[vk, qcom] Samplers Budget Management

src/video_core/renderer_vulkan/vk_texture_cache.cpp

@@ -1516,6 +1516,10 @@ bool TextureCacheRuntime::CanReportMemoryUsage() const {
     return device.CanReportMemoryUsage();
 }
 
+std::optional<size_t> TextureCacheRuntime::GetSamplerHeapBudget() const {
+    return device.GetSamplerHeapBudget();
+}
+
 void TextureCacheRuntime::TickFrame() {}
 
 Image::Image(TextureCacheRuntime& runtime_, const ImageInfo& info_, GPUVAddr gpu_addr_,

src/video_core/renderer_vulkan/vk_texture_cache.h

@@ -65,6 +65,8 @@ public:
 
     bool CanReportMemoryUsage() const;
 
+    std::optional<size_t> GetSamplerHeapBudget() const;
+
     void BlitImage(Framebuffer* dst_framebuffer, ImageView& dst, ImageView& src,
                    const Region2D& dst_region, const Region2D& src_region,
                    Tegra::Engines::Fermi2D::Filter filter,

src/video_core/texture_cache/texture_cache.h

@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <limits>
+#include <optional>
 #include <unordered_set>
 #include <boost/container/small_vector.hpp>
 
@@ -1736,11 +1738,89 @@ SamplerId TextureCache<P>::FindSampler(const TSCEntry& config) {
     }
     const auto [pair, is_new] = channel_state->samplers.try_emplace(config);
     if (is_new) {
+        EnforceSamplerBudget();
         pair->second = slot_samplers.insert(runtime, config);
     }
     return pair->second;
 }
 
+template <class P>
+std::optional<size_t> TextureCache<P>::QuerySamplerBudget() const {
+    if constexpr (requires { runtime.GetSamplerHeapBudget(); }) {
+        return runtime.GetSamplerHeapBudget();
+    } else {
+        return std::nullopt;
+    }
+}
+
+template <class P>
+void TextureCache<P>::EnforceSamplerBudget() {
+    const auto budget = QuerySamplerBudget();
+    if (!budget) {
+        return;
+    }
+    if (slot_samplers.size() < *budget) {
+        return;
+    }
+    if (!channel_state) {
+        return;
+    }
+    if (last_sampler_gc_frame == frame_tick) {
+        return;
+    }
+    last_sampler_gc_frame = frame_tick;
+    TrimInactiveSamplers(*budget);
+}
+
+template <class P>
+void TextureCache<P>::TrimInactiveSamplers(size_t budget) {
+    if (channel_state->samplers.empty()) {
+        return;
+    }
+    static constexpr size_t SAMPLER_GC_SLACK = 1024;
+    auto mark_active = [](auto& set, SamplerId id) {
+        if (!id || id == CORRUPT_ID || id == NULL_SAMPLER_ID) {
+            return;
+        }
+        set.insert(id);
+    };
+    std::unordered_set<SamplerId> active;
+    active.reserve(channel_state->graphics_sampler_ids.size() +
+                   channel_state->compute_sampler_ids.size());
+    for (const SamplerId id : channel_state->graphics_sampler_ids) {
+        mark_active(active, id);
+    }
+    for (const SamplerId id : channel_state->compute_sampler_ids) {
+        mark_active(active, id);
+    }
+
+    size_t removed = 0;
+    auto& sampler_map = channel_state->samplers;
+    for (auto it = sampler_map.begin(); it != sampler_map.end();) {
+        const SamplerId sampler_id = it->second;
+        if (!sampler_id || sampler_id == CORRUPT_ID) {
+            it = sampler_map.erase(it);
+            continue;
+        }
+        if (active.find(sampler_id) != active.end()) {
+            ++it;
+            continue;
+        }
+        slot_samplers.erase(sampler_id);
+        it = sampler_map.erase(it);
+        ++removed;
+        if (slot_samplers.size() + SAMPLER_GC_SLACK <= budget) {
+            break;
+        }
+    }
+
+    if (removed != 0) {
+        LOG_WARNING(HW_GPU,
+                    "Sampler cache exceeded {} entries on this driver; reclaimed {} inactive samplers",
+                    budget, removed);
+    }
+}
+
 template <class P>
 ImageViewId TextureCache<P>::FindColorBuffer(size_t index) {
     const auto& regs = maxwell3d->regs;

