VK_EXT_memory_budget

Other Extension Metadata

Last Modified Date

2018-10-08

Contributors

Jeff Bolz, NVIDIA
Jeff Juliano, NVIDIA

While running a Vulkan application, other processes on the machine might also be attempting to use the same device memory, which can pose problems. This extension adds support for querying the amount of memory used and the total memory budget for a memory heap. The values returned by this query are implementation-dependent and can depend on a variety of factors including operating system and system load.

The VkPhysicalDeviceMemoryBudgetPropertiesEXT::heapBudget values can be used as a guideline for how much total memory from each heap the current process can use at any given time, before allocations may start failing or causing performance degradation. The values may change based on other activity in the system that is outside the scope and control of the Vulkan implementation.

The VkPhysicalDeviceMemoryBudgetPropertiesEXT::heapUsage will display the current process estimated heap usage.

With this information, the idea is for an application at some interval (once per frame, per few seconds, etc) to query heapBudget and heapUsage. From here the application can notice if it is over budget and decide how it wants to handle the memory situation (free it, move to host memory, changing mipmap levels, etc). This extension is designed to be used in concert with VK_EXT_memory_priority to help with this part of memory management.

New Structures

Extending VkPhysicalDeviceMemoryProperties2:
- VkPhysicalDeviceMemoryBudgetPropertiesEXT

New Enum Constants

VK_EXT_MEMORY_BUDGET_EXTENSION_NAME
VK_EXT_MEMORY_BUDGET_SPEC_VERSION
Extending VkStructureType:
- VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_BUDGET_PROPERTIES_EXT

Version History

Revision 1, 2018-10-08 (Jeff Bolz)
- Initial revision