Nordic Fundamentals - Lesson 7 Exercise 2 - no starving from thread1

[MarkusK]

Hello,

I tried the example from the exercise. I dint change anything which means I didnt activate timeslicing yet and I already get the output:

Hello, I am thread0
Hello, I am thread1
Hello, I am thread0
Hello, I am thread1
Hello, I am thread0

Doesnt fit to the explanation. thread1 should starve since thread0 is running first and does not yield or sleep. I tested it with nrf54l15dk and nrf52840dk. Both the same behaviour. Toolchain and SDK is v3.1.1.
Already with exersice 1 from this lesson there were a similar behaviour, but since there was no delay in the output, I thought it was a uart timing problem.

Activating the timeslicing I have the same behaviour:
Hello, I am thread0
Hello, I am thread1
Hello, I am thread0
Hello, I am thread1
Hello, I am thread0

After changing the priority thread1 is starving like expected:

#define THREAD0_PRIORITY 6

#define THREAD1_PRIORITY 7

Hello, I am thread0
Hello, I am thread0
Hello, I am thread0
Hello, I am thread0
Hello, I am thread0

[MarkusK]

I found it out by myself. It seems timeslicing is activated by default. I found this in the .config:

#

# Timer API Options

#

CONFIG_TIMESLICING=y

CONFIG_TIMESLICE_PRIORITY=0

So it looks like that there was a change in the default settings in the new zephyr toolchain. If so the explanation in the exercise is confusing.

[Benjamin]

Hi Markus,
Yes, it’s enabled by default, but the exercise explicitly disables it in prj.conf. Not sure where you might have deviated from the exercise steps. Could you share your build logs? I am curious about what happened here.

Best regards,
Benjamin

[MarkusK]

It wasnt disabled by default in the prj.conf since I downloaded the GIT repository around 4-5 weeks ago. Adding CONFIG_TIMESLICING=n in the prj.conf was added around 3 weeks ago. 
https://github.com/NordicDeveloperAcademy/ncs-fund

Regards
Markus

[Benjamin]

Hi,
That makes sense, I can see the change. I'll close the ticket, have a nice day!

Thanks,

Benjamin