Low latency kernel / Massive input lag;

First things first whats the difference between Lubuntu.net, and Lubuntu.me, one says to post on the Ubuntu forums, one says to post here, I hope I have not downloaded a non-legit distro?

Okay so I tried to give lowlatency kernel a try because of audio production, it all worked perfectly for a while, but recently it has caused the OS to become unstable, in the sense that there is HUGE input lag, but oddly only with USB, the rest of the OS does not lag at all.

So I was playing a video game and the game itself was not lagging at all, but the mouse cursor was taking a fair while to catch up to my movements, and also the keyboard, I rebooted to see if it was something else, and each time the same deal, even on a different TTY session.

I ended up removing the kernel, but for some odd reason it kept it when ever I did uname -r it still said lowlatency, so I installed the generic kernel and edited GRUB so I could boot the standard one, and boom no lag anymore. Any ideas?

Lubuntu.net is not related to Ubuntu, nor Lubuntu in anyway. It’s what we call a ‘fan’ site, but we cannot speak as to what’s on it, nor if its valid/invalid; though most of what I’ve seen does appear valid even if sometimes outdated.

http://lubuntu.me/ is controlled by the Lubuntu team, and is related to Ubuntu.

If you’re unsure - do not ask google or other search engines, but I’d suggest asking Ubuntu thru ubuntu.com. You’ll end up at this page https://ubuntu.com/download/flavours to download flavors, which will take you to official team sites - or http://lubuntu.me/ for Lubuntu.

How did you delete the kernel? Tehre is no need to remove it, you can choose which kernel use in grub

Oh damn, well I am pretty sure I got my ISO from the “fan” site, will the ISO be legit / safe?
I just checked and the URLS are all from the cdimage.ubuntu.com/lubuntu thankfully however I downloaded the “alternate” and I see its quite outdated, what is the “alternate” one?
I will be sure to use lubuntu.me in future.

It does say Im on the latest though so since I updated via apt

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=19.04
DISTRIB_CODENAME=disco
DISTRIB_DESCRIPTION=“Ubuntu 19.04”

@hmollercl I used aptitude and apt-get autoremove, It removed it from the apt list, and such but somehow was still installed / in grub.

I just used grub-customizer to change my grub to just use the generic kernel, and remove the low-latency from the list. However I will note the GRUB never shows at all before (I am thinking because of LUKS), but I change the time it shows from 0 to 5 seconds, now it appears after I enter the key for LUKS. (Holding SHIFT or tab or the things to get grub to show did not work).

The standard Lubuntu CD operates as ‘LIVE’ media, ie. you just boot it to run it, and can use it, or click ‘install’. This requires more memory to ‘install’ as Lubuntu is operating plus you need the installer to operate (also be in memory).

The alternate installer is for low-ram machines (defined as 700MB or less) (see https://help.ubuntu.com/community/Lubuntu/Alternate_ISO or https://help.ubuntu.com/community/Lubuntu/Documentation/AlternateInstall) has no ‘live’ mode, reducing the memory used to install the system, it also uses the debian [text] installer (instead of Ubiquity for 18.04 LTS, or Calamares for modern Lubuntu (18.10 up)). The alternate installer was last created for 18.04, not later point releases so it’ll need a lot more updates (and also won’t have HWE enabled by default)

The cdimage.ubuntu.com will be safe, but I’d still compare your checksums of the ISO used as does/did it always point there? Myself I get my ISOs (excluding daily) from my ISP’s mirrror; then validate against the checksums downloaded on a different box from ubuntu.com (https://tutorials.ubuntu.com/tutorial/tutorial-how-to-verify-ubuntu#0 for info on checksums)

Ahh okay, well I did not want a fancy installer :stuck_out_tongue: or live CD anyway XD.

With regards to the checksum I dont have the ISO anymore, I installed Lubuntu a fair while ago, would you recommend re-installing to be safe? I do not remember checking if it was always cdimage.ubuntu.com, :sweat_smile:

I cannot say if you’re safe or not; but I personally am not aware of any malicious ISOs coming from lubuntu.net; but I’d have hoped Linux Mint would be safe, but hasn’t always been (https://blog.linuxmint.com/?p=2994).

You could use debsums to check packages; however it’ll treat any modification you made as a change - so how modified your system is will impact how it’ll appear. It’s your decision, but personally I believe you’re far more likely safe than unsafe, but I cannot know.

Thanks for the help, I re-installed anyway.
With regards to the kernal, I am simply not using it for now.