I am on Ubuntu. Recently I find that vim/vi is broken in the sense that the
movement of cursor within the text is extremely slow. I have to wait for one second for the
cursor to down one row when I press the j or the down arrow key.

This happens for the left, right, up or down key. I have to wait for the cursor to jump one
last step before I start typing. As you can imagine, this is driving me nuts who has used vi for so many years!


This is totally unacceptable.

I do not know how vi is broken.

I have set :set ttyfast but it is not helpful at all.

the options in vi are:

I do not believe the keyboard has any issue since I edit this message using the same keyboard
on this forum site but the cursor movement is almost instantaneous!

is it the same for all files that you open?
maybe the file is too big and that's why it's slow

any settings on your Terminal that might have been accidentally enabled that causes the lag?

have you check, top? and just check whether the CPU or memory whether it operates minimally

have you tried other editor like nano? is it the same?

try another terminal (type), another user, console. Is it the same everywhere?

I am still investigating. I login as another user and try to use vi and the lag is still felt. Seems to be system wide thing. This is nasty. How could vi be broken!

I think my another Ubuntu has no such problem.

So I will record here what I have on this machine. Worse come to worse, I have to do a fresh install of Ubuntu! (just to avoid this unfortunate problem
but I am spending 90% of my time in vi.)

vim version and stuff.

my vi lag is probabilitic! it will land on the exact location if I am lucky or I did very slow cursor movement.

But nano seems OK. May be I shall switch to nano for now.

Only when i need to use complicated vi command then only I switch to vi again. But this is really nonsense!

Try mv'ing any '.vimrc' or system wide vimrc files into a temp back up area for now and reboot.
Also rm (or mv) any .viminfo files.
Does the problem go away - could be a corruption in one of those?

Also, check / be consistent with either vi or vim.
I know some distros just symlink 'vi' to vim, but it it possible to have both.
I'd rm any vi (as opposed to vim) files as well - apart from a binary vi if you have it.

did you try it in gui, or in console mode? Did you try different terminal emulators?

I notice the log above says the vim was recently built. Not sure that is problem but I remember vividly things became weird when I did the apt update; apt upgrade a few days ago. Or it is due to some strange random things but I have been very careful so I think the issue is quite nasty so I made a decision to take a difficult route to
reinstall Ubuntu from scratch!

I installed a new Ubuntu (in fact the latest 24.04 version! ) and even though i paid the price to
redoing everything but at least I recover my vim for my work --- can't do anything vi.

The old ubuntu is still sitting in one partition so it could be booted up if I ever have time/energy to hunt down the root of the problem.

Cheers!

BTW:

if not using wayland:

Did you try using xset(1), see the manual, there is a way to speed up the cursor using xset(1).

I know Ubuntu and many distros has GUI tools for this, but xset(1) always works for me and is portable to the BSDs.

So you've been using Vim on Ubuntu and it was working fine, then - without any changes by you - one day it's not working fine, and you've ruled out hardware failure?

Step 1: search for other people with the same issue, to see if the bug has already been reported.

Step 2: //help.ubuntu.com/stable/ubuntu-help/report-ubuntu-bug.html.en

yes. It was working fine.
Then it broke suddenly.

My company is adopting this Ubuntu scripts to the "hardening" of OS for enhanced security purposes (frankly I do not
know how effective it is -- my understanding is that as long as I do apt update; apt upgrade and adopt some
common security protocol Linux is reasonably secure but then people are paranoid these days), I highly suspect I am a victim of that.
I must admit the old Ubuntu 22.04 was running fine under "hardened" OS but then bad things just happened suddenly.


But for now, I am using the new ubuntu 24.04 on exactly the same hardware and all is good and sound..
Troubleshooting takes time and energy so I will revisit this issue by booting up the broken-vi OS.

Once this 24.04 is hardened, then it might have a problem again. I shall see.

Thanks for suggestions.

Back to my ubuntu 22.04, I think this is a helpful discovery.
I find that as long as I do not change the size of the Terminal, the lag is not observed at all.
So it seems to be pointing to some underlying bug..

At least I just keep the size untouched this could be a temporary solution!

that may mean incorrect TERM settings

Any way, I decided to move to ubuntu 24.04. I have lost confidence in ubuntu22.04 already.

Was busy customizing Gnome 3 to get all these cool extension such as Window List stuff working.
I am now about to work productive again (hopefully!)