[Mesa-dev] [PATCH v2 7/7] anv: Implement the Skylake stencil PMA optimization

Jason Ekstrand jason at jlekstrand.net
Tue Feb 14 02:13:45 UTC 2017


On Mon, Feb 13, 2017 at 5:00 PM, Nanley Chery <nanleychery at gmail.com> wrote:

> On Fri, Feb 10, 2017 at 11:02:21AM -0800, Jason Ekstrand wrote:
> > This improves the performance of Dota 2 on my Sky Lake Skull Canyon
> > machine by about 2-3%.
> >
>
> This patch looks good. Could we compare our setup and testing in the
> office? I can't reproduce these numbers.
>

I'll have to do more runs.  At the moment, I'm not seeing a large boost but
I'll get a larger sample size and see if it's visible.

--Jason


> -Nanley
>
> > Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> > ---
> >  src/intel/vulkan/anv_private.h     |   1 +
> >  src/intel/vulkan/gen8_cmd_buffer.c | 157 ++++++++++++++++++++++++++++++
> ++++++-
> >  src/intel/vulkan/genX_pipeline.c   |   6 +-
> >  3 files changed, 158 insertions(+), 6 deletions(-)
> >
> > diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_
> private.h
> > index fa6032e..25c9c93 100644
> > --- a/src/intel/vulkan/anv_private.h
> > +++ b/src/intel/vulkan/anv_private.h
> > @@ -1482,6 +1482,7 @@ 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 0628f3a..59fd537 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 Skylake 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 Skylake 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
> > @@ -281,6 +306,126 @@ 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 Skylake 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 we know for certain that HiZ is
> enabled.
> > +    * If we don't know whether HiZ is enabled or not, we disable the
> PMA fix
> > +    * and there is no harm.
> > +    *
> > +    * (3DSTATE_DEPTH_BUFFER::SURFACE_TYPE != NULL) &&
> > +    * 3DSTATE_DEPTH_BUFFER::HIZ Enable
> > +    */
> > +   if (!cmd_buffer->state.hiz_enabled)
> > +      return false;
> > +
> > +   /* We can't possibly know if HiZ is enabled without the framebuffer
> */
> > +   assert(cmd_buffer->state.framebuffer);
> > +
> > +   /* HiZ is enabled so we had better have a depth buffer with HiZ */
> > +   const struct anv_image_view *ds_iview =
> > +      anv_cmd_buffer_get_depth_stencil_view(cmd_buffer);
> > +   assert(ds_iview && ds_iview->image->aux_usage == ISL_AUX_USAGE_HIZ);
> > +
> > +   /* 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)
> >  {
> > @@ -390,6 +535,7 @@ 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))
> {
> > @@ -415,6 +561,9 @@ 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_
> buffer));
> >     }
> >  #endif
> >
> > diff --git a/src/intel/vulkan/genX_pipeline.c b/src/intel/vulkan/genX_
> pipeline.c
> > index d2af8b9..3b0ae08 100644
> > --- a/src/intel/vulkan/genX_pipeline.c
> > +++ b/src/intel/vulkan/genX_pipeline.c
> > @@ -784,6 +784,7 @@ 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));
> > @@ -799,6 +800,7 @@ 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;
> >
> > @@ -1556,8 +1558,8 @@ 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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