System: Improve texture recycling when changing rewind/runahead settings

Fix suprious failures when changing rewind settings when low on VRAM.

src/core/gpu_backend.cpp

@@ -332,21 +332,32 @@ bool GPUBackend::AllocateMemorySaveStates(std::span<System::MemorySaveState> sta
       for (size_t i = 0; i < states.size(); i++)
         g_gpu_device->RecycleTexture(std::move(states[i].vram_texture));
 
+      // Maximize potential for texture reuse by flushing the current command buffer.
+      g_gpu_device->WaitForGPUIdle();
+
       for (size_t i = 0; i < states.size(); i++)
       {
         if (!backend->AllocateMemorySaveState(states[i], error))
         {
-          // Free anything that was allocated.
+          // Try flushing the pool.
-          for (size_t j = 0; j <= i; i++)
+          WARNING_LOG("Failed to allocate memory save state texture, trying flushing pool.");
+          g_gpu_device->PurgeTexturePool();
+          g_gpu_device->WaitForGPUIdle();
+          if (!backend->AllocateMemorySaveState(states[i], error))
           {
-            states[j].state_data.deallocate();
+            // Free anything that was allocated.
-            states[j].vram_texture.reset();
+            for (size_t j = 0; j <= i; i++)
-            result = false;
+            {
-            return;
+              states[j].state_data.deallocate();
+              states[j].vram_texture.reset();
+              result = false;
+              return;
+            }
           }
         }
       }
 
+      backend->RestoreDeviceContext();
       result = true;
     },
     true, false);

src/core/hotkeys.cpp

@@ -59,7 +59,7 @@ static void HotkeyModifyResolutionScale(s32 increment)
 
   if (System::IsValid())
   {
-    System::ClearMemorySaveStates(true);
+    System::ClearMemorySaveStates(true, false);
     GPUThread::UpdateSettings(true, false);
   }
 }
@@ -373,7 +373,7 @@ DEFINE_HOTKEY("TogglePGXP", TRANSLATE_NOOP("Hotkeys", "Graphics"), TRANSLATE_NOO
               [](s32 pressed) {
                 if (!pressed && System::IsValid())
                 {
-                  System::ClearMemorySaveStates(true);
+                  System::ClearMemorySaveStates(true, true);
 
                   g_settings.gpu_pgxp_enable = !g_settings.gpu_pgxp_enable;
                   GPUThread::UpdateSettings(true, false);
@@ -451,7 +451,7 @@ DEFINE_HOTKEY("TogglePGXPDepth", TRANSLATE_NOOP("Hotkeys", "Graphics"),
                   if (!g_settings.gpu_pgxp_enable)
                     return;
 
-                  System::ClearMemorySaveStates(true);
+                  System::ClearMemorySaveStates(true, true);
 
                   g_settings.gpu_pgxp_depth_buffer = !g_settings.gpu_pgxp_depth_buffer;
                   GPUThread::UpdateSettings(true, false);
@@ -471,7 +471,7 @@ DEFINE_HOTKEY("TogglePGXPCPU", TRANSLATE_NOOP("Hotkeys", "Graphics"), TRANSLATE_
                   if (!g_settings.gpu_pgxp_enable)
                     return;
 
-                  System::ClearMemorySaveStates(true);
+                  System::ClearMemorySaveStates(true, true);
 
                   // GPU thread is unchanged
                   g_settings.gpu_pgxp_cpu = !g_settings.gpu_pgxp_cpu;

src/core/system.cpp

@@ -1167,7 +1167,7 @@ DiscRegion System::GetRegionForPsf(const char* path)
 
 void System::RecreateGPU(GPURenderer renderer)
 {
-  FreeMemoryStateTextures();
+  FreeMemoryStateStorage(false);
   StopMediaCapture();
 
   Error error;
@@ -1177,7 +1177,7 @@ void System::RecreateGPU(GPURenderer renderer)
     Panic("Failed to switch renderer.");
   }
 
-  ClearMemorySaveStates(true);
+  ClearMemorySaveStates(true, false);
 }
 
 void System::LoadSettings(bool display_osd_messages)
@@ -1954,7 +1954,7 @@ void System::DestroySystem()
   if (g_settings.inhibit_screensaver)
     PlatformMisc::ResumeScreensaver();
 
-  FreeMemoryStateStorage();
+  FreeMemoryStateStorage(false);
 
