Preemptive config

Support Kernel
1

Hello,

I have recently started to use Manjaro on an old Cromebook with low performance and wonder what kind of preemptiveness is used by default in the manajro default kernel (in my case 6.1.1-1-MANJARO #1 SMP PREEMPT_DYNAMIC). Other distribution I have used have a low_latency kernel. I don’t find it in Manjaro, but I understand the PREEMPTIVE_DYNAMIC allows booting it with different settings and it should be possible to change it on the fly when running it.

My questions:

What is the default scheduling policy?

How do I change scheduling policy on the fly if I would like to test? /sys/kernel/debug/sched_preempt does not exist in my system.

Is the default Manjaro kernel with preempt=full the same as low-latency kernel in Ubuntu?

2

Are you sure?

LANG=C ls -al /sys/kernel/debug
will yield:
ls: cannot open directory '/sys/kernel/debug': Permission denied

sudo su -
and then
cat /sys/kernel/debug/sched/preempt
will yield:
none voluntary (full)

(root access is required)

I don’t know about the rest - re scheduling, the Arch wiki should be informative.

3

Thanks.
I was looking in /sys/kernel/debug/sched_preempt and it does not exist.
/sys/kernel/debug/sched/preempt do exist and has “none voluntary (full)”

4

indeed
it was too similar when I went looking for it
I forgot along the way what you actually said.
Sorry!

5

I found it :raised_hand: :wink:

CONFIG_PREEMPT_DYNAMIC=y