Ephedrine QoS: an antidote to slow, congested, bufferless NoCs

Area of Science:

• Computer Engineering
• Network Architecture
• High-Performance Computing

Background:

• Datacenters host diverse applications, leading to resource contention, particularly on networks-on-chip (NoCs).
• Bufferless NoCs offer area and power benefits but struggle with Quality-of-Service (QoS) for latency-critical applications.
• Existing bufferless NoC designs lack robust mechanisms for guaranteeing performance to high-priority services.

Purpose of the Study:

• To propose QBLESS, a QoS-aware bufferless NoC scheme tailored for datacenter environments.
• To address the performance degradation of high-priority applications caused by resource contention in bufferless NoCs.
• To improve overall system throughput while ensuring performance guarantees for critical services.

Main Methods:

• Developed QBLESS, comprising a routing mechanism (QBLESS-R) and a congestion-control mechanism (QBLESS-CC).
• QBLESS-R is designed to minimize flit deflection for high-priority traffic.
• QBLESS-CC aims to guarantee performance for high-priority applications and enhance system throughput.
• Utilized trace-driven simulation on a 64-core system to evaluate performance.

Main Results:

• QBLESS demonstrated an average performance improvement of 33.2% for high-priority applications compared to the BLESS design.
• Achieved an average reduction of 42.8% in network hops for high-priority applications.
• Showcased enhanced overall system throughput due to effective congestion management.

Conclusions:

• QBLESS effectively provides QoS guarantees in bufferless NoCs for datacenters.
• The proposed scheme significantly enhances the performance of latency-critical applications.
• QBLESS represents a promising advancement for bufferless NoC design in demanding datacenter workloads.