eden-emu/VulkanMemoryAllocator
14
0
Fork 0
mirror of https://github.com/GPUOpen-LibrariesAndSDKs/VulkanMemoryAllocator.git synced 2025-05-16 17:58:33 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

Improved logic of vmaFindMemoryTypeIndex for some cases, especially integrated GPUs.

Browse source
This commit is contained in:
Adam Sawicki 2018-04-06 17:22:33 +02:00
parent 9bb910e63c
commit 5391e6c7fa
3 changed files with 128 additions and 110 deletions
Download patch file Download diff file Expand all files Collapse all files

2
docs/html/memory_mapping.html
View file

@ -87,7 +87,7 @@ Cache control</h1>
Finding out if memory is mappable</h1>
<p>It may happen that your allocation ends up in memory that is <code>HOST_VISIBLE</code> (available for mapping) despite it wasn't explicitly requested. For example, application may work on integrated graphics with unified memory (like Intel) or allocation from video memory might have failed, so the library chose system memory as fallback.</p>
<p>You can detect this case and map such allocation to access its memory on CPU directly, instead of launching a transfer operation. In order to do that: inspect <code>allocInfo.memoryType</code>, call <a class="el" href="vk__mem__alloc_8h.html#a8701444752eb5de4464adb5a2b514bca" title="Given Memory Type Index, returns Property Flags of this memory type. ">vmaGetMemoryTypeProperties()</a>, and look for <code>VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT</code> flag in properties of that memory type.</p>
<div class="fragment"><div class="line">VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };</div><div class="line">bufCreateInfo.size = <span class="keyword">sizeof</span>(ConstantBuffer);</div><div class="line">bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;</div><div class="line"></div><div class="line"><a class="code" href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a> allocCreateInfo = {};</div><div class="line">allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">usage</a> = <a class="code" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>;</div><div class="line"></div><div class="line">VkBuffer buf;</div><div class="line"><a class="code" href="struct_vma_allocation.html">VmaAllocation</a> alloc;</div><div class="line"><a class="code" href="struct_vma_allocation_info.html">VmaAllocationInfo</a> allocInfo;</div><div class="line"><a class="code" href="vk__mem__alloc_8h.html#ac72ee55598617e8eecca384e746bab51">vmaCreateBuffer</a>(allocator, &amp;bufCreateInfo, &amp;allocCreateInfo, &amp;buf, &amp;alloc, &amp;allocInfo);</div><div class="line"></div><div class="line">VkMemoryPropertyFlags memFlags;</div><div class="line"><a class="code" href="vk__mem__alloc_8h.html#a8701444752eb5de4464adb5a2b514bca">vmaGetMemoryTypeProperties</a>(allocator, allocInfo.<a class="code" href="struct_vma_allocation_info.html#a7f6b0aa58c135e488e6b40a388dad9d5">memoryType</a>, &amp;memFlags);</div><div class="line"><span class="keywordflow">if</span>((memFlags &amp; VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)</div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in mappable memory. You can map it and access it directly.</span></div><div class="line"> <span class="keywordtype">void</span>* mappedData;</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069">vmaMapMemory</a>(allocator, alloc, &amp;mappedData);</div><div class="line"> memcpy(mappedData, &amp;constantBufferData, <span class="keyword">sizeof</span>(constantBufferData));</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#a9bc268595cb33f6ec4d519cfce81ff45">vmaUnmapMemory</a>(allocator, alloc);</div><div class="line">}</div><div class="line"><span class="keywordflow">else</span></div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in non-mappable memory.</span></div><div class="line"> <span class="comment">// You need to create CPU-side buffer in VMA_MEMORY_USAGE_CPU_ONLY and make a transfer.</span></div><div class="line">}</div></div><!-- fragment --><p>You can even use <a class="el" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f" title="Set this flag to use a memory that will be persistently mapped and retrieve pointer to it...">VMA_ALLOCATION_CREATE_MAPPED_BIT</a> flag while creating allocations that are not necessarily <code>HOST_VISIBLE</code> (e.g. using <a class="el" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>). If the allocation ends up in memory type that is <code>HOST_VISIBLE</code>, it will be persistently mapped and you can use it directly. If not, the flag is just ignored. Example:</p>
