Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem


vTaskGetRunTimeStats: 1 task > 100% CPU?

Posted by Thomas Johansen on May 31, 2013

I'm using the vTaskGetRunTimeStats to get runtime information of the tasks.
But 1 task starts out with CPU usage to more than 100 % (A huge number ex: 152354223%)
The value is decreasing over time and ends up where it should be.

The task is straight forward, it waits on a queue with a timeout of 5 sec. The priority is just like the other task

Any idea what could cause this? Event if the task was badly written it should just ending up using 100 % !!


RE: vTaskGetRunTimeStats: 1 task > 100% CPU?

Posted by Richard on May 31, 2013
I actually noticed something like this myself - while giving a live demonstration of all times for it to happen. I'm not sure what caused it but suspect it will be either an initialisation timing problem (whereby the first reading is taken before the timer used for the stats is initialised properly), or some kind of calculation rounding or underflow problem. Please report back if you find the answer - and in the mean time please also add a "bug report" in the FreeRTOS SourceForge bug tracker to ensure the problem is investigated properly.


[ Back to the top ]    [ About FreeRTOS ]    [ Sitemap ]    [ ]

Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

Meet us at Embedded World. Hall 3A-525.

Hear from Richard Barry at Embedded World. Feb 28, 16:00, Hall 4-428.

Video: Watch James Gosling & Richard Barry at re:Invent, Las Vegas 2017.

FreeRTOS kernel V10.0.1 is available for immediate download. Now MIT licensed.

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

OpenRTOS and SafeRTOS