   Cheats::UnloadAll();
   PCDrv::Shutdown();
@@ -2495,13 +2495,13 @@ System::MemorySaveState& System::PopMemoryState()
   return s_state.memory_save_states[s_state.memory_save_state_front];
 }
 
-bool System::AllocateMemoryStates(size_t state_count)
+bool System::AllocateMemoryStates(size_t state_count, bool recycle_old_textures)
 {
   DEV_LOG("Allocating {} memory save state slots", state_count);
 
   if (state_count != s_state.memory_save_states.size())
   {
-    FreeMemoryStateStorage();
+    FreeMemoryStateStorage(recycle_old_textures);
     s_state.memory_save_states.resize(state_count);
   }
 
@@ -2522,7 +2522,7 @@ bool System::AllocateMemoryStates(size_t state_count)
     ERROR_LOG("Failed to allocate {} memory save states: {}", s_state.memory_save_states.size(),
               error.GetDescription());
     ERROR_LOG("Disabling runahead/rewind.");
-    FreeMemoryStateStorage();
+    FreeMemoryStateStorage(false);
     s_state.runahead_frames = 0;
     s_state.memory_save_state_front = 0;
     s_state.memory_save_state_count = 0;
@@ -2536,48 +2536,16 @@ bool System::AllocateMemoryStates(size_t state_count)
   return true;
 }
 
-void System::ClearMemorySaveStates(bool reallocate_resources)
+void System::ClearMemorySaveStates(bool reallocate_resources, bool recycle_textures)
 {
   s_state.memory_save_state_front = 0;
   s_state.memory_save_state_count = 0;
 
   if (reallocate_resources && !s_state.memory_save_states.empty())
-    AllocateMemoryStates(s_state.memory_save_states.size());
+    AllocateMemoryStates(s_state.memory_save_states.size(), recycle_textures);
 }
 
-void System::FreeMemoryStateTextures()
+void System::FreeMemoryStateStorage(bool recycle_textures)
-{
-  // TODO: use non-copyable function, that way we don't need to store raw pointers
-  std::vector<GPUTexture*> textures;
-  bool gpu_thread_synced = false;
-
-  for (MemorySaveState& mss : s_state.memory_save_states)
-  {
-    if ((mss.vram_texture || !mss.gpu_state_data.empty()) && !gpu_thread_synced)
-    {
-      gpu_thread_synced = true;
-      GPUThread::SyncGPUThread(true);
-    }
-
-    if (mss.vram_texture)
-    {
-      if (textures.empty())
-        textures.reserve(s_state.memory_save_states.size());
-
-      textures.push_back(mss.vram_texture.release());
-    }
-  }
-
-  if (!textures.empty())
-  {
-    GPUThread::RunOnThread([textures = std::move(textures)]() mutable {
-      for (GPUTexture* texture : textures)
-        g_gpu_device->RecycleTexture(std::unique_ptr<GPUTexture>(texture));
-    });
-  }
-}
-
-void System::FreeMemoryStateStorage()
 {
   // TODO: use non-copyable function, that way we don't need to store raw pointers
   std::vector<GPUTexture*> textures;
@@ -2607,9 +2575,14 @@ void System::FreeMemoryStateStorage()
 
   if (!textures.empty())
   {
-    GPUThread::RunOnThread([textures = std::move(textures)]() mutable {
+    GPUThread::RunOnThread([textures = std::move(textures), recycle_textures]() mutable {
       for (GPUTexture* texture : textures)
-        g_gpu_device->RecycleTexture(std::unique_ptr<GPUTexture>(texture));
+      {
+        if (recycle_textures)
+          g_gpu_device->RecycleTexture(std::unique_ptr<GPUTexture>(texture));
+        else
+          delete texture;
+      }
     });
   }
 
@@ -2919,7 +2892,7 @@ bool System::LoadStateFromBuffer(const SaveStateBuffer& buffer, Error* error, bo
   if (g_settings.HasAnyPerGameMemoryCards())
     UpdatePerGameMemoryCards();
 
-  ClearMemorySaveStates(false);
+  ClearMemorySaveStates(false, false);
 
   // Updating game/loading settings can turn on hardcore mode. Catch this.
   Achievements::DisableHardcoreMode();
@@ -4005,7 +3978,7 @@ bool System::InsertMedia(const char* path)
   if (IsGPUDumpPath(path)) [[unlikely]]
     return ChangeGPUDump(path);
 
