VK_NV_dedicated_allocation(3)

# VK_NV_dedicated_allocation(3) Manual Page

## Name

VK_NV_dedicated_allocation - device extension

Loading… please wait.

## Registered Extension Number

27

## Revision

1

## Ratification Status

Not ratified

## Extension and Version Dependencies

None

## Deprecation State

- Deprecated by VK_KHR_dedicated_allocation extension

  - Which in turn was promoted to Vulkan 1.1

## Contact

- Jeff Bolz jeffbolznv

## Other Extension Metadata

Last Modified Date

  2016-05-31

IP Status

  No known IP claims.

Contributors

  - Jeff Bolz, NVIDIA

## Description

This extension allows device memory to be allocated for a particular buffer or image resource, which on some devices can significantly improve the performance of that resource. Normal device memory allocations must support memory aliasing and sparse binding, which could interfere with optimizations like framebuffer compression or efficient page table usage. This is important for render targets and very large resources, but need not (and probably should not) be used for smaller resources that can benefit from suballocation.

This extension adds a few small structures to resource creation and memory allocation: a new structure that flags whether am image/buffer will have a dedicated allocation, and a structure indicating the image or buffer that an allocation will be bound to.

## New Structures

- Extending VkBufferCreateInfo:

  - VkDedicatedAllocationBufferCreateInfoNV

- Extending VkImageCreateInfo:

  - VkDedicatedAllocationImageCreateInfoNV

- Extending VkMemoryAllocateInfo:

  - VkDedicatedAllocationMemoryAllocateInfoNV

## New Enum Constants

- `VK_NV_DEDICATED_ALLOCATION_EXTENSION_NAME`

- `VK_NV_DEDICATED_ALLOCATION_SPEC_VERSION`

- Extending VkStructureType:

  - `VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_BUFFER_CREATE_INFO_NV`

  - `VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_IMAGE_CREATE_INFO_NV`

  - `VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_MEMORY_ALLOCATE_INFO_NV`

## Examples

        // Create an image with
        // VkDedicatedAllocationImageCreateInfoNV::dedicatedAllocation
        // set to VK_TRUE

        VkDedicatedAllocationImageCreateInfoNV dedicatedImageInfo =
        {
            .sType = VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_IMAGE_CREATE_INFO_NV,
            .pNext = NULL,
            .dedicatedAllocation = VK_TRUE,
        };

        VkImageCreateInfo imageCreateInfo =
        {
            .sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
            .pNext = &dedicatedImageInfo
            // Other members set as usual
        };

        VkImage image;
        VkResult result = vkCreateImage(
            device,
            &imageCreateInfo,
            NULL,               // pAllocator
            &image);

        VkMemoryRequirements memoryRequirements;
        vkGetImageMemoryRequirements(
            device,
            image,
            &memoryRequirements);

        // Allocate memory with VkDedicatedAllocationMemoryAllocateInfoNV::image
        // pointing to the image we are allocating the memory for

        VkDedicatedAllocationMemoryAllocateInfoNV dedicatedInfo =
        {
            .sType = VK_STRUCTURE_TYPE_DEDICATED_ALLOCATION_MEMORY_ALLOCATE_INFO_NV,
            .pNext = NULL,
            .image = image,
            .buffer = VK_NULL_HANDLE,
        };

        VkMemoryAllocateInfo memoryAllocateInfo =
        {
            .sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
            .pNext = &dedicatedInfo,
            .allocationSize = memoryRequirements.size,
            .memoryTypeIndex = FindMemoryTypeIndex(memoryRequirements.memoryTypeBits),
        };

        VkDeviceMemory memory;
        vkAllocateMemory(
            device,
            &memoryAllocateInfo,
            NULL,               // pAllocator
            &memory);

        // Bind the image to the memory

        vkBindImageMemory(
            device,
            image,
            memory,
            0);

## Version History

- Revision 1, 2016-05-31 (Jeff Bolz)

  - Internal revisions

## See Also

VkDedicatedAllocationBufferCreateInfoNV, VkDedicatedAllocationImageCreateInfoNV, VkDedicatedAllocationMemoryAllocateInfoNV

## Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.

## Copyright

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0