Helper scripts and schedulers explanation

[Mock]

While cachyos wiki is great, the amount of information on this regard feels overwhelming. No matter how much time I read several articles, I can’t figure out what to do. I’ll try to dive with what I want to achieve and what I do understand from which sources. I hope anyone will be able to help me.

I have a PC with Zen 5 AMD Ryzen with 3D-V Cache. I want the amd_pstate to always be guided, like, set it once and never change ever again. For this case, the best decision would be just set it in kernel params for bootloader, right?
I also noticed, that there is amdpstate-guided helper script in cachyos. Which pros and cons does it have, comparing to just setting it by default? Will I have to re-run this script each time I restart my system, if I don’t set guided in kernel params?

Second, the game-performance sciprt on the same wiki page. I don’t understand what it does and when to use it. From the referenced page I can see it can be used as launch option in steam/lutris/etc, is this the best way to use it in my usecase?

Next, the cpupower. From the article, I think it only applies to amd_pstate=active, so I don’t have to worry about it, since I am using guided? Same question goes for next article about AMD P-State Core Performance Boost. Do I even have to do something manually, or other scripts will handle this stuff by itself?

Then there goes 3D-V Cache Optimizer, but that’s probably the easiest to understand part of all. Just enable cache when gaming, do nothing else, correct? I also don’t think other utilities/scripts touches this.

Finally, there are scx_loader article. I just want to use scx_lavd or scx_bpfland by default and never touch anything ever again, how can I do that? And should I also permanently disable ananicy then? How do I even start and always use scx_lavd? Do I have to re-run script each time system starts?

Also, I think anyone who understand all these topics noticed, but I completely don’t understand how all these things correlate to each other. Does game-performance changes amd_pstate? Or like, does enabling scx_bpfland changes something? Which of these changes persistent? How do I disable them? And so on, it’s extremely complicated and not clear at all…

[Franck]

Hi there,

for having lavd permanently is no way posssible. After each update of the sched_ext package (scx_scheds) u need to manually edit the file /etc/default/scx

sudo vi /etc/default/scx

and tere u need to change the line

SCX_SCHEDULER=scx_bpfland

to

SCX_SCHEDULER=scx_lavd (with any option like performance or else)

and reboot

[Whataboard]

Under system cachyos kernel manager second tab you can change the shedular permanently.

[Whataboard]

https://wiki.cachyos.org/configuration/general_system_tweaks/

Link to the pstate tutorial.

[naim]

@Mock

I also noticed, that there is amdpstate-guided helper script in cachyos. Which pros and cons does it have, comparing to just setting it by default?

The script sets the scaling driver to guided and scheduling governor to schedutil at runtime. Did you see the script?

@Mock

Will I have to re-run this script each time I restart my system, if I don’t set guided in kernel params?

Yes, of course.

@Mock

Second, the game-performance sciprt on the same wiki page. I don’t understand what it does and when to use it

Read the script. It sets the power profile to performance and inhibits the screensaver when the launched app is running.

@Mock

From the referenced page I can see it can be used as launch option in steam/lutris/etc, is this the best way to use it in my usecase?

Yes, but what is your usecase?

@Mock

Next, the cpupower. From the article, I think it only applies to amd_pstate=active, so I don’t have to worry about it, since I am using guided?

Correct.

@Mock

Same question goes for next article about AMD P-State Core Performance Boost. Do I even have to do something manually, or other scripts will handle this stuff by itself?

Boost is enabled by default, you can disable it with the command provided in the wiki. There is no helper script for this.

@Mock

Finally, there are scx_loader article. I just want to use scx_lavd or scx_bpfland by default and never touch anything ever again, how can I do that? And should I also permanently disable ananicy then? How do I even start and always use scx_lavd? Do I have to re-run script each time system starts?

Set it from kernel manager or scx systemd service and enable it and it will persist on reboots.

@Mock

Also, I think anyone who understand all these topics noticed, but I completely don’t understand how all these things correlate to each other

Try it yourself on your system. These are all extremely basic questions that you can learn by applying what’s written in the wiki yourself. Just reading will get you nowhere.

[naim]

That file should be backed up so it shouldn’t be overwritten on upgrades.

[Mock]

Thanks for comprehensive answer, this info is exactly what I was looking for!