On 28.05.2018 12:21, Bas Nieuwenhuizen wrote:
On Mon, May 28, 2018 at 12:19 PM, Nicolai Hähnle <[email protected]> wrote:
On 27.05.2018 18:57, Bas Nieuwenhuizen wrote:

This improves dota2 performance for me by 11% when I force the
GPU DPM level to low (otherwise dota2 is CPU limited for 4k on my
threadripper), which should be a large part of the radv-amdvlk gap.
(For me with that was radv 60.3 -> 66.6, while AMDVLK does about 68
fps)

It looks like dota2 rendered the GUI with a bunch of draws with
a SetScissors before almost each draw, causing a lot of pipeline
stalls.

I'm not really happy with the duplication of code, but overriding
radeon_set_context_reg would also be messy since we have the
pre-recorded pipelines and a bunch of si_cmd_buffer code, as well
as some memory->context reg loads for which things would be more
complicated.
---
   src/amd/vulkan/radv_cmd_buffer.c | 56 +++++++++++++++++++++++++++-----
   1 file changed, 47 insertions(+), 9 deletions(-)

diff --git a/src/amd/vulkan/radv_cmd_buffer.c
b/src/amd/vulkan/radv_cmd_buffer.c
index 5ab577b4c59..08be50995c1 100644
--- a/src/amd/vulkan/radv_cmd_buffer.c
+++ b/src/amd/vulkan/radv_cmd_buffer.c
@@ -869,14 +869,6 @@ radv_emit_scissor(struct radv_cmd_buffer *cmd_buffer)
   {
         uint32_t count = cmd_buffer->state.dynamic.scissor.count;
   -     /* Vega10/Raven scissor bug workaround. This must be done before
VPORT
-        * scissor registers are changed. There is also a more efficient
but
-        * more involved alternative workaround.
-        */
-       if (cmd_buffer->device->physical_device->has_scissor_bug) {
-               cmd_buffer->state.flush_bits |=
RADV_CMD_FLAG_PS_PARTIAL_FLUSH;
-               si_emit_cache_flush(cmd_buffer);
-       }
         si_write_scissors(cmd_buffer->cs, 0, count,
                           cmd_buffer->state.dynamic.scissor.scissors,
                           cmd_buffer->state.dynamic.viewport.viewports,
@@ -1403,7 +1395,8 @@ radv_cmd_buffer_flush_dynamic_state(struct
radv_cmd_buffer *cmd_buffer)
         if (states & (RADV_CMD_DIRTY_DYNAMIC_VIEWPORT))
                 radv_emit_viewport(cmd_buffer);
   -     if (states & (RADV_CMD_DIRTY_DYNAMIC_SCISSOR |
RADV_CMD_DIRTY_DYNAMIC_VIEWPORT))
+       if (states & (RADV_CMD_DIRTY_DYNAMIC_SCISSOR |
RADV_CMD_DIRTY_DYNAMIC_VIEWPORT) &&
+           !cmd_buffer->device->physical_device->has_scissor_bug)
                 radv_emit_scissor(cmd_buffer);
         if (states & RADV_CMD_DIRTY_DYNAMIC_LINE_WIDTH)
@@ -3144,10 +3137,52 @@ radv_emit_draw_packets(struct radv_cmd_buffer
*cmd_buffer,
         }
   }
   +/*
+ * Vega and raven have a bug which triggers if there are multiple context
+ * register contexts active at the same time with different scissor
values.
+ *
+ * There are two possible workarounds:
+ * 1) Wait for PS_PARTIAL_FLUSH every time the scissor is changed. That
way
+ *    there is only ever 1 active set of scissor values at the same time.
+ *
+ * 2) Whenever the hardware switches contexts we have to set the scissor
+ *    registers again even if it is a noop. That way the new context gets
+ *    the correct scissor values.
+ *
+ * This implements option 2. radv_need_late_scissor_emission needs to
+ * return true on affected HW if radv_emit_all_graphics_states sets
+ * any context registers.
+ */
+static bool radv_need_late_scissor_emission(struct radv_cmd_buffer
*cmd_buffer,
+                                            bool indexed_draw)
+{
+       struct radv_cmd_state *state = &cmd_buffer->state;
+
+       if (!cmd_buffer->device->physical_device->has_scissor_bug)
+               return false;
+
+       /* Assume all state changes except  these two can imply context
rolls. */
+       if (cmd_buffer->state.dirty & ~(RADV_CMD_DIRTY_INDEX_BUFFER |
+                                       RADV_CMD_DIRTY_VERTEX_BUFFER |
+                                       RADV_CMD_DIRTY_PIPELINE))


Why are you excluding the pipeline state? Anything that has set_context_reg
will trigger a context roll, I'd expect pipelines to have those?

Because that is checked in the if directly below it: " if
(cmd_buffer->state.emitted_pipeline != cmd_buffer->state.pipeline)"

The reason I'm doing this is that with our copy&blit implementations
we have some cases of switching pipelines and immediately switching
back before a draw. The state is dirty but the pipeline is not
changed. We do the same check before emitting a pipeline.

Oh, that makes sense, sorry for the confusion.

Cheers,
Nicolai





Cheers,
Nicolai



+               return true;
+
+       if (cmd_buffer->state.emitted_pipeline !=
cmd_buffer->state.pipeline)
+               return true;
+
+       if (indexed_draw && state->pipeline->graphics.prim_restart_enable
&&
+           (state->index_type ? 0xffffffffu : 0xffffu) !=
state->last_primitive_reset_index)
+               return true;
+
+       return false;
+}
+
   static void
   radv_emit_all_graphics_states(struct radv_cmd_buffer *cmd_buffer,
                               const struct radv_draw_info *info)
   {
+       bool late_scissor_emission =
radv_need_late_scissor_emission(cmd_buffer, info->indexed);
+
         if ((cmd_buffer->state.dirty & RADV_CMD_DIRTY_FRAMEBUFFER) ||
             cmd_buffer->state.emitted_pipeline !=
cmd_buffer->state.pipeline)
                 radv_emit_rbplus_state(cmd_buffer);
@@ -3177,6 +3212,9 @@ radv_emit_all_graphics_states(struct radv_cmd_buffer
*cmd_buffer,
         radv_emit_draw_registers(cmd_buffer, info->indexed,
                                  info->instance_count > 1, info->indirect,
                                  info->indirect ? 0 : info->count);
+
+       if (late_scissor_emission)
+               radv_emit_scissor(cmd_buffer);
   }
     static void



--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.


--
Lerne, wie die Welt wirklich ist,
Aber vergiss niemals, wie sie sein sollte.
_______________________________________________
mesa-dev mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/mesa-dev

Reply via email to