Intel® Ethernet 800 Series Application Device Queues (ADQ)

Software Developer's Guide

ID Date Version Classification
626536 04/03/2023 Public
Document Table of Contents
Document Table of Contents
Legal and Disclaimers Revision History Introduction Selecting Applications for ADQ Acceleration Adapting Applications to Take Advantage of ADQ Resources SO_REUSEPORT Patch - NGINX
Legal and Disclaimers
Revision History
Introduction
Introduction Application Device Queues (ADQ) Technology
Application Device Queues (ADQ) Technology
Application Device Queues (ADQ) Technology Option 1: Application Dependent Polling (ADQ1.0) Option 2: Application Independent Polling Method (ADQ2.0) Comparison of Polling Methods
Option 1: Application Dependent Polling (ADQ1.0)
Option 2: Application Independent Polling Method (ADQ2.0)
Comparison of Polling Methods
Selecting Applications for ADQ Acceleration
Adapting Applications to Take Advantage of ADQ
Adapting Applications to Take Advantage of ADQ SO_INCOMING_NAPI_ID Approach for Applications Written in C Programming Language SO_ATTACH_REUSEPORT_CBPF Approach SO_INCOMING_NAPI_ID Approach for Java-Based Applications
SO_INCOMING_NAPI_ID Approach for Applications Written in C Programming Language
SO_INCOMING_NAPI_ID Approach for Applications Written in C Programming Language Example Application: Memcached Design and Implementation
Example Application: Memcached Design and Implementation
Example Application: Memcached Design and Implementation Default Design Change Necessary for ADQ Enablement
Default Design
Change Necessary for ADQ Enablement
SO_ATTACH_REUSEPORT_CBPF Approach
SO_ATTACH_REUSEPORT_CBPF Approach Example Application: NGINX Design and Implementation
Example Application: NGINX Design and Implementation
Example Application: NGINX Design and Implementation Default Design Change Necessary for ADQ Enablement
Default Design
Change Necessary for ADQ Enablement
SO_INCOMING_NAPI_ID Approach for Java-Based Applications
Resources
SO_REUSEPORT Patch - NGINX
SO_REUSEPORT Patch - NGINX
SO_REUSEPORT Patch - NGINX

Comparison of Polling Methods

The application dependent polling method is supported in both ADQ1.0 and ADQ2.0, whereas the application independent polling method is supported only in ADQ2.0.

The following table compares the ADQ1.0 and 2.0 polling methods.

Application Dependent, ADQ1.0 and 2.0 Application Independent, ADQ2.0 only
  • Not feasible in all environments, requires application changes
  • Less configurable - global busy poll timeout
  • May have higher performance in certain cases
  • Kernel requirement:

    Epoll Busy Poll enhancement in 4.12+

  • Feasible in all environments without application changes
  • Resource/CPU utilization more tunable with per queue group poller timeout and number of polling threads
  • Kernel requirement:

    Kthread-based independent poller: 5.12+

    Ksoftirqd-based independent poller: 5.6

In ADQ1.0, busy polling is initiated by system calls made by the application and requires an application change. It operates in the context of an application.

In ADQ2.0, busy polling is initiated through interrupts and eliminates application changes. It runs in the NAPI kernel thread context.

The following figure depicts the difference between application dependent and independent polling methods in terms of busy polling.

Selecting Applications for ADQ Acceleration