It is virtual memory, the real memory size is usually sub 1GB. But I just can’t find any other culprit, and killing WindowServer is the only thing that helps.

I have no idea how to troubleshoot this and don’t really have time for it when working on hotfixes, I just want to get back in a state where I’m not facing an imminent system lock up where I can’t even save my recent work.

Do you tint your mouse cursor (new Monterey accessibility setting)? I noticed this in the last handful of developer betas, and it definitely shipped out in 12.0.1: https://bugzilla.mozilla.org/show_bug.cgi?id=1735345

Although that particular issue will show in application footprint, not WindowServer. I see WindowServer buildup on one of my M1s still, even in 12.1 beta :(

Nope, never used that setting. I just opened Accessibility and hit reset on the pointer colors again just to be sure.

This is a windows technique, but presumably something similar might be available on mac too:

https://randomascii.wordpress.com/2018/02/11/zombie-processe...

Activity Monitor shows a "memory footprint", rather than just a simple sum of virtual memory usage. Among other things, this number splits memory usage for resources shared across multiple processes (e.g. system libraries) and attributes a fraction to each of them.