[PlanetCCRMA] Akmod for the realtime kernel

[Fernando Lopez-Lezcano]

On 1/9/22 4:39 AM, Yoann LE BARS wrote:
> 
> Hello, everybody out there!
> 
> On 2022/01/09 at 12:44 am, Nils Tonnätt wrote:
>> If you can wait until 5.16 is released on Fedora, you should be able 
>> to just pass preempt=full as a boot parameter.
>> Dynamic preemption is in the kernel since some kernel versions, but it 
>> wasn't enabled in Fedora, because you
>> couldn't set it up in a way that satisfied the Fedora kernel 
>> maintainers. That changed in 5.16.
>> So I hope they remember to turn it on.
> 
>      Thank you for this information, this is good news. I guess I can 
> wait until 5.16.

I think you do not need to wait till 5.16 if you want to try this, 
current Fedora kernels do have this option but it is turned off by 
default as Nils pointed out (ie: without configuration the kernel boots 
into PREEMPT_VOLUNTARY instead of PREEMPT_FULL). I think the option was 
introduced in 5.12 (5.13 certainly has it).

It is very good news if this is going to be ON by default!

Just add "preempt=full" to the boot options line in /etc/default/grub 
and redo the grub configuration file. Do a "dmesg|grep preempt" to check 
that it is active after rebooting.

I am using preempt=full myself for audio work and it is enough for my 
purposes (I used to run the rt patched kernel[*] because the stock 
Fedora kernel was pretty bad in that respect).

Best,
-- Fernando

[*] actually these days I cannot use the rt patched kernel as it is not 
good for running the custom motu sound driver described in the 
linuxmusicians thread on the motu - too many interrupts and context 
switches make the video unusable....