[Mesa-dev] [PATCH v2 7/7] anv: Implement the Skylake stencil PMA optimization
Nanley Chery
nanleychery at gmail.com
Tue Feb 14 19:01:00 UTC 2017
On Tue, Feb 14, 2017 at 10:53:37AM -0800, Jason Ekstrand wrote:
> On Tue, Feb 14, 2017 at 10:35 AM, Nanley Chery <nanleychery at gmail.com>
> wrote:
>
> > On Mon, Feb 13, 2017 at 08:45:47PM -0800, Jason Ekstrand wrote:
> > > On Mon, Feb 13, 2017 at 6:13 PM, Jason Ekstrand <jason at jlekstrand.net>
> > > wrote:
> > >
> > > > 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.
> > > >
> > >
> > > I did a bunch more runs. It looks like it helps somewhere between 0 and
> > > 1%. Not as much as I saw earlier, but it's definitely non-negative.
> > >
> >
> > Although I've confirmed that the fix is enabled in Dota 2, I'm also not
> > seeing any major changes on my SKL GT4. I get positive and negative
> > changes in FPS, but it's all < 1% and seemingly noise.
> >
> > With the commit message updated with your new findings, this patch is
> > Reviewed-by: Nanley Chery <nanley.g.chery at intel.com>
> >
>
> Here's what I wrote:
>
> Unfortunately, this doesn't substantially improve the performance of any
> known apps. With Dota 2 on my Sky Lake gt4, it seems help by somewhere
> between 0% and 1% but there's enough noise that it's hard to get a clear
> picture.
>
Looks good to me.
-Nanley
>
>
> > > --Jason
> > >
> > >
> > > > --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_buffe
> > > >> r));
> > > >> > }
> > > >> > #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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