[Mesa-dev] [PATCH 2/2] anv: Implement the Sky Lake stencil PMA optimization
Nanley Chery
nanleychery at gmail.com
Thu Feb 2 21:45:37 UTC 2017
On Thu, Feb 02, 2017 at 01:37:56PM -0800, Nanley Chery wrote:
> On Thu, Feb 02, 2017 at 12:53:33PM -0800, Jason Ekstrand wrote:
> > On Thu, Feb 2, 2017 at 10:55 AM, Nanley Chery <nanleychery at gmail.com> wrote:
> >
> > > On Wed, Feb 01, 2017 at 10:11:42PM -0800, Jason Ekstrand wrote:
> > > > This improves the performance of Dota 2 on my Sky Lake Skull Canyon
> > > > machine by about 2-3%.
> > > > ---
> > > > src/intel/vulkan/anv_private.h | 1 +
> > > > src/intel/vulkan/gen8_cmd_buffer.c | 155 ++++++++++++++++++++++++++++++
> > > ++++++-
> > > > src/intel/vulkan/genX_pipeline.c | 6 +-
> > > > 3 files changed, 156 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/src/intel/vulkan/anv_private.h
> > > b/src/intel/vulkan/anv_private.h
> > > > index 5fe4dd8..e7ad351 100644
> > > > --- a/src/intel/vulkan/anv_private.h
> > > > +++ b/src/intel/vulkan/anv_private.h
> > > > @@ -1475,6 +1475,7 @@ struct anv_pipeline {
> > > > bool writes_depth;
> > > > bool depth_test_enable;
> > > > bool writes_stencil;
> > > > + bool stencil_test_enable;
> > > > bool depth_clamp_enable;
> > > > bool kill_pixel;
> > > >
> > > > diff --git a/src/intel/vulkan/gen8_cmd_buffer.c
> > > b/src/intel/vulkan/gen8_cmd_buffer.c
> > > > index b877e27..553f0c3 100644
> > > > --- a/src/intel/vulkan/gen8_cmd_buffer.c
> > > > +++ b/src/intel/vulkan/gen8_cmd_buffer.c
> > > > @@ -157,16 +157,39 @@ __emit_sf_state(struct anv_cmd_buffer *cmd_buffer)
> > > > void
> > > > genX(cmd_buffer_enable_pma_fix)(struct anv_cmd_buffer *cmd_buffer,
> > > bool enable)
> > > > {
> > > > -#if GEN_GEN == 8
> > > > if (cmd_buffer->state.pma_fix_enabled == enable)
> > > > return;
> > > >
> > > > + cmd_buffer->state.pma_fix_enabled = enable;
> > > > +
> > > > + /* According to the Broadwell PIPE_CONTROL documentation, software
> > > should
> > > > + * emit a PIPE_CONTROL with the CS Stall and Depth Cache Flush bits
> > > set
> > > > + * prior to the LRI. If stencil buffer writes are enabled, then a
> > > Render
> > > > + * Cache Flush is also necessary.
> > > > + *
> > > > + * The Sky Lake docs say to use a depth stall rather than a command
> > > > + * streamer stall. However, the hardware seems to violently
> > > disagree.
> > > > + * A full command streamer stall seems to be needed in both cases.
