By default, allocations are laid out in memory blocks next to each other if possible (considering required alignment, bufferImageGranularity, and nonCoherentAtomSize).
Define macro VMA_DEBUG_MARGIN to some non-zero value (e.g. 16) to enforce specified number of bytes as a margin before and after every allocation.
Define macro VMA_DEBUG_MARGIN to some non-zero value (e.g. 16) to enforce specified number of bytes as a margin after every allocation.
If your bug goes away after enabling margins, it means it may be caused by memory being overwritten outside of allocation boundaries. It is not 100% certain though. Change in application behavior may also be caused by different order and distribution of allocations across memory blocks after margins are applied.
-The margin is applied also before first and after last allocation in a block. It may occur only once between two adjacent allocations.
Margins work with all types of memory.
Margin is applied only to allocations made out of memory blocks and not to dedicated allocations, which have their own memory block of specific size. It is thus not applied to allocations made using VMA_ALLOCATION_CREATE_DEDICATED_MEMORY_BIT flag or those automatically decided to put into dedicated allocations, e.g. due to its large size or recommended by VK_KHR_dedicated_allocation extension. Margins are also not active in custom pools created with VMA_POOL_CREATE_BUDDY_ALGORITHM_BIT flag.
Margins appear in JSON dump as part of free space.
Note that enabling margins increases memory usage and fragmentation.
+Margins do not apply to Virtual allocator.
You can additionally define macro VMA_DEBUG_DETECT_CORRUPTION to 1 to enable validation of contents of the margins.
When this feature is enabled, number of bytes specified as VMA_DEBUG_MARGIN (it must be multiply of 4) before and after every allocation is filled with a magic number. This idea is also know as "canary". Memory is automatically mapped and unmapped if necessary.
When this feature is enabled, number of bytes specified as VMA_DEBUG_MARGIN (it must be multiply of 4) after every allocation is filled with a magic number. This idea is also know as "canary". Memory is automatically mapped and unmapped if necessary.
This number is validated automatically when the allocation is destroyed. If it is not equal to the expected value, VMA_ASSERT() is executed. It clearly means that either CPU or GPU overwritten the memory outside of boundaries of the allocation, which indicates a serious bug.
You can also explicitly request checking margins of all allocations in all memory blocks that belong to specified memory types by using function vmaCheckCorruption(), or in memory blocks that belong to specified custom pool, by using function vmaCheckPoolCorruption().
Margin validation (corruption detection) works only for memory types that are HOST_VISIBLE and HOST_COHERENT.
Flags to be passed as VmaVirtualBlockCreateInfo::flags.
+Flags to be passed as VmaVirtualBlockCreateInfo::flags.
Flags to be passed as VmaVirtualBlockCreateInfo::flags. See VmaVirtualBlockCreateFlagBits.
+Flags to be passed as VmaVirtualBlockCreateInfo::flags. See VmaVirtualBlockCreateFlagBits.
Flags to be passed as VmaVirtualBlockCreateInfo::flags.
+Flags to be passed as VmaVirtualBlockCreateInfo::flags.
| Enumerator | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| VMA_VIRTUAL_BLOCK_CREATE_LINEAR_ALGORITHM_BIT | Enables alternative, linear allocation algorithm in this virtual block. Specify this flag to enable linear allocation algorithm, which always creates new allocations after last one and doesn't reuse space from allocations freed in between. It trades memory consumption for simplified algorithm and data structure, which has better performance and uses less memory for metadata. diff --git a/docs/html/search/all_5.js b/docs/html/search/all_5.js index 0bcc998..00173a3 100644 --- a/docs/html/search/all_5.js +++ b/docs/html/search/all_5.js @@ -1,4 +1,4 @@ var searchData= [ - ['flags_0',['flags',['../struct_vma_allocator_create_info.html#a392ea2ecbaff93f91a7c49f735ad4346',1,'VmaAllocatorCreateInfo::flags()'],['../struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b',1,'VmaAllocationCreateInfo::flags()'],['../struct_vma_pool_create_info.html#a8405139f63d078340ae74513a59f5446',1,'VmaPoolCreateInfo::flags()'],['../struct_vma_defragmentation_info2.html#a53e844ee5633e229cf6daf14b2d9fff9',1,'VmaDefragmentationInfo2::flags()'],['../struct_vma_virtual_block_create_info.html#a5838b15c053a0370420e4e1d82d09c09',1,'VmaVirtualBlockCreateInfo::flags()'],['../struct_vma_virtual_allocation_create_info.html#ab10e16956cc4bf20ced9de77d1129ea4',1,'VmaVirtualAllocationCreateInfo::flags()']]] + ['flags_0',['flags',['../struct_vma_allocator_create_info.html#a392ea2ecbaff93f91a7c49f735ad4346',1,'VmaAllocatorCreateInfo::flags()'],['../struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b',1,'VmaAllocationCreateInfo::flags()'],['../struct_vma_pool_create_info.html#a8405139f63d078340ae74513a59f5446',1,'VmaPoolCreateInfo::flags()'],['../struct_vma_defragmentation_info2.html#a53e844ee5633e229cf6daf14b2d9fff9',1,'VmaDefragmentationInfo2::flags()'],['../struct_vma_virtual_block_create_info.html#aaab9bf7e2d228c02ab6d90a72a6e6912',1,'VmaVirtualBlockCreateInfo::flags()'],['../struct_vma_virtual_allocation_create_info.html#ab10e16956cc4bf20ced9de77d1129ea4',1,'VmaVirtualAllocationCreateInfo::flags()']]] ]; diff --git a/docs/html/search/variables_4.js b/docs/html/search/variables_4.js index 0bcc998..00173a3 100644 --- a/docs/html/search/variables_4.js +++ b/docs/html/search/variables_4.js @@ -1,4 +1,4 @@ var searchData= [ - ['flags_0',['flags',['../struct_vma_allocator_create_info.html#a392ea2ecbaff93f91a7c49f735ad4346',1,'VmaAllocatorCreateInfo::flags()'],['../struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b',1,'VmaAllocationCreateInfo::flags()'],['../struct_vma_pool_create_info.html#a8405139f63d078340ae74513a59f5446',1,'VmaPoolCreateInfo::flags()'],['../struct_vma_defragmentation_info2.html#a53e844ee5633e229cf6daf14b2d9fff9',1,'VmaDefragmentationInfo2::flags()'],['../struct_vma_virtual_block_create_info.html#a5838b15c053a0370420e4e1d82d09c09',1,'VmaVirtualBlockCreateInfo::flags()'],['../struct_vma_virtual_allocation_create_info.html#ab10e16956cc4bf20ced9de77d1129ea4',1,'VmaVirtualAllocationCreateInfo::flags()']]] + ['flags_0',['flags',['../struct_vma_allocator_create_info.html#a392ea2ecbaff93f91a7c49f735ad4346',1,'VmaAllocatorCreateInfo::flags()'],['../struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b',1,'VmaAllocationCreateInfo::flags()'],['../struct_vma_pool_create_info.html#a8405139f63d078340ae74513a59f5446',1,'VmaPoolCreateInfo::flags()'],['../struct_vma_defragmentation_info2.html#a53e844ee5633e229cf6daf14b2d9fff9',1,'VmaDefragmentationInfo2::flags()'],['../struct_vma_virtual_block_create_info.html#aaab9bf7e2d228c02ab6d90a72a6e6912',1,'VmaVirtualBlockCreateInfo::flags()'],['../struct_vma_virtual_allocation_create_info.html#ab10e16956cc4bf20ced9de77d1129ea4',1,'VmaVirtualAllocationCreateInfo::flags()']]] ]; diff --git a/docs/html/struct_vma_virtual_block_create_info-members.html b/docs/html/struct_vma_virtual_block_create_info-members.html index 231cc5c..732a4cd 100644 --- a/docs/html/struct_vma_virtual_block_create_info-members.html +++ b/docs/html/struct_vma_virtual_block_create_info-members.html @@ -68,7 +68,7 @@ $(function() {This is the complete list of members for VmaVirtualBlockCreateInfo, including all inherited members.
| ||||||||||||
| VkDeviceSize | size | ||||||||||||
| Total size of the virtual block. More... | |||||||||||||
| VmaVirtualBlockCreateFlagBits | flags | ||||||||||||
| Use combination of VmaVirtualBlockCreateFlagBits. More... | |||||||||||||
| VmaVirtualBlockCreateFlags | flags | ||||||||||||
| Use combination of VmaVirtualBlockCreateFlagBits. More... | |||||||||||||
| const VkAllocationCallbacks * | pAllocationCallbacks | ||||||||||||
| Custom CPU memory allocation callbacks. Optional. More... | |||||||||||||
| VmaVirtualBlockCreateFlagBits VmaVirtualBlockCreateInfo::flags | +VmaVirtualBlockCreateFlags VmaVirtualBlockCreateInfo::flags |