Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2504.19058 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Table of Contents:
- We present Laminar, the first TCP stack that delivers ASIC-class performance and energy efficiency on programmable Reconfigurable Match-Action Table (RMT) pipelines, providing flexibility while retaining standard TCP semantics and POSIX socket compatibility. The key challenge to Laminar is reconciling TCP's complex dependent state updates with RMT's unidirectional, lock-step execution model. To overcome this challenge, Laminar introduces three novel techniques: optimistic concurrency (speculative updates validated downstream), pseudo-segment injection (circular dependency resolution without stalls), and bump-in-the-wire processing (single-pass segment handling). Together, these enable TCP processing, including retransmission, reassembly, flow, and congestion control, as a pipeline of simple match-action operations. Our Intel Tofino 2 prototype demonstrates Laminar's scalability to terabit speeds, flexibility, and robustness to network dynamics. Laminar matches RDMA performance and efficiency for both RPC and streaming workloads (including NVMe-oF with SPDK), while maintaining TCP/POSIX compatibility. Laminar saves up to 16 host CPU cores versus state-of-the-art kernel-bypass TCP, while achieving 5$\times$ lower 99.99p tail latency and 2$\times$ better throughput-per-watt for key-value stores. At scale, Laminar drives nearly $1$ Bpps at 20 $μ$s RPC tail latency. Unlike fixed-function offloads, Laminar supports transport evolution through in-data-path extensions (selective ACKs, congestion control variants, application co-design for shared logs). Finally, Laminar generalizes to FPGA SmartNICs, outperforming ToNIC's monolithic design by $3\times$ under equal timing.