> > > > + */
> > > > anv_batch_emit(&cmd_buffer->batch, GENX(PIPE_CONTROL), pc) {
> > > > pc.DepthCacheFlushEnable = true;
> > > > pc.CommandStreamerStallEnable = true;
> > > > pc.RenderTargetCacheFlushEnable = true;
> > > > }
> > > >
> > > > +#if GEN_GEN == 9
> > > > +
> > > > + uint32_t cache_mode;
> > > > + anv_pack_struct(&cache_mode, GENX(CACHE_MODE_0),
> > > > + .STCPMAOptimizationEnable = enable,
> > > > + .STCPMAOptimizationEnableMask = true);
> > > > + anv_batch_emit(&cmd_buffer->batch, GENX(MI_LOAD_REGISTER_IMM), lri)
> > > {
> > > > + lri.RegisterOffset = GENX(CACHE_MODE_0_num);
> > > > + lri.DataDWord = cache_mode;
> > > > + }
> > > > +
> > > > +#elif GEN_GEN == 8
> > > > +
> > > > uint32_t cache_mode;
> > > > anv_pack_struct(&cache_mode, GENX(CACHE_MODE_1),
> > > > .NPPMAFixEnable = enable,
> > > > @@ -178,18 +201,20 @@ genX(cmd_buffer_enable_pma_fix)(struct
> > > anv_cmd_buffer *cmd_buffer, bool enable)
> > > > lri.DataDWord = cache_mode;
> > > > }
> > > >
> > > > +#endif /* GEN_GEN == 8 */
> > > > +
> > > > /* After the LRI, a PIPE_CONTROL with both the Depth Stall and Depth
> > > Cache
> > > > * Flush bits is often necessary. We do it regardless because it's
> > > easier.
> > > > * The render cache flush is also necessary if stencil writes are
> > > enabled.
> > > > + *
> > > > + * Again, the Sky Lake docs give a different set of flushes but the
> > > BDW
> > > > + * flushes seem to work just as well.
> > > > */
> > > > anv_batch_emit(&cmd_buffer->batch, GENX(PIPE_CONTROL), pc) {
> > > > pc.DepthStallEnable = true;
> > > > pc.DepthCacheFlushEnable = true;
> > > > pc.RenderTargetCacheFlushEnable = true;
> > > > }
> > > > -
> > > > - cmd_buffer->state.pma_fix_enabled = enable;
> > > > -#endif /* GEN_GEN == 8 */
> > > > }
> > > >
> > > > static inline bool
> > > > @@ -289,6 +314,124 @@ want_depth_pma_fix(struct anv_cmd_buffer
> > > *cmd_buffer)
> > > > wm_prog_data->computed_depth_mode != PSCDEPTH_OFF;
> > > > }
> > > >
> > > > +static inline bool
> > > > +want_stencil_pma_fix(struct anv_cmd_buffer *cmd_buffer)
> > > > +{
> > > > + assert(GEN_GEN == 9);
> > > > +
> > > > + /* From the Sky Lake PRM Vol. 2c CACHE_MODE_1::STC PMA Optimization
> > > Enable:
> > > > + *
> > > > + * Clearing this bit will force the STC cache to wait for pending
> > > > + * retirement of pixels at the HZ-read stage and do the STC-test
> > > for
> > > > + * Non-promoted, R-computed and Computed depth modes instead of
> > > > + * postponing the STC-test to RCPFE.
> > > > + *
> > > > + * STC_TEST_EN = 3DSTATE_STENCIL_BUFFER::STENCIL_BUFFER_ENABLE &&
> > > > + * 3DSTATE_WM_DEPTH_STENCIL::StencilTestEnable
> > > > + *
> > > > + * STC_WRITE_EN = 3DSTATE_STENCIL_BUFFER::STENCIL_BUFFER_ENABLE
> > > &&
> > > > + * (3DSTATE_WM_DEPTH_STENCIL::Stencil Buffer
> > > Write Enable &&
> > > > + * 3DSTATE_DEPTH_BUFFER::STENCIL_WRITE_ENABLE)
> > > > + *
> > > > + * COMP_STC_EN = STC_TEST_EN &&
> > > > + * 3DSTATE_PS_EXTRA::PixelShaderComputesStencil
> > > > + *
> > > > + * SW parses the pipeline states to generate the following logical
> > > > + * signal indicating if PMA FIX can be enabled.
