Mesa (master): i965/gen6-7/sol: Keep independent counters for the current and previous begin/end block.
Francisco Jerez
currojerez at kemper.freedesktop.org
Wed Jan 17 04:52:05 UTC 2018
Module: Mesa
Branch: master
Commit: f476b3f6e7b9f61c5bd93cf463005fd88aacaeba
URL: http://cgit.freedesktop.org/mesa/mesa/commit/?id=f476b3f6e7b9f61c5bd93cf463005fd88aacaeba
Author: Francisco Jerez <currojerez at riseup.net>
Date: Thu Nov 16 14:27:41 2017 -0800
i965/gen6-7/sol: Keep independent counters for the current and previous begin/end block.
This allows us to aggregate the primitive counts of a completed
transform feedback begin/end block lazily, which in the most typical
case (where glDrawTransformFeedback is not used) will allow us to
avoid aggregating the primitive counters on the CPU altogether,
preventing a stall on previous rendering during
glBeginTransformFeedback(), which dramatically improves performance of
applications that rely heavily on transform feedback.
Improves performance of SynMark2 OglGSCloth by 65.52% ±0.25% (data
gathered on VLV).
Tested-By: Eero Tamminen <eero.t.tamminen at intel.com>
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
---
src/mesa/drivers/dri/i965/brw_context.h | 9 ++++---
src/mesa/drivers/dri/i965/gen6_sol.c | 39 +++++++++++++++++-------------
src/mesa/drivers/dri/i965/gen7_sol_state.c | 15 ++++++------
3 files changed, 36 insertions(+), 27 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_context.h b/src/mesa/drivers/dri/i965/brw_context.h
index 950ede05fc..8d8ab71093 100644
--- a/src/mesa/drivers/dri/i965/brw_context.h
+++ b/src/mesa/drivers/dri/i965/brw_context.h
@@ -579,6 +579,12 @@ struct brw_transform_feedback_object {
struct brw_transform_feedback_counter counter;
/**
+ * Count of primitives generated during the previous transform feedback
+ * operation. Used to implement DrawTransformFeedback().
+ */
+ struct brw_transform_feedback_counter previous_counter;
+
+ /**
* Number of vertices written between last Begin/EndTransformFeedback().
*
* Used to implement DrawTransformFeedback().
@@ -1519,9 +1525,6 @@ brw_resume_transform_feedback(struct gl_context *ctx,
void
brw_save_primitives_written_counters(struct brw_context *brw,
struct brw_transform_feedback_object *obj);
-void
-brw_compute_xfb_vertices_written(struct brw_context *brw,
- struct brw_transform_feedback_object *obj);
GLsizei
brw_get_transform_feedback_vertex_count(struct gl_context *ctx,
struct gl_transform_feedback_object *obj,
diff --git a/src/mesa/drivers/dri/i965/gen6_sol.c b/src/mesa/drivers/dri/i965/gen6_sol.c
index a909339e16..b1baf01bcd 100644
--- a/src/mesa/drivers/dri/i965/gen6_sol.c
+++ b/src/mesa/drivers/dri/i965/gen6_sol.c
@@ -289,6 +289,8 @@ brw_save_primitives_written_counters(struct brw_context *brw,
/* Check if there's enough space for a new pair of four values. */
if ((obj->counter.bo_end + 2) * streams * sizeof(uint64_t) >= 4096) {
aggregate_transform_feedback_counter(brw, obj->prim_count_bo,
+ &obj->previous_counter);
+ aggregate_transform_feedback_counter(brw, obj->prim_count_bo,
&obj->counter);
}
@@ -316,6 +318,7 @@ brw_save_primitives_written_counters(struct brw_context *brw,
static void
compute_vertices_written_so_far(struct brw_context *brw,
struct brw_transform_feedback_object *obj,
+ struct brw_transform_feedback_counter *counter,
uint64_t *vertices_written)
{
const struct gl_context *ctx = &brw->ctx;
@@ -336,25 +339,26 @@ compute_vertices_written_so_far(struct brw_context *brw,
}
/* Get the number of primitives generated. */
- aggregate_transform_feedback_counter(brw, obj->prim_count_bo, &obj->counter);
+ aggregate_transform_feedback_counter(brw, obj->prim_count_bo, counter);
for (int i = 0; i < ctx->Const.MaxVertexStreams; i++) {
- vertices_written[i] = vertices_per_prim * obj->counter.accum[i];
+ vertices_written[i] = vertices_per_prim * counter->accum[i];
}
}
/**
- * Compute the number of vertices written by this transform feedback operation.
