Metal: track types of buffers (#7796)

google · May 6, 2024 · dd3b19c · dd3b19c
1 parent b7eb12b
commit dd3b19c
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Showing 4 changed files with 61 additions and 14 deletions.
diff --git a/filament/backend/src/metal/MetalBuffer.h b/filament/backend/src/metal/MetalBuffer.h
@@ -33,15 +33,42 @@ namespace filament::backend {
 
 class TrackedMetalBuffer {
 public:
+
+    enum class Type {
+        NONE = 0,
+        GENERIC = 1,
+        RING = 2,
+        STAGING = 3,
+    };
+    static constexpr size_t TypeCount = 3;
+
+    static constexpr auto toIndex(Type t) {
+        assert_invariant(t != Type::NONE);
+        switch (t) {
+            case Type::NONE:
+            case Type::GENERIC:
+                return 0;
+            case Type::RING:
+                return 1;
+            case Type::STAGING:
+                return 2;
+        }
+    }
+
     TrackedMetalBuffer() noexcept : mBuffer(nil) {}
-    TrackedMetalBuffer(id<MTLBuffer> buffer) noexcept : mBuffer(buffer) {
+    TrackedMetalBuffer(nullptr_t) noexcept : mBuffer(nil) {}
+    TrackedMetalBuffer(id<MTLBuffer> buffer, Type type) : mBuffer(buffer), mType(type) {
+        assert_invariant(type != Type::NONE);
         if (buffer) {
-            aliveBuffers++;
+            aliveBuffers[toIndex(type)]++;
+            mType = type;
         }
     }
+
     ~TrackedMetalBuffer() {
         if (mBuffer) {
-            aliveBuffers--;
+            assert_invariant(mType != Type::NONE);
+            aliveBuffers[toIndex(mType)]--;
         }
     }
 
@@ -57,18 +84,29 @@ class TrackedMetalBuffer {
     id<MTLBuffer> get() const noexcept { return mBuffer; }
     operator bool() const noexcept { return bool(mBuffer); }
 
-    static uint64_t getAliveBuffers() { return aliveBuffers; }
+    static uint64_t getAliveBuffers() {
+        uint64_t sum = 0;
+        for (const auto& v : aliveBuffers) {
+            sum += v;
+        }
+        return sum;
+    }
+
+    static uint64_t getAliveBuffers(Type type) {
+        assert_invariant(type != Type::NONE);
+        return aliveBuffers[toIndex(type)];
+    }
 
 private:
     void swap(TrackedMetalBuffer& other) noexcept {
-        id<MTLBuffer> temp = mBuffer;
-        mBuffer = other.mBuffer;
-        other.mBuffer = temp;
+        std::swap(mBuffer, other.mBuffer);
+        std::swap(mType, other.mType);
     }
 
     id<MTLBuffer> mBuffer;
+    Type mType = Type::NONE;
 
-    static std::atomic<uint64_t> aliveBuffers;
+    static std::array<uint64_t, TypeCount> aliveBuffers;
 };
 
 class MetalBuffer {
@@ -171,7 +209,8 @@ class MetalRingBuffer {
           mBufferOptions(options),
           mSlotSizeBytes(computeSlotSize(layout)),
           mSlotCount(slotCount) {
-        mBuffer = [device newBufferWithLength:mSlotSizeBytes * mSlotCount options:mBufferOptions];
+        mBuffer = { [device newBufferWithLength:mSlotSizeBytes * mSlotCount options:mBufferOptions],
+            TrackedMetalBuffer::Type::RING };
         assert_invariant(mBuffer);
     }
 
@@ -189,9 +228,10 @@ class MetalRingBuffer {
             // If we already have an aux buffer, it will get freed here, unless it has been retained
             // by a MTLCommandBuffer. In that case, it will be freed when the command buffer
             // finishes executing.
-            mAuxBuffer = [mDevice newBufferWithLength:mSlotSizeBytes options:mBufferOptions];
+            mAuxBuffer = { [mDevice newBufferWithLength:mSlotSizeBytes options:mBufferOptions],
+                TrackedMetalBuffer::Type::RING };
             assert_invariant(mAuxBuffer);
-            return {mAuxBuffer.get(), 0};
+            return { mAuxBuffer.get(), 0 };
         }
         mCurrentSlot = (mCurrentSlot + 1) % mSlotCount;
         mOccupiedSlots->fetch_add(1, std::memory_order_relaxed);

diff --git a/filament/backend/src/metal/MetalBuffer.mm b/filament/backend/src/metal/MetalBuffer.mm
@@ -22,7 +22,7 @@
 namespace filament {
 namespace backend {
 
-std::atomic<uint64_t> TrackedMetalBuffer::aliveBuffers = 0;
+std::array<uint64_t, TrackedMetalBuffer::TypeCount> TrackedMetalBuffer::aliveBuffers = { 0 };
 
 MetalBuffer::MetalBuffer(MetalContext& context, BufferObjectBinding bindingType, BufferUsage usage,
         size_t size, bool forceGpuBuffer) : mBufferSize(size), mContext(context) {
@@ -37,7 +37,8 @@
     }
 
     // Otherwise, we allocate a private GPU buffer.
-    mBuffer = [context.device newBufferWithLength:size options:MTLResourceStorageModePrivate];
+    mBuffer = { [context.device newBufferWithLength:size options:MTLResourceStorageModePrivate],
+        TrackedMetalBuffer::Type::GENERIC };
     ASSERT_POSTCONDITION(mBuffer, "Could not allocate Metal buffer of size %zu.", size);
 }
 

diff --git a/filament/backend/src/metal/MetalBufferPool.mm b/filament/backend/src/metal/MetalBufferPool.mm
@@ -46,7 +46,7 @@
                                                         options:MTLResourceStorageModeShared];
     ASSERT_POSTCONDITION(buffer, "Could not allocate Metal staging buffer of size %zu.", numBytes);
     MetalBufferPoolEntry* stage = new MetalBufferPoolEntry {
-        .buffer = buffer,
+        .buffer = { buffer, TrackedMetalBuffer::Type::STAGING },
         .capacity = numBytes,
         .lastAccessed = mCurrentFrame,
         .referenceCount = 1

diff --git a/filament/backend/src/metal/MetalDriver.mm b/filament/backend/src/metal/MetalDriver.mm
@@ -219,6 +219,12 @@
 #endif
     if (mPlatform.hasDebugUpdateStatFunc()) {
         mPlatform.debugUpdateStat("filament.metal.alive_buffers", TrackedMetalBuffer::getAliveBuffers());
+        mPlatform.debugUpdateStat("filament.metal.alive_buffers.generic",
+                TrackedMetalBuffer::getAliveBuffers(TrackedMetalBuffer::Type::GENERIC));
+        mPlatform.debugUpdateStat("filament.metal.alive_buffers.ring",
+                TrackedMetalBuffer::getAliveBuffers(TrackedMetalBuffer::Type::RING));
+        mPlatform.debugUpdateStat("filament.metal.alive_buffers.staging",
+                TrackedMetalBuffer::getAliveBuffers(TrackedMetalBuffer::Type::STAGING));
     }
 }