<div class="fragment"><div class="line">VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };</div><div class="line">bufCreateInfo.size = <span class="keyword">sizeof</span>(ConstantBuffer);</div><div class="line">bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;</div><div class="line"></div><div class="line"><a class="code" href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a> allocCreateInfo = {};</div><div class="line">allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">usage</a> = <a class="code" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>;</div><div class="line">allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#a7fe8d81a1ad10b2a2faacacee5b15d6d">preferredFlags</a> = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT;</div><div class="line"></div><div class="line">VkBuffer buf;</div><div class="line"><a class="code" href="struct_vma_allocation.html">VmaAllocation</a> alloc;</div><div class="line"><a class="code" href="struct_vma_allocation_info.html">VmaAllocationInfo</a> allocInfo;</div><div class="line"><a class="code" href="vk__mem__alloc_8h.html#ac72ee55598617e8eecca384e746bab51">vmaCreateBuffer</a>(allocator, &amp;bufCreateInfo, &amp;allocCreateInfo, &amp;buf, &amp;alloc, &amp;allocInfo);</div><div class="line"></div><div class="line">VkMemoryPropertyFlags memFlags;</div><div class="line"><a class="code" href="vk__mem__alloc_8h.html#a8701444752eb5de4464adb5a2b514bca">vmaGetMemoryTypeProperties</a>(allocator, allocInfo.<a class="code" href="struct_vma_allocation_info.html#a7f6b0aa58c135e488e6b40a388dad9d5">memoryType</a>, &amp;memFlags);</div><div class="line"><span class="keywordflow">if</span>((memFlags &amp; VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT) == 0)</div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in mappable memory. You can map it and access it directly.</span></div><div class="line"> <span class="keywordtype">void</span>* mappedData;</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#ad5bd1243512d099706de88168992f069">vmaMapMemory</a>(allocator, alloc, &amp;mappedData);</div><div class="line"> memcpy(mappedData, &amp;constantBufferData, <span class="keyword">sizeof</span>(constantBufferData));</div><div class="line"> <a class="code" href="vk__mem__alloc_8h.html#a9bc268595cb33f6ec4d519cfce81ff45">vmaUnmapMemory</a>(allocator, alloc);</div><div class="line">}</div><div class="line"><span class="keywordflow">else</span></div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in non-mappable memory.</span></div><div class="line"> <span class="comment">// You need to create CPU-side buffer in VMA_MEMORY_USAGE_CPU_ONLY and make a transfer.</span></div><div class="line">}</div></div><!-- fragment --><p>You can even use <a class="el" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f" title="Set this flag to use a memory that will be persistently mapped and retrieve pointer to it...">VMA_ALLOCATION_CREATE_MAPPED_BIT</a> flag while creating allocations that are not necessarily <code>HOST_VISIBLE</code> (e.g. using <a class="el" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>). If the allocation ends up in memory type that is <code>HOST_VISIBLE</code>, it will be persistently mapped and you can use it directly. If not, the flag is just ignored. Example:</p>
<div class="fragment"><div class="line">VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };</div><div class="line">bufCreateInfo.size = <span class="keyword">sizeof</span>(ConstantBuffer);</div><div class="line">bufCreateInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;</div><div class="line"></div><div class="line"><a class="code" href="struct_vma_allocation_create_info.html">VmaAllocationCreateInfo</a> allocCreateInfo = {};</div><div class="line">allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#accb8b06b1f677d858cb9af20705fa910">usage</a> = <a class="code" href="vk__mem__alloc_8h.html#aa5846affa1e9da3800e3e78fae2305ccac6b5dc1432d88647aa4cd456246eadf7">VMA_MEMORY_USAGE_GPU_ONLY</a>;</div><div class="line">allocCreateInfo.<a class="code" href="struct_vma_allocation_create_info.html#add09658ac14fe290ace25470ddd6d41b">flags</a> = <a class="code" href="vk__mem__alloc_8h.html#ad9889c10c798b040d59c92f257cae597a11da372cc3a82931c5e5d6146cd9dd1f">VMA_ALLOCATION_CREATE_MAPPED_BIT</a>;</div><div class="line"></div><div class="line">VkBuffer buf;</div><div class="line"><a class="code" href="struct_vma_allocation.html">VmaAllocation</a> alloc;</div><div class="line"><a class="code" href="struct_vma_allocation_info.html">VmaAllocationInfo</a> allocInfo;</div><div class="line"><a class="code" href="vk__mem__alloc_8h.html#ac72ee55598617e8eecca384e746bab51">vmaCreateBuffer</a>(allocator, &amp;bufCreateInfo, &amp;allocCreateInfo, &amp;buf, &amp;alloc, &amp;allocInfo);</div><div class="line"></div><div class="line"><span class="keywordflow">if</span>(allocInfo.<a class="code" href="struct_vma_allocation_info.html#adc507656149c04de7ed95d0042ba2a13">pUserData</a> != <span class="keyword">nullptr</span>)</div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in mappable memory.</span></div><div class="line"> <span class="comment">// It&#39;s persistently mapped. You can access it directly.</span></div><div class="line"> memcpy(allocInfo.<a class="code" href="struct_vma_allocation_info.html#a5eeffbe2d2f30f53370ff14aefbadbe2">pMappedData</a>, &amp;constantBufferData, <span class="keyword">sizeof</span>(constantBufferData));</div><div class="line">}</div><div class="line"><span class="keywordflow">else</span></div><div class="line">{</div><div class="line"> <span class="comment">// Allocation ended up in non-mappable memory.</span></div><div class="line"> <span class="comment">// You need to create CPU-side buffer in VMA_MEMORY_USAGE_CPU_ONLY and make a transfer.</span></div><div class="line">}</div></div><!-- fragment --> </div></div><!-- contents -->
<!-- start footer part -->
<hr class="footer"/><address class="footer"><small>