C Specification
The VkMemoryDedicatedRequirements structure is defined as:
// Provided by VK_VERSION_1_1
typedef struct VkMemoryDedicatedRequirements {
VkStructureType sType;
void* pNext;
VkBool32 prefersDedicatedAllocation;
VkBool32 requiresDedicatedAllocation;
} VkMemoryDedicatedRequirements;// Provided by VK_KHR_dedicated_allocation
// Equivalent to VkMemoryDedicatedRequirements
typedef VkMemoryDedicatedRequirements VkMemoryDedicatedRequirementsKHR;Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
prefersDedicatedAllocationspecifies 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. -
requiresDedicatedAllocationspecifies that a dedicated allocation is required for this resource.
Description
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:
-
requiresDedicatedAllocationmay be VK_TRUE if thepNextchain of VkBufferCreateInfo for the call tovkCreateBufferused to create the buffer being queried included a VkExternalMemoryBufferCreateInfo structure, and any of the handle types specified in VkExternalMemoryBufferCreateInfo::handleTypesrequires dedicated allocation, as reported by vkGetPhysicalDeviceExternalBufferProperties inVkExternalBufferProperties::externalMemoryProperties.externalMemoryFeatures. Otherwise,requiresDedicatedAllocationwill be VK_FALSE. -
When the implementation sets
requiresDedicatedAllocationto VK_TRUE, it must also setprefersDedicatedAllocationto VK_TRUE. -
If VK_BUFFER_CREATE_SPARSE_BINDING_BIT was set in VkBufferCreateInfo::
flagswhenbufferwas created, then bothprefersDedicatedAllocationandrequiresDedicatedAllocationwill be VK_FALSE.
Constraints on the values returned for image resources are:
-
requiresDedicatedAllocationmay be VK_TRUE if thepNextchain 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::handleTypesrequires dedicated allocation, as reported by vkGetPhysicalDeviceImageFormatProperties2 inVkExternalImageFormatProperties::externalMemoryProperties.externalMemoryFeatures. -
requiresDedicatedAllocationmay be VK_TRUE if the image’s tiling is VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT. -
requiresDedicatedAllocationwill otherwise be VK_FALSE -
If VK_IMAGE_CREATE_SPARSE_BINDING_BIT was set in VkImageCreateInfo::
flagswhenimagewas created, then bothprefersDedicatedAllocationandrequiresDedicatedAllocationwill be VK_FALSE.
Constraints on the values returned for tensor resources are:
-
requiresDedicatedAllocationmay be VK_TRUE if thepNextchain of VkTensorCreateInfoARM for the call tovkCreateTensorARMused to create the tensor being queried included a VkExternalMemoryTensorCreateInfoARM structure, and any of the handle types specified in VkExternalMemoryTensorCreateInfoARM::handleTypesrequires dedicated allocation, as reported by vkGetPhysicalDeviceExternalTensorPropertiesARM inVkExternalTensorPropertiesARM::externalMemoryProperties.externalMemoryFeatures. -
requiresDedicatedAllocationwill otherwise be VK_FALSE. -
When the implementation sets
requiresDedicatedAllocationto VK_TRUE, it must also setprefersDedicatedAllocationto VK_TRUE.
Document Notes
For more information, see the Vulkan Specification.
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.