switch-to-buffer slow on PGTK

[Jonas Damm]

Hi,
I am using emacs 30 (GNU Emacs 30.0.50 (build 5, x86_64-pc-linux-gnu,
GTK+ Version 3.24.38, cairo version 1.16.0) of 2024-02-01) on Debian
Sway (wayland) on a ryzen 3600G with 32G of fast memory.

switch-to-buffer gets slower and slower, the longer the
machine is running. After starting emacs fresh, its pretty quick. After
around one day of using, the function takes more then 3 seconds to show
the list of buffers and typing to match a buffer name still takes some
seconds to register.

The same issue happens on an older Notebook with emacs 29 (also sway).

Thanks for any help.
Jonas