Added support for VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT without HOST_VISIBLE. Improved empty block heuristics.

docs/html/group__layer1.html

@@ -203,7 +203,8 @@ Functions</h2></td></tr>
 </td></tr>
 <tr><td class="fieldname"><a id="ggad9889c10c798b040d59c92f257cae597ae443691ef3d077c0dc3de5576ac4c312"></a>VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT&#160;</td><td class="fielddoc"><p>Set this flag to use a memory that will be persistently mapped and retrieve pointer to it. </p>
 <p>Pointer to mapped memory will be returned through <a class="el" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2" title="Pointer to the beginning of this allocation as mapped data. Null if this alloaction is not persistent...">VmaAllocationInfo::pMappedData</a>. You cannot map the memory on your own as multiple mappings of a single <code>VkDeviceMemory</code> are illegal.</p>
-<p>If <a class="el" href="struct_vma_allocation_create_info.html#a6272c0555cfd1fe28bff1afeb6190150" title="Pool that this allocation should be created in. ">VmaAllocationCreateInfo::pool</a> is not null, usage of this flag must match usage of flag <code>VMA_POOL_CREATE_PERSISTENT_MAP_BIT</code> used during pool creation. </p>
+<p>If <a class="el" href="struct_vma_allocation_create_info.html#a6272c0555cfd1fe28bff1afeb6190150" title="Pool that this allocation should be created in. ">VmaAllocationCreateInfo::pool</a> is not null, usage of this flag must match usage of flag <code>VMA_POOL_CREATE_PERSISTENT_MAP_BIT</code> used during pool creation.</p>
+<p>Is it valid to use this flag for allocation made from memory type that is not <code>HOST_VISIBLE</code>. This flag is then ignored and memory is not mapped. This is useful if you need an allocation that is efficient to use on GPU (<code>DEVICE_LOCAL</code>) and still want to map it directly if possible on platforms that support it (e.g. Intel GPU). </p>
 </td></tr>
 <tr><td class="fieldname"><a id="ggad9889c10c798b040d59c92f257cae597a5f436af6c8fe8540573a6d22627a6fd2"></a>VMA_ALLOCATION_CREATE_CAN_BECOME_LOST_BIT&#160;</td><td class="fielddoc"><p>Allocation created with this flag can become lost as a result of another allocation with <code>VMA_ALLOCATION_CREATE_CAN_MAKE_OTHER_LOST_BIT</code> flag, so you must check it before use.</p>
 <p>To check if allocation is not lost, call <a class="el" href="group__layer2.html#ga86dd08aba8633bfa4ad0df2e76481d8b" title="Returns current information about specified allocation. ">vmaGetAllocationInfo()</a> and check if <a class="el" href="struct_vma_allocation_info.html#ae0bfb7dfdf79a76ffefc9a94677a2f67" title="Handle to Vulkan memory object. ">VmaAllocationInfo::deviceMemory</a> is not <code>VK_NULL_HANDLE</code>.</p>

src/vk_mem_alloc.h

@@ -685,6 +685,12 @@ typedef enum VmaAllocationCreateFlagBits {
 
     If VmaAllocationCreateInfo::pool is not null, usage of this flag must match
     usage of flag `VMA_POOL_CREATE_PERSISTENT_MAP_BIT` used during pool creation.
+
+    Is it valid to use this flag for allocation made from memory type that is not
+    `HOST_VISIBLE`. This flag is then ignored and memory is not mapped. This is
+    useful if you need an allocation that is efficient to use on GPU
+    (`DEVICE_LOCAL`) and still want to map it directly if possible on platforms that
+    support it (e.g. Intel GPU).
     */
     VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT = 0x00000004,
     /** Allocation created with this flag can become lost as a result of another
@@ -5315,8 +5321,8 @@ VkResult VmaBlockVector::Allocate(
     VmaAllocation* pAllocation)
 {
     // Validate flags.
-    if(((createInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0) !=
+    if(createInfo.pool != VK_NULL_HANDLE &&
-        (m_BlockVectorType == VMA_BLOCK_VECTOR_TYPE_MAPPED))
+        ((createInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0) != (m_BlockVectorType == VMA_BLOCK_VECTOR_TYPE_MAPPED))
     {
         VMA_ASSERT(0 && "Usage of VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT must match VMA_POOL_CREATE_PERSISTENT_MAP_BIT.");
         return VK_ERROR_OUT_OF_DEVICE_MEMORY;
@@ -5548,7 +5554,19 @@ void VmaBlockVector::Free(
                 m_HasEmptyBlock = true;
             }
         }
-        // Must be called after srcBlockIndex is used, because later it may become invalid!
+        // pBlock didn't become empty, but we have another empty block - find and free that one.
+        // (This is optional, heuristics.)
+        else if(m_HasEmptyBlock)
+        {
+            VmaDeviceMemoryBlock* pLastBlock = m_Blocks.back();
+            if(pLastBlock->m_Metadata.IsEmpty() && m_Blocks.size() > m_MinBlockCount)
+            {
+                pBlockToDelete = pLastBlock;
+                m_Blocks.pop_back();
+                m_HasEmptyBlock = false;
+            }
+        }
+
         IncrementallySortBlocks();
     }
 
