[dxvk] Order allocations to relocate by offset

Potentially improves the situation where a chunk cannot be relocated
in its entirely by freeing up a larger block of memory at the end of
the chunk, which may be enough to service a subsequent defrag attempt
of a different chunk.

src/dxvk/dxvk_memory.cpp

@@ -489,12 +489,12 @@ namespace dxvk {
     for (uint32_t i = 0; i < count; i++) {
       auto iter = m_entries.begin();
 
-      if (totalSize && totalSize + iter->second.size > size)
+      if (totalSize && totalSize + iter->first.size > size)
         break;
 
-      totalSize += iter->second.size;
+      totalSize += iter->first.size;
 
-      result.push_back({ iter->first, iter->second.mode });
+      result.push_back(std::move(iter->second));
       m_entries.erase(iter);
     }
 
@@ -504,10 +504,12 @@ namespace dxvk {
 
   void DxvkRelocationList::addResource(
           Rc<DxvkPagedResource>&&     resource,
-          DxvkAllocationModes         mode,
-          VkDeviceSize                size) {
+    const DxvkResourceAllocation*     allocation,
+          DxvkAllocationModes         mode) {
     std::lock_guard lock(m_mutex);
-    m_entries.emplace(std::move(resource), Entry { mode, size });
+    m_entries.emplace(std::piecewise_construct,
+      std::forward_as_tuple(allocation->getMemoryInfo()),
+      std::forward_as_tuple(std::move(resource), mode));
   }
 
 
@@ -2175,7 +2177,7 @@ namespace dxvk {
         continue;
 
       // Acquired the resource, add it to the relocation list.
-      m_relocations.addResource(std::move(resource), mode, a->m_size);
+      m_relocations.addResource(std::move(resource), a, mode);
     }
   }
 

src/dxvk/dxvk_memory.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <map>
 #include <memory>
 
 #include "dxvk_access.h"
@@ -985,6 +986,10 @@ namespace dxvk {
    * \brief Relocation entry
    */
   struct DxvkRelocationEntry {
+    DxvkRelocationEntry() = default;
+    DxvkRelocationEntry(Rc<DxvkPagedResource>&& r, DxvkAllocationModes m)
+    : resource(std::move(r)), mode(m) { }
+
     /// Resource to relocate
     Rc<DxvkPagedResource> resource;
     /// Resource to relocate
@@ -1023,13 +1028,13 @@ namespace dxvk {
      * \brief Adds relocation entry to the list
      *
      * \param [in] resource Resource to add
+     * \param [in] allocation Resource storage
      * \param [in] mode Allocation mode
-     * \param [in] size Allocation size
      */
     void addResource(
             Rc<DxvkPagedResource>&&     resource,
-            DxvkAllocationModes         mode,
-            VkDeviceSize                size);
+      const DxvkResourceAllocation*     allocation,
+            DxvkAllocationModes         mode);
 
     /**
      * \brief Clears list
@@ -1046,14 +1051,22 @@ namespace dxvk {
 
   private:
 
-    struct Entry {
-      DxvkAllocationModes mode = 0u;
-      VkDeviceSize        size = 0u;
+    struct RelocationOrdering {
+      bool operator () (const DxvkResourceMemoryInfo& a, const DxvkResourceMemoryInfo& b) const {
+        // Keep chunks together, then order by offset in order to increase
+        // the likelihood of freeing up a contiguous block of memory.
+        if (a.memory < b.memory) return true;
+        if (a.memory > b.memory) return false;
+        return a.offset > b.offset;
+      }
     };
 
-    dxvk::mutex                               m_mutex;
-    std::unordered_map<Rc<DxvkPagedResource>,
-      Entry, RcHash>                          m_entries;
+    dxvk::mutex                 m_mutex;
+
+    std::map<
+      DxvkResourceMemoryInfo,
+      DxvkRelocationEntry,
+      RelocationOrdering>       m_entries;
 
   };