-  ClearMemorySaveStates(true);
+  ClearMemorySaveStates(true, true);
 
   Error error;
   std::unique_ptr<CDImage> image = CDImage::Open(path, g_settings.cdrom_load_image_patches, &error);
@@ -4044,7 +4017,7 @@ bool System::InsertMedia(const char* path)
 
 void System::RemoveMedia()
 {
-  ClearMemorySaveStates(true);
+  ClearMemorySaveStates(true, true);
   CDROM::RemoveMedia(false);
 }
 
@@ -4254,7 +4227,7 @@ bool System::SwitchMediaSubImage(u32 index)
   if (!CDROM::HasMedia())
     return false;
 
-  ClearMemorySaveStates(true);
+  ClearMemorySaveStates(true, true);
 
   std::unique_ptr<CDImage> image = CDROM::RemoveMedia(true);
   Assert(image);
@@ -4308,7 +4281,7 @@ void System::CheckForSettingsChanges(const Settings& old_settings)
 {
   if (IsValid())
   {
-    ClearMemorySaveStates(false);
+    ClearMemorySaveStates(false, false);
 
     if (g_settings.cpu_overclock_active != old_settings.cpu_overclock_active ||
         (g_settings.cpu_overclock_active &&
@@ -4448,7 +4421,8 @@ void System::CheckForSettingsChanges(const Settings& old_settings)
       GPUThread::UpdateSettings(true, false);
 
       // NOTE: Must come after the GPU thread settings update, otherwise it allocs the wrong size textures.
-      ClearMemorySaveStates(true);
+      const bool use_existing_textures = (g_settings.gpu_resolution_scale == old_settings.gpu_resolution_scale);
+      ClearMemorySaveStates(true, use_existing_textures);
 
       if (IsPaused())
         GPUThread::PresentCurrentFrame();
@@ -4884,7 +4858,8 @@ void System::CalculateRewindMemoryUsage(u32 num_saves, u32 resolution_scale, u64
 
 void System::UpdateMemorySaveStateSettings()
 {
-  FreeMemoryStateStorage();
+  const bool any_memory_states_active = (g_settings.IsRunaheadEnabled() || g_settings.rewind_enable);
+  FreeMemoryStateStorage(any_memory_states_active);
 
   if (IsReplayingGPUDump()) [[unlikely]]
   {
@@ -4926,7 +4901,7 @@ void System::UpdateMemorySaveStateSettings()
 
   // allocate storage for memory save states
   if (num_slots > 0)
-    AllocateMemoryStates(num_slots);
+    AllocateMemoryStates(num_slots, true);
 
   // reenter execution loop, don't want to try to save a state now if runahead was turned off
   InterruptExecution();
@@ -5024,7 +4999,7 @@ bool System::DoRunahead()
     s_state.runahead_replay_frames = s_state.memory_save_state_count;
 
     // and throw away all the states, forcing us to catch up below
-    ClearMemorySaveStates(false);
+    ClearMemorySaveStates(false, false);
 
     // run the frames with no audio
     SPU::SetAudioOutputMuted(true);

src/core/system.h

@@ -418,7 +418,7 @@ void RequestDisplaySize(float scale = 0.0f);
 // Memory Save States (Rewind and Runahead)
 //////////////////////////////////////////////////////////////////////////
 void CalculateRewindMemoryUsage(u32 num_saves, u32 resolution_scale, u64* ram_usage, u64* vram_usage);
-void ClearMemorySaveStates(bool reallocate_resources);
+void ClearMemorySaveStates(bool reallocate_resources, bool recycle_textures);
 void SetRunaheadReplayFlag();
 
 /// Shared socket multiplexer, used by PINE/GDB/etc.

src/core/system_private.h

@@ -26,9 +26,8 @@ struct MemorySaveState
 MemorySaveState& AllocateMemoryState();
 MemorySaveState& GetFirstMemoryState();
 MemorySaveState& PopMemoryState();
-bool AllocateMemoryStates(size_t state_count);
+bool AllocateMemoryStates(size_t state_count, bool recycle_old_textures);
-void FreeMemoryStateTextures();
+void FreeMemoryStateStorage(bool recycle_texture);
-void FreeMemoryStateStorage();
 void LoadMemoryState(MemorySaveState& mss, bool update_display);
 void SaveMemoryState(MemorySaveState& mss);