> > > > + *
> > > > + * STC_PMA_OPT =
> > > > + * 3DSTATE_WM::ForceThreadDispatch != 1 &&
> > > > + * !(3DSTATE_RASTER::ForceSampleCount != NUMRASTSAMPLES_0) &&
> > > > + * 3DSTATE_DEPTH_BUFFER::SURFACE_TYPE != NULL &&
> > > > + * 3DSTATE_DEPTH_BUFFER::HIZ Enable &&
> > > > + * !(3DSTATE_WM::EDSC_Mode == 2) &&
> > > > + * 3DSTATE_PS_EXTRA::PixelShaderValid &&
> > > > + * !(3DSTATE_WM_HZ_OP::DepthBufferClear ||
> > > > + * 3DSTATE_WM_HZ_OP::DepthBufferResolve ||
> > > > + * 3DSTATE_WM_HZ_OP::Hierarchical Depth Buffer Resolve
> > > Enable ||
> > > > + * 3DSTATE_WM_HZ_OP::StencilBufferClear) &&
> > > > + * (COMP_STC_EN || STC_WRITE_EN) &&
> > > > + * ((3DSTATE_PS_EXTRA::PixelShaderKillsPixels ||
> > > > + * 3DSTATE_WM::ForceKillPix == ON ||
> > > > + * 3DSTATE_PS_EXTRA::oMask Present to RenderTarget ||
> > > > + * 3DSTATE_PS_BLEND::AlphaToCoverageEnable ||
> > > > + * 3DSTATE_PS_BLEND::AlphaTestEnable ||
> > > > + * 3DSTATE_WM_CHROMAKEY::ChromaKeyKillEnable) ||
> > > > + * (3DSTATE_PS_EXTRA::Pixel Shader Computed Depth mode !=
> > > PSCDEPTH_OFF))
> > > > + */
> > > > +
> > > > + /* These are always true:
> > > > + * 3DSTATE_WM::ForceThreadDispatch != 1 &&
> > > > + * !(3DSTATE_RASTER::ForceSampleCount != NUMRASTSAMPLES_0)
> > > > + */
> > > > +
> > > > + /* We only enable the PMA fix if HiZ is enabled. However, if HiZ is
> > > > + * *not* enabled and we don't set this bit there is no harm.
> > > Therefore,
> > > > + * we can just treat the NULL framebuffer case as has_hiz == false
> > > and
> > > > + * everything will work just fine.
> > > > + */
> > > > + if (cmd_buffer->state.framebuffer == NULL)
> > > > + return false;
> > > > +
> > > > + /* (3DSTATE_DEPTH_BUFFER::SURFACE_TYPE != NULL) &&
> > > > + * 3DSTATE_DEPTH_BUFFER::HIZ Enable
> > > > + */
> > > > + const struct anv_image_view *ds_iview =
> > > > + anv_cmd_buffer_get_depth_stencil_view(cmd_buffer);
> > > > + if (!ds_iview || ds_iview->image->aux_usage != ISL_AUX_USAGE_HIZ)
> > >
> > > I think there's an error here. For depth buffers, anv_image::aux_usage
> > > only indicates if there is an auxiliary HiZ buffer present. It does not
> > > indicate that the HiZ buffer is being used within a render pass. For
> > > that you'd have to check anv_attachment_state::aux_usage.
> > >
> >
> > So things just got more interesting... The Vulkan spec only requires that
> > the render pass provided to pInheritanceInfo for the vkBeginCommandBuffer
> > of a secondary command buffer to be "compatible" with the render pass
> > provided to vkCmdBeginRenderPass. The rules for compatibility explicitly
> > allow the initial and final layouts of the attachments to differ. This
> > means that, if HiZ usage within a render pass is determined by the initial
> > layout, we can never know if HiZ is enabled in a secondary command buffer
> > and we always have to leave the PMA stall off. That's fairly brutal to
> > apps.
>
> That is interesting. I'm glad you found this. Perhaps we can get around
> this by computing part of the PMA fix at the start of the subpass, and
> the latter portion at the draw call?
>
That seems to be what your v2 patches are doing, so the problem is
solved right?
-Nanley
> >
> > How bad would it be to enable HiZ within the render pass for the case where
> > they use the GENERAL layout and then resolve at the end? They used the
> > GENERAL layout so they know they won't get fantastic performance so maybe
> > that's ok?
