Key changes:
- managed_alloc.cu: Add cudaMemPrefetchAsync to migrate pages to GPU
immediately (prevents OOM from system RAM pinning on EGM systems
where only ~102 GiB RAM remains). Add cudaMemAdviseSetAccessedBy
for CPU so reads go over C2C NVLink without page migration.
- vllm_managed_mem.py: Rewrite with idempotent patches, proper
MemorySnapshot.measure() override, and torch.cuda tracking stubs
for CUDAPluggableAllocator compatibility.
- sitecustomize.py: Auto-loaded by Python in ALL subprocesses
(including vLLM EngineCore). Applies allocator swap, torch patches,
MemorySnapshot override, and request_memory override before any
CUDA operations in spawned processes.
- Dockerfile: Install sitecustomize.py into Python dist-packages.
- README.md: Full rewrite with EGM problem statement, memory layout,
architecture diagram, and build pipeline documentation.
