texture_cache: Make sure that readback images are downloaded in time (#3593)

src/video_core/renderer_vulkan/vk_rasterizer.cpp

@@ -34,8 +34,9 @@ Rasterizer::Rasterizer(const Instance& instance_, Scheduler& scheduler_,
                        AmdGpu::Liverpool* liverpool_)
     : instance{instance_}, scheduler{scheduler_}, page_manager{this},
       buffer_cache{instance, scheduler, liverpool_, texture_cache, page_manager},
-      texture_cache{instance, scheduler, buffer_cache, page_manager}, liverpool{liverpool_},
-      memory{Core::Memory::Instance()}, pipeline_cache{instance, scheduler, liverpool} {
+      texture_cache{instance, scheduler, liverpool_, buffer_cache, page_manager},
+      liverpool{liverpool_}, memory{Core::Memory::Instance()},
+      pipeline_cache{instance, scheduler, liverpool} {
     if (!Config::nullGpu()) {
         liverpool->BindRasterizer(this);
     }

src/video_core/texture_cache/texture_cache.cpp

@@ -6,6 +6,7 @@
 #include "common/assert.h"
 #include "common/config.h"
 #include "common/debug.h"
+#include "common/polyfill_thread.h"
 #include "common/scope_exit.h"
 #include "core/memory.h"
 #include "video_core/buffer_cache/buffer_cache.h"
@@ -22,9 +23,10 @@ static constexpr u64 PageShift = 12;
 static constexpr u64 NumFramesBeforeRemoval = 32;
 
 TextureCache::TextureCache(const Vulkan::Instance& instance_, Vulkan::Scheduler& scheduler_,
-                           BufferCache& buffer_cache_, PageManager& tracker_)
-    : instance{instance_}, scheduler{scheduler_}, buffer_cache{buffer_cache_}, tracker{tracker_},
-      blit_helper{instance, scheduler},
+                           AmdGpu::Liverpool* liverpool_, BufferCache& buffer_cache_,
+                           PageManager& tracker_)
+    : instance{instance_}, scheduler{scheduler_}, liverpool{liverpool_},
+      buffer_cache{buffer_cache_}, tracker{tracker_}, blit_helper{instance, scheduler},
       tile_manager{instance, scheduler, buffer_cache.GetUtilityBuffer(MemoryUsage::Stream)} {
     // Create basic null image at fixed image ID.
     const auto null_id = GetNullImage(vk::Format::eR8G8B8A8Unorm);
@@ -51,6 +53,9 @@ TextureCache::TextureCache(const Vulkan::Instance& instance_, Vulkan::Scheduler&
         std::max<u64>(std::min(device_local_memory - min_vacancy_critical, min_spacing_critical),
                       DEFAULT_CRITICAL_GC_MEMORY));
     trigger_gc_memory = static_cast<u64>((device_local_memory - mem_threshold) / 2);
+
+    downloaded_images_thread =
+        std::jthread([&](const std::stop_token& token) { DownloadedImagesThread(token); });
 }
 
 TextureCache::~TextureCache() = default;
@@ -121,10 +126,34 @@ void TextureCache::DownloadImageMemory(ImageId image_id) {
     image.Transit(vk::ImageLayout::eTransferSrcOptimal, vk::AccessFlagBits2::eTransferRead, {});
     cmdbuf.copyImageToBuffer(image.image, vk::ImageLayout::eTransferSrcOptimal,
                              download_buffer.Handle(), image_download);
-    scheduler.DeferOperation([device_addr = image.info.guest_address, download, download_size] {
-        auto* memory = Core::Memory::Instance();
-        memory->TryWriteBacking(std::bit_cast<u8*>(device_addr), download, download_size);
-    });
+
+    {
+        std::unique_lock lock(downloaded_images_mutex);
+        downloaded_images_queue.emplace(scheduler.CurrentTick(), image.info.guest_address, download,
+                                        download_size);
+        downloaded_images_cv.notify_one();
+    }
+}
+
+void TextureCache::DownloadedImagesThread(const std::stop_token& token) {
+    auto* memory = Core::Memory::Instance();
+    while (!token.stop_requested()) {
+        DownloadedImage image;
+        {
+            std::unique_lock lock{downloaded_images_mutex};
+            Common::CondvarWait(downloaded_images_cv, lock, token,
+                                [this] { return !downloaded_images_queue.empty(); });
+            if (token.stop_requested()) {
+                break;
+            }
+            image = downloaded_images_queue.front();
+            downloaded_images_queue.pop();
+        }
+
+        scheduler.GetMasterSemaphore()->Wait(image.tick);
+        memory->TryWriteBacking(std::bit_cast<u8*>(image.device_addr), image.download,
+                                image.download_size);
+    }
 }
 
 void TextureCache::MarkAsMaybeDirty(ImageId image_id, Image& image) {

src/video_core/texture_cache/texture_cache.h

@@ -17,6 +17,10 @@
 #include "video_core/texture_cache/sampler.h"
 #include "video_core/texture_cache/tile_manager.h"
 
+namespace AmdGpu {
+struct Liverpool;
+}
+
 namespace VideoCore {
 
 class BufferCache;
@@ -85,7 +89,7 @@ public:
 
 public:
     TextureCache(const Vulkan::Instance& instance, Vulkan::Scheduler& scheduler,
-                 BufferCache& buffer_cache, PageManager& tracker);
+                 AmdGpu::Liverpool* liverpool, BufferCache& buffer_cache, PageManager& tracker);
     ~TextureCache();
 
     TileManager& GetTileManager() noexcept {
@@ -272,6 +276,9 @@ private:
     /// Copies image memory back to CPU.
     void DownloadImageMemory(ImageId image_id);
 
+    /// Thread function for copying downloaded images out to CPU memory.
+    void DownloadedImagesThread(const std::stop_token& token);
+
     /// Create an image from the given parameters
     [[nodiscard]] ImageId InsertImage(const ImageInfo& info, VAddr cpu_addr);
 
@@ -308,6 +315,7 @@ private:
 private:
     const Vulkan::Instance& instance;
     Vulkan::Scheduler& scheduler;
+    AmdGpu::Liverpool* liverpool;
     BufferCache& buffer_cache;
     PageManager& tracker;
     BlitHelper blit_helper;
@@ -326,6 +334,17 @@ private:
     PageTable page_table;
     std::mutex mutex;
 
+    struct DownloadedImage {
+        u64 tick;
+        VAddr device_addr;
+        void* download;
+        size_t download_size;
+    };
+    std::queue<DownloadedImage> downloaded_images_queue;
+    std::mutex downloaded_images_mutex;
+    std::condition_variable_any downloaded_images_cv;
+    std::jthread downloaded_images_thread;
+
     struct MetaDataInfo {
         enum class Type {
             CMask,