Boyang Yan

LogNIC: A High-Level Performance Model for SmartNICs

2 min read

Jiaxin Lin

The paper “LogNIC: A High-Level Performance Model for SmartNICs” proposes a packet-centric analytical model to help developers reason about the performance of SmartNIC-offloaded applications without deep hardware knowledge. Here’s a summary and information about the SmartNICs it uses:

*Problem

SmartNICs (Smart Network Interface Cards) are widely used in modern data centers for offloading packet processing tasks from CPUs. However, developing optimized SmartNIC applications is complex, due to hardware heterogeneity, overlapping computation/I/O, and traffic-dependent performance.

*Solution

The authors introduce LogNIC, a high-level performance model for SmartNICs that abstracts hardware details and models performance based on packet traversal through execution graphs comprising compute engines, memory hierarchies, and interconnects.

Key Features of LogNIC:

  • Models latency and throughput using a directed acyclic graph (DAG) abstraction of SmartNIC execution.
  • Considers interleaved traffic, multiple tenants, and accelerator variability.
  • Offers both estimation mode (predicts performance) and optimizer mode (suggests configurations to meet performance goals).
  • Inspired by and extends architectural models like Roofline, LogCA, and Accelerometer.

Evaluation Results:

  • Validated using real SmartNICs, LogNIC accurately estimates performance with <1% error in some scenarios.
  • It helps optimize parallelism and placement decisions, improving throughput by up to 36.4% and latency by up to 22.8%.
  • Can also guide early-stage hardware design decisions.

Which SmartNICs Are Used?

The authors evaluated LogNIC on the following hardware:

  1. Marvell LiquidIO-II CN2360
    • 25GbE
    • 16×1.5GHz cnMIPS cores
    • Accelerator-rich (e.g., MD5, CRC, ZIP, HFA)
    • Bump-in-the-wire SmartNIC
  2. Mellanox BlueField-2 DPU
    • 100GbE
    • 8×2.5GHz ARM A72 cores
    • General-purpose SmartNIC with programmable cores
    • Off-path SmartNIC
  3. Broadcom Stingray PS1100R
    • 100GbE
    • 8×3.0GHz ARM A72 cores, 8GB DDR4
    • Supports NVMe-oF workloads
    • Off-path SmartNIC
  4. PANIC (Academic Prototype)
    • Used for design space exploration
    • Not a commercial product, but demonstrates configurability in research settings

Graph View