Increased RAM usage with kernel 6.7

Description:

There's a sudden increase in RAM usage with kernel 6.7, which sounds like a bug to me. Below is the output of the free -h command when starting my Xfce session with the linux 6.7.arch3-1 and linux-lts 6.6.12-1 kernels (which I'm now using because of this problem):

# linux 6.7.arch3-1
               total        used        free      shared  buff/cache   available
Mem:           3,4Gi       1,1Gi       2,1Gi       3,0Mi       541Mi       2,4Gi

# linux-lts 6.6.12-1
               total        used        free      shared  buff/cache   available
Mem:           3,4Gi       762Mi       2,4Gi       3,1Mi       503Mi       2,7Gi

The difference is "only" 300Mi at startup, but then it gets worse over the course of the session, probably reaching 500-600Mi (at least), so that a small machine like this, still usable with the lts kernel and Xfce, starts to become really unusable with the non-lts kernel (basically, it's no longer possible to open even slightly imposing software like Thunderbird in addition to Firefox without exceeding 90% RAM usage).

Additional info:

• package version(s): 6.7.arch3-1
• config and/or log files:
• link to upstream bug report, if any:

Steps to reproduce:

• Upgrade from linux 6.6.10.arch1-1 to 6.7.arch3-1 (or switch between linux and linux-lts) and compare RAM usage