> >
>
> Now that we've seen a benchmark out in the wild that uses depth input
> attachments, I think we'll want the GENERAL layout to be fast and for
> our software handling it to be straight-forward. I think we can
> accomplish this by adding HiZ R/W support to BLORP. A local series of
> mine that enables HiZ for input attachments takes a step towards this by
> getting rid of the read-depth-through-HiZ situation we currently have
> for the GENERAL layout.
>
> -Nanley
>
> > Either way, I'll respin and make it correct. We can sort this issue out and
> > hopefully give secondary command buffer users their 2-3% later.
> >
> > --Jason
> >
> >
> > > -Nanley
> > >
> > > > + return false;
> > > > +
> > > > + /* 3DSTATE_PS_EXTRA::PixelShaderValid */
> > > > + struct anv_pipeline *pipeline = cmd_buffer->state.pipeline;
> > > > + if (!anv_pipeline_has_stage(pipeline, MESA_SHADER_FRAGMENT))
> > > > + return false;
> > > > +
> > > > + /* !(3DSTATE_WM::EDSC_Mode == 2) */
> > > > + const struct brw_wm_prog_data *wm_prog_data =
> > > get_wm_prog_data(pipeline);
> > > > + if (wm_prog_data->early_fragment_tests)
> > > > + return false;
> > > > +
> > > > + /* We never use anv_pipeline for HiZ ops so this is trivially true:
> > > > + * !(3DSTATE_WM_HZ_OP::DepthBufferClear ||
> > > > + * 3DSTATE_WM_HZ_OP::DepthBufferResolve ||
> > > > + * 3DSTATE_WM_HZ_OP::Hierarchical Depth Buffer Resolve Enable ||
> > > > + * 3DSTATE_WM_HZ_OP::StencilBufferClear)
> > > > + */
> > > > +
> > > > + /* 3DSTATE_STENCIL_BUFFER::STENCIL_BUFFER_ENABLE &&
> > > > + * 3DSTATE_WM_DEPTH_STENCIL::StencilTestEnable
> > > > + */
> > > > + const bool stc_test_en =
> > > > + (ds_iview->image->aspects & VK_IMAGE_ASPECT_STENCIL_BIT) &&
> > > > + pipeline->stencil_test_enable;
> > > > +
> > > > + /* 3DSTATE_STENCIL_BUFFER::STENCIL_BUFFER_ENABLE &&
> > > > + * (3DSTATE_WM_DEPTH_STENCIL::Stencil Buffer Write Enable &&
> > > > + * 3DSTATE_DEPTH_BUFFER::STENCIL_WRITE_ENABLE)
> > > > + */
> > > > + const bool stc_write_en =
> > > > + (ds_iview->image->aspects & VK_IMAGE_ASPECT_STENCIL_BIT) &&
> > > > + pipeline->writes_stencil;
> > > > +
> > > > + /* STC_TEST_EN && 3DSTATE_PS_EXTRA::PixelShaderComputesStencil */
> > > > + const bool comp_stc_en = stc_test_en &&
> > > wm_prog_data->computed_stencil;
> > > > +
> > > > + /* COMP_STC_EN || STC_WRITE_EN */
> > > > + if (!(comp_stc_en || stc_write_en))
> > > > + return false;
> > > > +
> > > > + /* (3DSTATE_PS_EXTRA::PixelShaderKillsPixels ||
> > > > + * 3DSTATE_WM::ForceKillPix == ON ||
> > > > + * 3DSTATE_PS_EXTRA::oMask Present to RenderTarget ||
> > > > + * 3DSTATE_PS_BLEND::AlphaToCoverageEnable ||
> > > > + * 3DSTATE_PS_BLEND::AlphaTestEnable ||
> > > > + * 3DSTATE_WM_CHROMAKEY::ChromaKeyKillEnable) ||
> > > > + * (3DSTATE_PS_EXTRA::Pixel Shader Computed Depth mode !=
> > > PSCDEPTH_OFF)
> > > > + */
> > > > + return pipeline->kill_pixel ||
