[Mesa-dev] [PATCH v2] anv: Allow PMA optimization to be enabled in secondary command buffers

[Alex Smith]

On 5 January 2018 at 21:43, Jason Ekstrand <jason at jlekstrand.net> wrote:

> On Fri, Jan 5, 2018 at 9:06 AM, Alex Smith <asmith at feralinteractive.com>
> wrote:
>
>> This was never enabled in secondary buffers because hiz_enabled was
>> never set to true for those.
>>
>> If the app provides a framebuffer in the inheritance info when beginning
>> a secondary buffer, we can determine if HiZ is enabled and therefore
>> allow the PMA optimization to be enabled within the command buffer.
>>
>> This improves performance by ~13% on an internal benchmark on Skylake.
>>
>
> Are you sure this is Sky Lake and not Broadwell?  We've never measured the
> stencil PMA to help anything before.  Neat!
>

Yep, this was on HD 530 specifically.


> Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
>
>
>> v2: Use anv_cmd_buffer_get_depth_stencil_view().
>>
>> Signed-off-by: Alex Smith <asmith at feralinteractive.com>
>> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
>> ---
>>  src/intel/vulkan/genX_cmd_buffer.c | 22 +++++++++++++++++++++-
>>  1 file changed, 21 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/intel/vulkan/genX_cmd_buffer.c
>> b/src/intel/vulkan/genX_cmd_buffer.c
>> index 0bd3874db7..b7253d5251 100644
>> --- a/src/intel/vulkan/genX_cmd_buffer.c
>> +++ b/src/intel/vulkan/genX_cmd_buffer.c
>> @@ -977,11 +977,31 @@ genX(BeginCommandBuffer)(
>>           anv_render_pass_from_handle(pBeginInfo->pInheritanceInfo->re
>> nderPass);
>>        cmd_buffer->state.subpass =
>>           &cmd_buffer->state.pass->subpasses[pBeginInfo->pInheritanceI
>> nfo->subpass];
>> -      cmd_buffer->state.framebuffer = NULL;
>> +
>> +      /* This is optional in the inheritance info. */
>> +      cmd_buffer->state.framebuffer =
>> +         anv_framebuffer_from_handle(pBeginInfo->pInheritanceInfo->f
>> ramebuffer);
>>
>
> FYI: The only reason why we were always setting framebuffer to NULL for
> secondaries was because most of the CTS tests specify a framebuffer and I
> wanted our testing to run without the framebuffer because that's the more
> difficult case.  (It's easy to forget that framebuffer may be NULL.)  I
> knew it was a potential performance issue but no one was heavily using
> secondaries in the wild up until now.  Thanks for getting this working!
>

All of our Vulkan games use secondary command buffers, but we also always
set the framebuffer in the inheritance info :)


>
>
>>
>>        result = genX(cmd_buffer_setup_attachments)(cmd_buffer,
>>
>>  cmd_buffer->state.pass, NULL);
>>
>> +      /* Record that HiZ is enabled if we can. */
>> +      if (cmd_buffer->state.framebuffer) {
>> +         const struct anv_image_view * const iview =
>> +            anv_cmd_buffer_get_depth_stencil_view(cmd_buffer);
>> +
>> +         if (iview) {
>> +            VkImageLayout layout =
>> +                cmd_buffer->state.subpass->dep
>> th_stencil_attachment.layout;
>> +
>> +            enum isl_aux_usage aux_usage =
>> +               anv_layout_to_aux_usage(&cmd_buffer->device->info,
>> iview->image,
>> +                                       VK_IMAGE_ASPECT_DEPTH_BIT,
>> layout);
>> +
>> +            cmd_buffer->state.hiz_enabled = aux_usage ==
>> ISL_AUX_USAGE_HIZ;
>> +         }
>> +      }
>> +
>>        cmd_buffer->state.dirty |= ANV_CMD_DIRTY_RENDER_TARGETS;
>>     }
>>
>> --
>> 2.13.6
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>
>
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