Arch Linux

Xavion

Member

From: Australia

Registered: 2010-03-13

Posts: 38

[SOLVED] Kernels v5.8 and above slow my system down immensely

I last upgraded my desktop computer in early-2014.  Given how great Linux and KDE are, I get by with it just fine.  That is until Kernel v5.8 came along.  In short, it causes my system to run considerably slower.  For example, applications take 2-4 times as long to load.

I didn't notice this problem until a couple of weeks ago as GRUB had defaulted to the LTS kernel (and it was still sub-5.8 at the time).  Once it got bumped up to v5.10, that's when things went pear-shaped.  After doing some quick (downgrade) testing, I noticed that v5.7.12.arch1-1 (of the "linux" package) and v5.4.97-1 (of "linux-lts") are still good.

So, I guess my question is: does anyone know of anything that changed (code- or feature-wise) from Kernels v5.8 onwards that could be causing this?  I'd prefer not to have to upgrade my system hardware unless absolutely necessary, and the idea of running old kernels forever is a potential security hazard.

A screenshot of my basic system information is available here.  Let me know if you would like anything further (or testing to be done).  Thanks in advance for your help.

Last edited by Xavion (2021-03-01 07:39:57)

kokoko3k

Member

Registered: 2008-11-14

Posts: 2,394

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

I'd take a look to the scheduler subsysyem.
Does your cpu reach his maximum clock?

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V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,742

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

I've read somewhere (don't quite remember where) that intel_pstate gets disabled/switched to passive mode on non-skylake+ CPUs with 5.8+ you should currently still be able to enable it with a

intel_pstate=active

on the kernel parameters

Last edited by V1del (2021-02-28 10:38:36)

Xavion

Member

From: Australia

Registered: 2010-03-13

Posts: 38

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

@V1del: Yeah, I read that somewhere too.  It wasn't nearly as well explained, though, so I questioned the relevance.  Anyway, it has done the trick -- so thanks very much for your help.

Thanks also to @kokoko3k for his input, which was along the right lines as well.

kokoko3k

Member

Registered: 2008-11-14

Posts: 2,394

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

Glad you sorted it out, don't forget to mark this thread as [SOLVED].

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Help me to improve ssh-rdp !
Retroarch User? Try my koko-aio shader !

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,794

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

FYI
https://bbs.archlinux.org/viewtopic.php?id=260361

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Xavion

Member

From: Australia

Registered: 2010-03-13

Posts: 38

Re: [SOLVED] Kernels v5.8 and above slow my system down immensely

@ewaller: Thanks, I was hoping to find something like that.  I actually had done a search for "kernel 5.8 slow", but that thread unfortunately didn't show up in the first page of results.  I've just checked and it's not in any of the top 10 pages, despite containing all of those keywords.  If I had've instead searched for "kernel 5.8.1 slowly", that would have made all the difference!

@kokoko3k: Thanks for reminding me how to do it.  I remember looking for a "close thread" (or similar) button and not finding one.  I don't post here much and it had been a few years since I needed to mark something as solved.