> > > > + wm_prog_data->computed_depth_mode != PSCDEPTH_OFF;
> > > > +}
> > > > +
> > > > void
> > > > genX(cmd_buffer_flush_dynamic_state)(struct anv_cmd_buffer *cmd_buffer)
> > > > {
> > > > @@ -398,6 +541,7 @@ genX(cmd_buffer_flush_dynamic_state)(struct
> > > anv_cmd_buffer *cmd_buffer)
> > > > }
> > > >
> > > > if (cmd_buffer->state.dirty & (ANV_CMD_DIRTY_PIPELINE |
> > > > + ANV_CMD_DIRTY_RENDER_TARGETS |
> > > > ANV_CMD_DIRTY_DYNAMIC_STENCIL_COMPARE_MASK
> > > |
> > > > ANV_CMD_DIRTY_DYNAMIC_STENCIL_WRITE_MASK
> > > |
> > > > ANV_CMD_DIRTY_DYNAMIC_STENCIL_REFERENCE))
> > > {
> > > > @@ -423,6 +567,9 @@ genX(cmd_buffer_flush_dynamic_state)(struct
> > > anv_cmd_buffer *cmd_buffer)
> > > >
> > > > anv_batch_emit_merge(&cmd_buffer->batch, dwords,
> > > > pipeline->gen9.wm_depth_stencil);
> > > > +
> > > > + genX(cmd_buffer_enable_pma_fix)(cmd_buffer,
> > > > + want_stencil_pma_fix(cmd_buffe
> > > r));
> > > > }
> > > > #endif
> > > >
> > > > diff --git a/src/intel/vulkan/genX_pipeline.c
> > > b/src/intel/vulkan/genX_pipeline.c
> > > > index 3f701f3..3087037 100644
> > > > --- a/src/intel/vulkan/genX_pipeline.c
> > > > +++ b/src/intel/vulkan/genX_pipeline.c
> > > > @@ -742,6 +742,7 @@ emit_ds_state(struct anv_pipeline *pipeline,
> > > > * to make sure it's initialized to something useful.
> > > > */
> > > > pipeline->writes_stencil = false;
> > > > + pipeline->stencil_test_enable = false;
> > > > pipeline->writes_depth = false;
> > > > pipeline->depth_test_enable = false;
> > > > memset(depth_stencil_dw, 0, sizeof(depth_stencil_dw));
> > > > @@ -757,6 +758,7 @@ emit_ds_state(struct anv_pipeline *pipeline,
> > > >
> > > > VkPipelineDepthStencilStateCreateInfo info = *pCreateInfo;
> > > > sanitize_ds_state(&info, &pipeline->writes_stencil, ds_aspects);
> > > > + pipeline->stencil_test_enable = info.stencilTestEnable;
> > > > pipeline->writes_depth = info.depthWriteEnable;
> > > > pipeline->depth_test_enable = info.depthTestEnable;
> > > >
> > > > @@ -1514,8 +1516,8 @@ compute_kill_pixel(struct anv_pipeline *pipeline,
> > > > const struct brw_wm_prog_data *wm_prog_data =
> > > get_wm_prog_data(pipeline);
> > > >
> > > > /* This computes the KillPixel portion of the computation for
> > > whether or
> > > > - * not we want to enable the PMA fix on gen8. It's given by this
> > > chunk of
> > > > - * the giant formula:
> > > > + * not we want to enable the PMA fix on gen8 or gen9. It's given by
> > > this
> > > > + * chunk of the giant formula:
> > > > *
> > > > * (3DSTATE_PS_EXTRA::PixelShaderKillsPixels ||
> > > > * 3DSTATE_PS_EXTRA::oMask Present to RenderTarget ||
> > > > --
> > > > 2.5.0.400.gff86faf
> > > >
> > > > _______________________________________________
> > > > mesa-dev mailing list
> > > > mesa-dev at lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
> > >
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