BUG: Multiple Keyboards Lag

[Ryan McClue]

Thanks Carlos,
So, I guess just switch to KDE or an alternative to gnome?
--
Ryan McClue, Sydney

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐

On Monday, October 11th, 2021 at 9:54 AM, Carlos Garnacho <carlosg at gnome.org> wrote:

> Hi,
>
> On Mon, Oct 11, 2021 at 12:16 AM Ryan McClue re.mcclue at protonmail.com wrote:
>
> > PROBLEM:
> >
> > I'm on a fresh install of Ubuntu 20.04 (xorg 1.20.11), with 2 connected keyboards (built-in and USB).
> >
> > When I hit keys on each keyboard simultaneously in a program like firefox, gnome-terminal etc. stalling/lag occurs.
> >
> > It only happens for keyboards it seems as moving an external mouse and trackpad together causes no issues.
> >
> > TO REPRODUCE:
> >
> > To investigate the problem I wrote a simple C file (see attached 'xorg-lag.c', compile with $(gcc xorg-lag.c -o xorg-lag))
> >
> > The program finds keyboard devices under /dev/input/event and uses epoll to poll them for input via the evdev interface.
> >
> > If I start entering keys on one keyboard and then switch to the other, the program stalls briefly.
> >
> > If I simultaneously enter keys on each keyboard the program stalls indefinitely until I stop entering keys.
> >
> > I have tested with different keyboards and experience the same result.
> >
> > If I switch to a virtual terminal and run I experience no lag.
> >
> > This makes me think it is a bug with xorg.
>
> It sounds like you mean
>
> https://gitlab.gnome.org/GNOME/mutter/-/issues/398 (although
>
> https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/1858 has more
>
> recent context). I don't think there's a single culprit here, and
>
> they're likely just indirectly relevant in this mailing list.
>
> Cheers,
>
> Carlos