Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Real time embedded FreeRTOS mailing list 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem TCP & FAT Training


speedup freertos

Posted by mastupristi on March 1, 2017

Hi, I have an STM32F410 cortex M4 clocked @100MHz. I notify an high priority task from another, with lower priority, using xTaskNotifyGive()/ulTaskNotifyTake(). The firmware is compiled with arm-gcc: ~~~ ~$ arm-none-eabi-gcc --version arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 5.4.1 20160609 (release) [ARM/embedded-5-branch revision 237715] ~~~ and I already use -O3 optimization. Moving a pin I can measure time between notification and task wakeup. It is about 4us. Is it possible to speed up notification (I think also context switch)?

best regards Max

speedup freertos

Posted by heinbali01 on March 1, 2017

Hi Max

There are many factors influencing this delay between vTaskNotifyGiveFromISR() and ulTaskNotifyTake(). Compiler optimisation, for GCC, use -Os or -O3. I tend to like -Os ( optimise for size ) Once you're ready debugging, stop using configASSERT() and stop checking the for stack overflows. Make sure that the task that you are waking-up has the highest priority of all tasks that are runnable at that moment. Please let us hear

speedup freertos

Posted by hs2sf on March 1, 2017

I also tend to use -Os instead of -O3 with GCC. In addition I get pretty good results using link time optimization (LTO) ie. using -flto. At least it saves even more code space which usually also improves runtime performance.

speedup freertos

Posted by rtel on March 1, 2017

Stack overflow detection is the feature that takes the most time to execute.

As has already been said, turning off run time stats, asserts, tick hooks, etc. all help. The context switch itself is not the limiting factor.

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

Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2016 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd.. See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.

Latest News:

FreeRTOS V9.0.0 is now available for download.

Free TCP/IP and file system demos for the RTOS

Sponsored Links

⇓ Now With No Code Size Limit! ⇓
⇑ Free Download Without Registering ⇑

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Renesas Electronics Gold Alliance RTOS Partner.jpg

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers

Atmel RTOS partner supporting ARM Cortex-M3 and AVR32 microcontrollers

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

Xilinx Microblaze and Zynq partner

Silicon Labs low power RTOS partner

Altera RTOS partner for Nios II and Cortex-A9 SoC

Freescale Alliance RTOS Member supporting ARM and ColdFire microcontrollers

Infineon ARM Cortex-M microcontrollers

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

Cypress RTOS partner supporting ARM Cortex-M3

Fujitsu RTOS partner supporting ARM Cortex-M3 and FM3

Microsemi (previously Actel) RTOS partner supporting ARM Cortex-M3

Atollic Partner

IAR Partner

Keil ARM Partner

Embedded Artists