add cold start

include/shred.h

@@ -26,6 +26,7 @@
 #define CHUNK_SIZE_STEP_UP 1024 * 1024 * 4   // Increase step: 4MB (symmetric with step down)
 #define CHUNK_SIZE_STEP_DOWN 1024 * 1024 * 4 // Decrease step: 4MB (symmetric exploration)
 #define CHUNK_MEASURE_INTERVAL 64            // Measure performance every 64 chunks
+#define WARMUP_MEASUREMENTS 16               // Skip first 16 measurements (cache writes)
 
 // Multi-armed bandit exploration parameters
 #define EXPLORATION_EPSILON 0.10   // 10% exploration rate (epsilon-greedy)
@@ -67,6 +68,7 @@ private:
     size_t bestChunkSize;
     unsigned int chunkCounter;
     unsigned int totalChunkCounter; // Total chunks written (for periodic re-exploration)
+    unsigned int warmupCounter;     // Count warm-up measurements
     std::chrono::high_resolution_clock::time_point measurementStartTime;
     double bestThroughputMBps;
     double lastThroughputMBps;