Mesa (10.1): r600g,radeonsi: Consolidate logic for short-circuiting flushes

[Ian Romanick]

Module: Mesa
Branch: 10.1
Commit: 20eb46699905e4ed9a4886fdb83caf72a344fb71
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=20eb46699905e4ed9a4886fdb83caf72a344fb71

Author: Michel Dänzer <michel.daenzer at amd.com>
Date:   Thu Feb 13 11:51:09 2014 +0900

r600g,radeonsi: Consolidate logic for short-circuiting flushes

Fixes radeonsi emitting command streams to the kernel even when there
have been no draw calls before a flush, potentially powering up the GPU
needlessly.

Incidentally, this also cuts the runtime of piglit gpu.py in about half
on my Kaveri system, probably because an X11 client going away no longer
always results in a command stream being submitted to the kernel via
glamor.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=65761
Cc: "10.1" mesa-stable at lists.freedesktop.org
Reviewed-by: Marek Olšák <marek.olsak at amd.com>
(cherry picked from commit cf0172d46ab940a691da6516057c81f28961482f)

---

 src/gallium/drivers/r600/r600_hw_context.c      |    2 +-
 src/gallium/drivers/r600/r600_pipe.c            |    4 ++--
 src/gallium/drivers/r600/r600_pipe.h            |    1 -
 src/gallium/drivers/radeon/r600_buffer_common.c |    2 +-
 src/gallium/drivers/radeon/r600_pipe_common.h   |    1 +
 src/gallium/drivers/radeonsi/si_hw_context.c    |    4 +++-
 6 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_hw_context.c b/src/gallium/drivers/r600/r600_hw_context.c
index fc81e95..358282a 100644
--- a/src/gallium/drivers/r600/r600_hw_context.c
+++ b/src/gallium/drivers/r600/r600_hw_context.c
@@ -352,7 +352,7 @@ void r600_begin_new_cs(struct r600_context *ctx)
 	ctx->last_primitive_type = -1;
 	ctx->last_start_instance = -1;
 
-	ctx->initial_gfx_cs_size = ctx->b.rings.gfx.cs->cdw;
+	ctx->b.initial_gfx_cs_size = ctx->b.rings.gfx.cs->cdw;
 }
 
 /* The max number of bytes to copy per packet. */
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index 66996bd..4ca6a22 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -73,7 +73,7 @@ static void r600_flush(struct pipe_context *ctx, unsigned flags)
 	unsigned render_cond_mode = 0;
 	boolean render_cond_cond = FALSE;
 
-	if (rctx->b.rings.gfx.cs->cdw == rctx->initial_gfx_cs_size)
+	if (rctx->b.rings.gfx.cs->cdw == rctx->b.initial_gfx_cs_size)
 		return;
 
 	rctx->b.rings.gfx.flushing = true;
@@ -94,7 +94,7 @@ static void r600_flush(struct pipe_context *ctx, unsigned flags)
 		ctx->render_condition(ctx, render_cond, render_cond_cond, render_cond_mode);
 	}
 
-	rctx->initial_gfx_cs_size = rctx->b.rings.gfx.cs->cdw;
+	rctx->b.initial_gfx_cs_size = rctx->b.rings.gfx.cs->cdw;
 }
 
 static void r600_flush_from_st(struct pipe_context *ctx,
diff --git a/src/gallium/drivers/r600/r600_pipe.h b/src/gallium/drivers/r600/r600_pipe.h
index 9f27a17..0cc91dd 100644
--- a/src/gallium/drivers/r600/r600_pipe.h
+++ b/src/gallium/drivers/r600/r600_pipe.h
@@ -375,7 +375,6 @@ struct r600_context {
 	struct r600_screen		*screen;
 	struct blitter_context		*blitter;
 	struct u_suballocator		*allocator_fetch_shader;
-	unsigned			initial_gfx_cs_size;
 
 	/* Hardware info. */
 	boolean				has_vertex_cache;
diff --git a/src/gallium/drivers/radeon/r600_buffer_common.c b/src/gallium/drivers/radeon/r600_buffer_common.c
index d29671e..15eec55 100644
--- a/src/gallium/drivers/radeon/r600_buffer_common.c
+++ b/src/gallium/drivers/radeon/r600_buffer_common.c
@@ -59,7 +59,7 @@ void *r600_buffer_map_sync_with_rings(struct r600_common_context *ctx,
 		rusage = RADEON_USAGE_WRITE;
 	}
 
-	if (ctx->rings.gfx.cs->cdw &&
+	if (ctx->rings.gfx.cs->cdw != ctx->initial_gfx_cs_size &&
 	    ctx->ws->cs_is_buffer_referenced(ctx->rings.gfx.cs,
 					     resource->cs_buf, rusage)) {
 		if (usage & PIPE_TRANSFER_DONTBLOCK) {
diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h b/src/gallium/drivers/radeon/r600_pipe_common.h
index aa1f3ed..3c22c0f 100644
--- a/src/gallium/drivers/radeon/r600_pipe_common.h
+++ b/src/gallium/drivers/radeon/r600_pipe_common.h
@@ -241,6 +241,7 @@ struct r600_common_context {
 	enum radeon_family		family;
 	enum chip_class			chip_class;
 	struct r600_rings		rings;
+	unsigned			initial_gfx_cs_size;
 
 	struct u_upload_mgr		*uploader;
 	struct u_suballocator		*allocator_so_filled_size;
diff --git a/src/gallium/drivers/radeonsi/si_hw_context.c b/src/gallium/drivers/radeonsi/si_hw_context.c
index 7e40255..3437f59 100644
--- a/src/gallium/drivers/radeonsi/si_hw_context.c
+++ b/src/gallium/drivers/radeonsi/si_hw_context.c
@@ -81,7 +81,7 @@ void si_context_flush(struct si_context *ctx, unsigned flags)
 {
 	struct radeon_winsys_cs *cs = ctx->b.rings.gfx.cs;
 
-	if (!cs->cdw)
+	if (cs->cdw == ctx->b.initial_gfx_cs_size)
 		return;
 
 	/* suspend queries */
@@ -177,6 +177,8 @@ void si_begin_new_cs(struct si_context *ctx)
 	}
 
 	si_all_descriptors_begin_new_cs(ctx);
+
+	ctx->b.initial_gfx_cs_size = ctx->b.rings.gfx.cs->cdw;
 }
 
 #if SI_TRACE_CS