AN 886: Intel® Agilex™ Device Design Guidelines

ID 683634
Date 8/26/2022
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

9.7.3. Using Symmetrical vs. Asymmetrical Multiprocessing (SMP vs. AMP) Modes

The Quad Core Arm* Cortex-A53 MPCore* in the Intel® Agilex™ HPS can support both Symmetrical Multi Processing (SMP) and Asymmetrical Multi-processing (AMP) operating modes.

In SMP mode, a single operating system instance controls all four cores. The SMP configuration is supported by a wide variety of operating system manufacturers and is the most common and straightforward configuration mode for multiprocessing.

Linux and commercially developed operating systems offer features that take full advantage of the CPU cores resources and use them in an efficient manner resulting in optimized performance and ease of use. For instance, SMP-enabled operating systems offer the option of setting processor affinity. This means that each task or thread can be assigned to run on a specific core. This feature allows you to better control the workload distribution for each Arm* Cortex-A53 core and making the system more responsive as an alternative to AMP.

GUIDELINE: Familiarize yourself with the performance and optimizations available in commercial operating systems to see if an SMP-enabled operating system or RTOS meets your performance and real-time requirements.

In the AMP configuration, up to four different operating systems could run on the four Cortex*-A53 cores, which allows more valid combinations. You could also combine AMP and SMP allowing you to have two cores running an SMP and the other two cores running an AMP.

Special Considerations

  • Use AMP only if you are familiar with the techniques to manage and schedule processes, handle inter-process communication, synchronize between events, and manage secure processes between the two instances of the operating systems.
  • OS providers do not generally offer support for using their operating system in an AMP mode, so a special support agreement is typically needed in this case.
  • If you use AMP, it is best to use the virtualization feature of the Cortex-A53 because the Cortex-A53 includes native hardware support for virtualization solving most of the AMP resource sharing issues.