@@ -6313,17 +6331,31 @@ VkResult VmaAllocator_T::AllocateMemoryOfType(
     VmaBlockVector* const blockVector = m_pBlockVectors[memTypeIndex][blockVectorType];
     VMA_ASSERT(blockVector);
 
-    const VkDeviceSize preferredBlockSize = blockVector->GetPreferredBlockSize();
+    VmaAllocationCreateInfo finalCreateInfo = createInfo;
-    // Heuristics: Allocate own memory if requested size if greater than half of preferred block size.
-    const bool ownMemory =
-        (createInfo.flags & VMA_ALLOCATION_CREATE_OWN_MEMORY_BIT) != 0 ||
-        VMA_DEBUG_ALWAYS_OWN_MEMORY ||
-        ((createInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) == 0 &&
-            vkMemReq.size > preferredBlockSize / 2);
 
-    if(ownMemory)
+    if(VMA_DEBUG_ALWAYS_OWN_MEMORY)
     {
-        if((createInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
+        finalCreateInfo.flags |= VMA_ALLOCATION_CREATE_OWN_MEMORY_BIT;
+    }
+
+    // Heuristics: Allocate own memory if requested size if greater than half of preferred block size.
+    const VkDeviceSize preferredBlockSize = blockVector->GetPreferredBlockSize();
+    if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) == 0 &&
+        vkMemReq.size > preferredBlockSize / 2)
+    {
+        finalCreateInfo.flags |= VMA_ALLOCATION_CREATE_OWN_MEMORY_BIT;
+    }
+
+    // If memory type is not HOST_VISIBLE, disable PERSISTENT_MAP.
+    if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0 &&
+        (m_MemProps.memoryTypes[memTypeIndex].propertyFlags & VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)
+    {
+        finalCreateInfo.flags &= ~VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT;
+    }
+
+    if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_OWN_MEMORY_BIT) != 0)
+    {
+        if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
         {
             return VK_ERROR_OUT_OF_DEVICE_MEMORY;
         }
@@ -6333,8 +6365,8 @@ VkResult VmaAllocator_T::AllocateMemoryOfType(
                 vkMemReq.size,
                 suballocType,
                 memTypeIndex,
-                (createInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0,
+                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0,
-                createInfo.pUserData,
+                finalCreateInfo.pUserData,
                 pAllocation);
         }
     }
@@ -6344,7 +6376,7 @@ VkResult VmaAllocator_T::AllocateMemoryOfType(
             VK_NULL_HANDLE, // hCurrentPool
             m_CurrentFrameIndex.load(),
             vkMemReq,
-            createInfo,
+            finalCreateInfo,
             suballocType,
             pAllocation);
         if(res == VK_SUCCESS)
@@ -6353,12 +6385,18 @@ VkResult VmaAllocator_T::AllocateMemoryOfType(
         }
 
         // 5. Try own memory.
+        if((finalCreateInfo.flags & VMA_ALLOCATION_CREATE_NEVER_ALLOCATE_BIT) != 0)
+        {
+            return VK_ERROR_OUT_OF_DEVICE_MEMORY;
+        }
+        else
+        {
             res = AllocateOwnMemory(
                 vkMemReq.size,
                 suballocType,
                 memTypeIndex,
-            (createInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0,
+                (finalCreateInfo.flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0,
-            createInfo.pUserData,
+                finalCreateInfo.pUserData,
                 pAllocation);
             if(res == VK_SUCCESS)
             {
@@ -6373,6 +6411,7 @@ VkResult VmaAllocator_T::AllocateMemoryOfType(
                 return res;
             }
         }
+    }
 }
 
 VkResult VmaAllocator_T::AllocateOwnMemory(
@@ -7394,11 +7433,6 @@ VkResult vmaFindMemoryTypeIndex(
         break;
     }
 
-    if((pAllocationCreateInfo->flags & VMA_ALLOCATION_CREATE_PERSISTENT_MAP_BIT) != 0)
-    {
-        requiredFlags |= VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;
-    }
-
     *pMemoryTypeIndex = UINT32_MAX;
     uint32_t minCost = UINT32_MAX;
     for(uint32_t memTypeIndex = 0, memTypeBit = 1;