VkMemoryDedicatedRequirements

The VkMemoryDedicatedRequirements structure is defined as:

typedef struct VkMemoryDedicatedRequirements {
    VkStructureType sType;
    void* pNext;
    VkBool32 prefersDedicatedAllocation;
    VkBool32 requiresDedicatedAllocation;
} VkMemoryDedicatedRequirements;

pub struct MemoryDedicatedRequirements {
    s_type: vk::StructureType,
    p_next: *mut c_void,
    prefers_dedicated_allocation: vk::Bool32,
    requires_dedicated_allocation: vk::Bool32,
}

typedef VkMemoryDedicatedRequirements VkMemoryDedicatedRequirementsKHR;

type MemoryDedicatedRequirementsKHR = vk::MemoryDedicatedRequirements;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• prefersDedicatedAllocation specifies that the implementation would prefer a dedicated allocation for this resource. The application is still free to suballocate the resource but it may get better performance if a dedicated allocation is used.
• requiresDedicatedAllocation specifies that a dedicated allocation is required for this resource.

To determine the dedicated allocation requirements of a buffer or image or tensor resource, add a VkMemoryDedicatedRequirements structure to the pNext chain of the VkMemoryRequirements2 structure passed as the pMemoryRequirements parameter of vkGetBufferMemoryRequirements2, vkGetTensorMemoryRequirementsARM, vkGetDeviceBufferMemoryRequirements, vkGetDeviceImageMemoryRequirements, or vkGetImageMemoryRequirements2 respectively.

Constraints on the values returned for buffer resources are:

• requiresDedicatedAllocation may be VK_TRUE if the pNext chain of VkBufferCreateInfo for the call to vkCreateBuffer used to create the buffer being queried included a VkExternalMemoryBufferCreateInfo structure, and any of the handle types specified in VkExternalMemoryBufferCreateInfo::handleTypes requires dedicated allocation, as reported by vkGetPhysicalDeviceExternalBufferProperties in VkExternalBufferProperties::externalMemoryProperties.externalMemoryFeatures. Otherwise, requiresDedicatedAllocation will be VK_FALSE.
• When the implementation sets requiresDedicatedAllocation to VK_TRUE, it must also set prefersDedicatedAllocation to VK_TRUE.
• If VK_BUFFER_CREATE_SPARSE_BINDING_BIT was set in VkBufferCreateInfo::flags when buffer was created, then both prefersDedicatedAllocation and requiresDedicatedAllocation will be VK_FALSE.

Constraints on the values returned for image resources are:

• requiresDedicatedAllocation may be VK_TRUE if the pNext chain of VkImageCreateInfo for the call to vkCreateImage used to create the image being queried included a VkExternalMemoryImageCreateInfo structure, and any of the handle types specified in VkExternalMemoryImageCreateInfo::handleTypes requires dedicated allocation, as reported by vkGetPhysicalDeviceImageFormatProperties2 in VkExternalImageFormatProperties::externalMemoryProperties.externalMemoryFeatures.
• requiresDedicatedAllocation may be VK_TRUE if the image’s tiling is VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT.
• requiresDedicatedAllocation will otherwise be VK_FALSE
• If VK_IMAGE_CREATE_SPARSE_BINDING_BIT was set in VkImageCreateInfo::flags when image was created, then both prefersDedicatedAllocation and requiresDedicatedAllocation will be VK_FALSE.

Constraints on the values returned for tensor resources are:

• requiresDedicatedAllocation may be VK_TRUE if the pNext chain of VkTensorCreateInfoARM for the call to vkCreateTensorARM used to create the tensor being queried included a VkExternalMemoryTensorCreateInfoARM structure, and any of the handle types specified in VkExternalMemoryTensorCreateInfoARM::handleTypes requires dedicated allocation, as reported by vkGetPhysicalDeviceExternalTensorPropertiesARM in VkExternalTensorPropertiesARM::externalMemoryProperties.externalMemoryFeatures.
• requiresDedicatedAllocation will otherwise be VK_FALSE.
• When the implementation sets requiresDedicatedAllocation to VK_TRUE, it must also set prefersDedicatedAllocation to VK_TRUE.