FreeRTOS SMP Task Switch Example

Table of Contents

• Introduction
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This example shows usage of direct FreeRTOS APIs, i.e not via the DPL APIs. It shows usage of task APIs, task notification APIs, semaphore and delay APIs. It also shows how to signal to FreeRTOS task from ISRs.

The example does the below

• Creates two semaphores
• Creates two tasks, ping and pong
• Run tasks with core affinity
• Ping and pong tasks signal each other using semaphores and task notifications
• A HW ISR is also created and ping task is signaled from the ISR
• Task delay API usage is shown

Supported Combinations

Attention

A53 FREERTOS SMP support is experimental and is NOT supported by TI.

Parameter	Value
CPU + OS	a53ss0-0 freertos-smp
Toolchain	arm.gnu.aarch64-none
Board	am64x-evm
Example folder	examples/kernel/freertos/smp_task_switch

Steps to Run the Example

Note

Create a sync group for cores when running an SMP example in CCS

• When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see Using SDK with CCS Projects).
• When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)
• Launch a CCS debug session and run the executable, see CCS Launch, Load and Run

See Also

FreeRTOS

Sample Output

Shown below is a sample output when the application is run,

[FreeRTOS] ping task ... start !!!
 
execution time for task switches = 32937660 us
number of task switches = 2000000
time per task switch (semaphore give/take) = 16468 ns
 
execution time for task switches = 17862161 us
number of task switches = 2000000
time per task switch (direct-to-task notification give/take) = 8931 ns
 
execution time for task - ISR - task - task switches = 19287679 us
number of ISRs = 2000000
time per task - ISR - task switch (semaphore give/take) = 9643 ns
 
[FreeRTOS] ping task ... done !!!
 
All tests have passed!!