
-	}
 }
 
 static void error_record_engine_waiters(struct intel_engine_cs *engine,
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 276f3f38ab41..755f1a8b76d8 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -191,8 +191,6 @@ void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
 				       I915_NUM_ENGINES * gen8_semaphore_seqno_size);
 		kunmap(page);
 	}
-	memset(engine->semaphore.sync_seqno, 0,
-	       sizeof(engine->semaphore.sync_seqno));
 
 	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
 	if (engine->irq_seqno_barrier)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 921614b43d79..3abfbe3cfed9 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2004,9 +2004,6 @@ static int intel_init_ring_buffer(struct intel_engine_cs *engine)
 
 	intel_engine_setup_common(engine);
 
-	memset(engine->semaphore.sync_seqno, 0,
-	       sizeof(engine->semaphore.sync_seqno));
-
 	ret = intel_engine_init_common(engine);
 	if (ret)
 		goto error;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 871bddd85e4a..652e37c9e0c9 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -314,8 +314,6 @@ struct intel_engine_cs {
 	 *  ie. transpose of f(x, y)
 	 */
 	struct {
-		u32	sync_seqno[I915_NUM_ENGINES-1];
-
 		union {
 #define GEN6_SEMAPHORE_LAST	VECS_HW
 #define GEN6_NUM_SEMAPHORES	(GEN6_SEMAPHORE_LAST + 1)
@@ -391,27 +389,6 @@ intel_engine_flag(const struct intel_engine_cs *engine)
 	return 1 << engine->id;
 }
 
-static inline u32
-intel_engine_sync_index(struct intel_engine_cs *engine,
-			struct intel_engine_cs *other)
-{
-	int idx;
-
-	/*
-	 * rcs -> 0 = vcs, 1 = bcs, 2 = vecs, 3 = vcs2;
-	 * vcs -> 0 = bcs, 1 = vecs, 2 = vcs2, 3 = rcs;
-	 * bcs -> 0 = vecs, 1 = vcs2. 2 = rcs, 3 = vcs;
-	 * vecs -> 0 = vcs2, 1 = rcs, 2 = vcs, 3 = bcs;
-	 * vcs2 -> 0 = rcs, 1 = vcs, 2 = bcs, 3 = vecs;
-	 */
-
-	idx = (other - engine) - 1;
-	if (idx < 0)
-		idx += I915_NUM_ENGINES;
-
-	return idx;
-}
-
 static inline void
 intel_flush_status_page(struct intel_engine_cs *engine, int reg)
 {
-- 
2.9.3



More information about the Intel-gfx mailing list