RDMA READ (batch_transfer_sync_read) fails on GPU memory because
batch_register_memory only sets IBV_ACCESS_REMOTE_WRITE.
New approach: D sends /push_blocks to C's bootstrap with token_ids
+ D's GPU addresses. C's bootstrap:
1. Looks up matching blocks in synced hash table (640/640 verified)
2. Uses C's TransferEngine.batch_transfer_sync_write to PUSH blocks
directly into D's GPU memory
3. Returns match count + push status
C's scheduler is still NOT involved (0 GPU compute on C).
The push uses C's worker thread + existing RDMA WRITE path (proven reliable).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Gahow Wang
e3a1d70cf2