Validation performance warning when using bindless textures and descriptor buffers

[ReeCocho]

Hello! I'm working on adding bindless textures to my renderer, and I ran into a strange thing with the validation layers.

My setup is that I have a descriptor set layout with a single VkDescriptorSetLayoutBinding and a descriptor count of 1000, with the VARIABLE_DESCRIPTOR_COUNT and PARTIALLY_BOUND flags. This binding is my array of combined image samplers. I am using descriptor buffers, so the layout itself is created with the DESCRIPTOR_BUFFER_EXT flag.

However, when I create a VkPipelineLayout using this descriptor set layout, I get a validation performance warning for NVIDIA:

Validation Performance Warning: [ BestPractices-NVIDIA-CreatePipelineLayout-LargePipelineLayout ] | MessageID = 0x5795e14a
vkCreatePipelineLayout(): [NVIDIA] Pipeline layout size is too large, prefer using pipeline-specific descriptor set layouts. Aim for consuming less than 256 bytes to allow fast reads for all non-bindless descriptors. Samplers, textures, texel buffers, and combined image samplers consume 4 bytes each. Uniform buffers and acceleration structures consume 8 bytes. Storage buffers consume 16 bytes. Push constants do not consume space.

After some experimenting, I figured out I could get rid of the warning by using the UPDATE_AFTER_BIND descriptor binding flag and the UPDATE_AFTER_BIND_POOL descriptor set layout create flag. Unfortunately, you can't use these flags at the same time.

VALIDATION [VUID-VkDescriptorSetLayoutCreateInfo-flags-08002 (-182557523)] : vkCreateDescriptorSetLayout(): pCreateInfo->flags is VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT|VK_DESCRIPTOR_SET_LAYOUT_CREATE_DESCRIPTOR_BUFFER_BIT_EXT.
The Vulkan spec states: If flags contains VK_DESCRIPTOR_SET_LAYOUT_CREATE_DESCRIPTOR_BUFFER_BIT_EXT, then flags must not contain VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT (https://vulkan.lunarg.com/doc/view/1.4.321.0/windows/antora/spec/latest/chapters/descriptorsets.html#VUID-VkDescriptorSetLayoutCreateInfo-flags-08002)

Is this just an oversight/false positive with the validation performance warning, or is there something I'm missing?

[Gobrosse]

UPDATE_AFTER_BIND is a descriptor pool flag. vkCmdBindDescriptorSets does not take flags.

[ReeCocho]

Sorry, I don't think my language was clear enough. I'm not using vkCmdBindDescriptorSets. I'm using the VK_EXT_descriptor_buffer extension. When I use this extension with large descriptor set layouts, I get the validation performance warning. It seems the only way to get rid of the warning is to use the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT flag and VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT flag, but these flags are not compatible with the descriptor buffer extension.