Route C: replace PyTorch's cudaMalloc/cudaFree with CCCL CUB's CachingDeviceAllocator via LD_PRELOAD. Eliminates driver-level allocation overhead by reusing freed GPU memory from a bin-based cache. Based on cccl_upstream/cub/cub/util_allocator.cuh (901 lines). Self-contained .so with no CCCL header dependencies at compile time. Files: - cccl_preload_allocator.cu: the allocator (405 lines) - build_cccl_preload_allocator.sh: build script (corex clang++ or g++ fallback) - test_cccl_preload.sh: smoke test suite for BI-V100 - patch_ops.sh: build during docker build - computility-run.yaml: LD_PRELOAD env var for runtime Config via env: CCCL_ALLOC_BIN_GROWTH=8, MIN_BIN=3, MAX_BIN=13, MAX_CACHED_MB=4096 Test on real machine: cd qwen3_6_scripts && bash test_cccl_preload.sh
122 lines
3.4 KiB
Bash
Executable File
122 lines
3.4 KiB
Bash
Executable File
#!/usr/bin/env bash
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# Quick test for CCCL preload allocator on BI-V100
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# Usage: cd /home/dylan/project_6/qwen3_6_scripts && bash test_cccl_preload.sh
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set -eo pipefail
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SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
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SO="${SCRIPT_DIR}/cccl_preload_allocator.so"
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echo "=== Step 1: Build ==="
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bash "${SCRIPT_DIR}/build_cccl_preload_allocator.sh" "${SCRIPT_DIR}"
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echo ""
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if [[ ! -f "$SO" ]]; then
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echo "BUILD FAILED: $SO not found"
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exit 1
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fi
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echo "=== Step 2: Basic smoke test (torch.zeros on GPU) ==="
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echo "Without preload:"
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python3 -c "
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import time, torch
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t0=time.time()
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for i in range(100):
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x=torch.zeros(1024*1024, device='cuda')
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del x
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torch.cuda.synchronize()
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print(f'100 alloc+free cycles: {time.time()-t0:.3f}s')
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"
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echo ""
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echo "With CCCL preload:"
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CCCL_ALLOC_DEBUG=0 LD_PRELOAD="$SO" python3 -c "
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import time, torch
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t0=time.time()
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for i in range(100):
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x=torch.zeros(1024*1024, device='cuda')
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del x
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torch.cuda.synchronize()
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print(f'100 alloc+free cycles: {time.time()-t0:.3f}s')
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" 2>&1
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echo ""
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echo "=== Step 3: Varied sizes (simulating model inference allocations) ==="
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CCCL_ALLOC_DEBUG=0 LD_PRELOAD="$SO" python3 -c "
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import time, torch
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# Simulate inference: repeated allocs of same sizes (should hit cache)
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sizes = [512, 4096, 32768, 262144, 1048576, 4194304, 16777216] # 512B to 16MB
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tensors = []
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print('First pass (cold cache):')
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t0 = time.time()
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for s in sizes:
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x = torch.empty(s // 2, dtype=torch.float16, device='cuda') # s bytes
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tensors.append(x)
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t1 = time.time()
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print(f' {len(sizes)} allocs: {(t1-t0)*1000:.1f}ms')
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print('Free all:')
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del tensors
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torch.cuda.synchronize()
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t2 = time.time()
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print(f' {len(sizes)} frees: {(t2-t1)*1000:.1f}ms')
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print('Second pass (warm cache - should be faster):')
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tensors2 = []
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for s in sizes:
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x = torch.empty(s // 2, dtype=torch.float16, device='cuda')
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tensors2.append(x)
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t3 = time.time()
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print(f' {len(sizes)} allocs: {(t3-t2)*1000:.1f}ms')
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print('Third pass (reuse same sizes 100x):')
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for _ in range(100):
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for s in sizes:
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x = torch.empty(s // 2, dtype=torch.float16, device='cuda')
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del x
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t4 = time.time()
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print(f' 700 alloc+free: {(t4-t3)*1000:.1f}ms ({(t4-t3)/700*1000000:.0f}μs/op)')
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" 2>&1
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echo ""
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echo "=== Step 4: Large allocation test (model weights sized) ==="
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CCCL_ALLOC_DEBUG=0 LD_PRELOAD="$SO" python3 -c "
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import torch
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# Simulate KV cache blocks (typical: 256KB-2MB each)
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blocks = []
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for i in range(100):
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b = torch.empty(256*1024 // 2, dtype=torch.float16, device='cuda')
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blocks.append(b)
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print(f'Allocated 100 x 256KB blocks = {100*256/1024:.0f}MB')
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del blocks
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torch.cuda.synchronize()
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print('Freed all blocks')
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# Reallocate (should hit cache)
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blocks2 = []
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for i in range(100):
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b = torch.empty(256*1024 // 2, dtype=torch.float16, device='cuda')
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blocks2.append(b)
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print('Re-allocated 100 blocks (from cache)')
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print('OK: large allocation test passed')
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" 2>&1
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echo ""
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echo "=== Step 5: Stats output ==="
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CCCL_ALLOC_DEBUG=0 LD_PRELOAD="$SO" python3 -c "
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import torch
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for _ in range(50):
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x = torch.zeros(1024*1024, device='cuda')
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del x
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# Stats print on process exit
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" 2>&1
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echo ""
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echo "=== DONE ==="
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echo "If all tests passed, add to your launch command:"
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echo " LD_PRELOAD=$SO python3 -m vllm.entrypoints.openai.api_server ..."
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echo ""
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echo "Or set in computility-run.yaml env:"
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echo " - name: LD_PRELOAD"
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echo " value: /workspace/qwen3_6_scripts/cccl_preload_allocator.so"
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