topic Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK in i.MX Processors

How to enable Preempt-RT function in Kernel 6.1.1 SDK

t2865k5 — Fri, 08 Sep 2023 07:37:19 GMT

Dear NXP ,

HW: imx8mplus

SW : kernel 6.1.1

repo init -u https://github.com/nxp-imx/imx-manifest -b imx-linux-langdale -m imx-6.1.1-1.0.1.xml

I want to enable Preempt-RT function on imx8mplus platform. I check kernel config as follows:

CONFIG_PREEMPT_BUILD=y
CONFIG_PREEMPT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_PREEMPTION=y

I can't find this CONFIG_PREEMPT_RT in kernel 6.1.1 SDK.

Do I need to add some patchs to the current SDK? (kernel 6.1.1)

Please tell me how to enable Preempt-RT function .

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

Zhiming_Liu — Tue, 12 Sep 2023 04:45:54 GMT

We recommand you use real-time-edge-software which has enabled Preempt-RT feature.

https://www.nxp.com/design/software/development-software/real-time-edge-software:REALTIME-EDGE-SOFTWARE

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

t2865k5 — Tue, 12 Sep 2023 09:18:09 GMT

Dear Zhiming ,

I can't use the real-time-edge 2.6 SDK because there is a big difference between the real-time-edge 2.6 and kernel 6.1.1 (deconfig).

In kernel 6.1.1 deconfig :CONFIG_PREEMPT=y

Does it enable Preempt-RT function?
If the Preempt-RT function is not enabled, please provide related patches to me .

回复： How to enable Preempt-RT function in Kernel 6.1.1 SDK

t2865k5 — Mon, 18 Sep 2023 02:45:49 GMT

Dear Zhiming ,

Could you answer the following questions?

In kernel 6.1.1 deconfig :CONFIG_PREEMPT=y

(1) Does it enable Preempt-RT function?
(2) If the Preempt-RT function is not enabled, please provide related patches to me .

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

Zhiming_Liu — Mon, 18 Sep 2023 04:02:54 GMT

Hi @t2865k5

1.linux-imx can't support Preempt-RT function

2. If you need patches about Preempt-RT function, you can export them from RT kernel :

https://github.com/nxp-real-time-edge-sw/real-time-edge-linux

Best Regards

Zhiming

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

t2865k5 — Wed, 20 Sep 2023 02:12:48 GMT

Dear Zhiming ,

I have some questions as follows :

(1) For real-time-edge-linux image , I can modify as follows:

CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_PREEMPTION=y

Does it enable Preempt-RT function ?

(2) For kernel 6.1.1 image,

CONFIG_PREEMPT=y

what function does it have ?

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

Zhiming_Liu — Wed, 20 Sep 2023 04:08:07 GMT

The CONFIG_PREEMPT function is missing in kernel 6.1.x

You should use Preempt-RT patches from Linux Fundation for kernel 6.1.x

https://wiki.linuxfoundation.org/realtime/preempt_rt_versions

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

t2865k5 — Wed, 20 Sep 2023 09:52:08 GMT

Dear Zhiming ,

Could you answer my first question?

(1) For real-time-edge-linux image , I can modify as follows:

CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT_COUNT=y
CONFIG_PREEMPTION=y

Does it enable Preempt-RT function ?

Re: How to enable Preempt-RT function in Kernel 6.1.1 SDK

Zhiming_Liu — Fri, 22 Sep 2023 01:35:03 GMT

Hi @t2865k5

Yes, but for usage of these confg, please refer comments in Kconfig.preempt

https://github.com/nxp-real-time-edge-sw/real-time-edge-linux/blob/linux_5.10.y/kernel/Kconfig.preempt

Best Regards

Zhiming