+ * Compute the number of vertices written by the last transform feedback
+ * begin/end block.
*/
-void
-brw_compute_xfb_vertices_written(struct brw_context *brw,
- struct brw_transform_feedback_object *obj)
+static void
+compute_xfb_vertices_written(struct brw_context *brw,
+ struct brw_transform_feedback_object *obj)
{
if (obj->vertices_written_valid || !obj->base.EndedAnytime)
return;
- compute_vertices_written_so_far(brw, obj, obj->vertices_written);
-
+ compute_vertices_written_so_far(brw, obj, &obj->previous_counter,
+ obj->vertices_written);
obj->vertices_written_valid = true;
}
@@ -376,7 +380,7 @@ brw_get_transform_feedback_vertex_count(struct gl_context *ctx,
assert(obj->EndedAnytime);
assert(stream < ctx->Const.MaxVertexStreams);
- brw_compute_xfb_vertices_written(brw, brw_obj);
+ compute_xfb_vertices_written(brw, brw_obj);
return brw_obj->vertices_written[stream];
}
@@ -431,13 +435,6 @@ brw_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
ADVANCE_BATCH();
}
- /* We're about to lose the information needed to compute the number of
- * vertices written during the last Begin/EndTransformFeedback section,
- * so we can't delay it any further.
- */
- brw_compute_xfb_vertices_written(brw, brw_obj);
- brw_reset_transform_feedback_counter(&brw_obj->counter);
-
/* Store the starting value of the SO_NUM_PRIMS_WRITTEN counters. */
brw_save_primitives_written_counters(brw, brw_obj);
@@ -456,6 +453,14 @@ brw_end_transform_feedback(struct gl_context *ctx,
if (!obj->Paused)
brw_save_primitives_written_counters(brw, brw_obj);
+ /* We've reached the end of a transform feedback begin/end block. This
+ * means that future DrawTransformFeedback() calls will need to pick up the
+ * results of the current counter, and that it's time to roll back the
+ * current primitive counter to zero.
+ */
+ brw_obj->previous_counter = brw_obj->counter;
+ brw_reset_transform_feedback_counter(&brw_obj->counter);
+
/* EndTransformFeedback() means that we need to update the number of
* vertices written. Since it's only necessary if DrawTransformFeedback()
* is called and it means mapping a buffer object, we delay computing it
@@ -490,7 +495,7 @@ brw_resume_transform_feedback(struct gl_context *ctx,
/* Reload SVBI 0 with the count of vertices written so far. */
uint64_t svbi;
- compute_vertices_written_so_far(brw, brw_obj, &svbi);
+ compute_vertices_written_so_far(brw, brw_obj, &brw_obj->counter, &svbi);
BEGIN_BATCH(4);
OUT_BATCH(_3DSTATE_GS_SVB_INDEX << 16 | (4 - 2));
diff --git a/src/mesa/drivers/dri/i965/gen7_sol_state.c b/src/mesa/drivers/dri/i965/gen7_sol_state.c
index f097e2250b..3801c73f65 100644
--- a/src/mesa/drivers/dri/i965/gen7_sol_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_sol_state.c
@@ -45,13 +45,6 @@ gen7_begin_transform_feedback(struct gl_context *ctx, GLenum mode,
assert(brw->screen->devinfo.gen == 7);
- /* We're about to lose the information needed to compute the number of
- * vertices written during the last Begin/EndTransformFeedback section,
- * so we can't delay it any further.
- */
- brw_compute_xfb_vertices_written(brw, brw_obj);
- brw_reset_transform_feedback_counter(&brw_obj->counter);
-
/* Store the starting value of the SO_NUM_PRIMS_WRITTEN counters. */
brw_save_primitives_written_counters(brw, brw_obj);
@@ -86,6 +79,14 @@ gen7_end_transform_feedback(struct gl_context *ctx,
if (!obj->Paused)
brw_save_primitives_written_counters(brw, brw_obj);
+ /* We've reached the end of a transform feedback begin/end block. This
+ * means that future DrawTransformFeedback() calls will need to pick up the
+ * results of the current counter, and that it's time to roll back the
+ * current primitive counter to zero.
+ */
+ brw_obj->previous_counter = brw_obj->counter;
+ brw_reset_transform_feedback_counter(&brw_obj->counter);
+
/* EndTransformFeedback() means that we need to update the number of
* vertices written. Since it's only necessary if DrawTransformFeedback()
* is called and it means mapping a buffer object, we delay computing it
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