src/video_core/texture_cache/texture_cache_base.h

@@ -429,6 +429,9 @@ private:
 
     void QueueAsyncDecode(Image& image, ImageId image_id);
     void TickAsyncDecode();
+    void EnforceSamplerBudget();
+    void TrimInactiveSamplers(size_t budget);
+    std::optional<size_t> QuerySamplerBudget() const;
 
     Runtime& runtime;
 
@@ -500,6 +503,7 @@ private:
 
     u64 modification_tick = 0;
     u64 frame_tick = 0;
+    u64 last_sampler_gc_frame = (std::numeric_limits<u64>::max)();
 
     Common::ThreadWorker texture_decode_worker{1, "TextureDecoder"};
     std::vector<std::unique_ptr<AsyncDecodeContext>> async_decodes;

src/video_core/vulkan_common/vulkan_device.cpp

@@ -583,6 +583,17 @@ Device::Device(VkInstance instance_, vk::PhysicalDevice physical_, VkSurfaceKHR
             version == VK_MAKE_API_VERSION(0, 512, 800, 51)) {
             has_broken_parallel_compiling = true;
         }
+        const size_t sampler_limit = properties.properties.limits.maxSamplerAllocationCount;
+        if (sampler_limit > 0) {
+            constexpr size_t MIN_SAMPLER_BUDGET = 1024U;
+            const size_t derived_budget =
+                (std::max)(MIN_SAMPLER_BUDGET, sampler_limit / 4U);
+            sampler_heap_budget = derived_budget;
+            LOG_WARNING(Render_Vulkan,
+                        "Qualcomm driver reports max {} samplers; clamping cache to {} (25%) to "
+                        "avoid heap exhaustion",
+                        sampler_limit, sampler_heap_budget);
+        }
     }
 
     if (extensions.sampler_filter_minmax && is_amd) {
@@ -1516,6 +1527,13 @@ void Device::SetupFamilies(VkSurfaceKHR surface) {
     }
 }
 
+std::optional<size_t> Device::GetSamplerHeapBudget() const {
+    if (sampler_heap_budget == 0) {
+        return std::nullopt;
+    }
+    return sampler_heap_budget;
+}
+
 u64 Device::GetDeviceMemoryUsage() const {
     VkPhysicalDeviceMemoryBudgetPropertiesEXT budget;
     budget.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_BUDGET_PROPERTIES_EXT;

src/video_core/vulkan_common/vulkan_device.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <optional>
 #include <set>
 #include <span>
 #include <string>
@@ -759,6 +760,8 @@ public:
         return has_broken_parallel_compiling;
     }
 
+    std::optional<size_t> GetSamplerHeapBudget() const;
+
     /// Returns the vendor name reported from Vulkan.
     std::string_view GetVendorName() const {
         return properties.driver.driverName;
@@ -1055,6 +1058,7 @@ private:
     bool dynamic_state3_alpha_to_coverage{};
     bool dynamic_state3_alpha_to_one{};
     bool supports_conditional_barriers{};      ///< Allows barriers in conditional control flow.
+    size_t sampler_heap_budget{};              ///< Sampler budget for buggy drivers (0 = unlimited).
     u64 device_access_memory{};                ///< Total size of device local memory in bytes.
     u32 sets_per_pool{};                       ///< Sets per Description Pool
     NvidiaArchitecture nvidia_arch{NvidiaArchitecture::Arch_AmpereOrNewer};