vk_pipeline_cache: cap boot builds when no used list exists yet

Without vulkan_used.bin (the first boot with this change, or a session
that ended before saving it) every cached graphics pipeline was still
built at boot. A Linux tester's cache had grown to 47,951 pipelines over
many builds: ~21 GB of driver memory built before the game started,
filling RAM and swap. The list is only saved at exit or after two
minutes, so a boot that ran out of memory never saved one and the next
boot did the same.

Build at most 3,000 cached graphics pipelines at boot in that case and
the rest when first needed; the next session uses the saved list.
EDEN_NX2_PRELOAD_ALL_PIPELINES=1 still builds all of them.

1 files changed, 13 insertions, 2 deletions

diff --git a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
index 2eee5dbf45..1d0b3a07b6 100644
--- a/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
+++ b/src/video_core/renderer_vulkan/vk_pipeline_cache.cpp
@@ -591,6 +591,13 @@ std::unordered_map<u64, u8> LoadUsedPipelines(const std::filesystem::path& path)
     return used;
 }
 
+// Without a list of the pipelines recent sessions used (the first boot with this cache, or a session
+// that ended before saving it), this many cached graphics pipelines at most are built at boot and the
+// rest when first needed. A cache that grew over many builds held 48k pipelines, ~21 GB of driver
+// memory built before the game started; the list is only saved at exit or after two minutes, so a
+// boot that ran out of memory never saved one and the next boot did the same.
+constexpr size_t MaxPipelinesWithoutUsedList = 3000;
+
 // EDEN_NX2_PRELOAD_ALL_PIPELINES=1 builds every cached pipeline at boot, as before.
 bool PreloadAllPipelines() {
     static const bool all = [] {
@@ -706,6 +713,7 @@ void PipelineCache::LoadDiskResources(u64 title_id, std::stop_token stop_loading
     used_pipelines = LoadUsedPipelines(used_pipelines_filename);
     used_pipelines_saved = std::chrono::steady_clock::now();
     size_t skipped_pipelines = 0;
+    size_t queued_graphics = 0;
 
     if (use_vulkan_pipeline_cache) {
         vulkan_pipeline_cache_filename = base_dir / "vulkan_pipelines.bin";
@@ -776,10 +784,13 @@ void PipelineCache::LoadDiskResources(u64 title_id, std::stop_token stop_loading
 
         const u64 hash = key.Hash();
         disk_pipelines.insert(hash);
-        if (!PreloadAllPipelines() && !used_pipelines.empty() && !used_pipelines.contains(hash)) {
+        if (!PreloadAllPipelines() &&
+            (used_pipelines.empty() ? queued_graphics >= MaxPipelinesWithoutUsedList
+                                    : !used_pipelines.contains(hash))) {
             ++skipped_pipelines;
             return;
         }
+        ++queued_graphics;
 
         workers.QueueWork([this, key, envs_ = std::move(envs), &state, &callback]() mutable {
             ShaderPools pools;
@@ -807,7 +818,7 @@ void PipelineCache::LoadDiskResources(u64 title_id, std::stop_token stop_loading
     LOG_INFO(Render_Vulkan, "Total Pipeline Count: {}", state.total);
     if (skipped_pipelines != 0) {
         LOG_INFO(Render_Vulkan,
-                 "{} cached graphics pipelines no recent session used are built when first needed",
+                 "{} cached graphics pipelines are built when first needed",
                  skipped_pipelines);
     }