cosmic-session: heap memory leak — RSS grows to 1.5 GB+ after ~36 hours

[vichugofsl]

Summary

cosmic-session steadily consumes memory over time. After approximately 36 hours of uptime, the process heap grew to 1.53 GB (RSS 1.54 GB), with a recorded peak of 4.05 GB. Expected memory usage for a session manager should be in the tens of MB range.

Environment

• OS: Pop!_OS 24.04 LTS
• Kernel: 6.18.7-76061807-generic
• CPU: 12th Gen Intel Core i7-1255U
• GPU: Intel Alder Lake-UP3 GT2 (Iris Xe Graphics)
• RAM: 40 GB

Steps to reproduce

1. Log in to a COSMIC session normally.
2. Use the desktop as usual (no unusual workloads required).
3. Observe cosmic-session memory after ~24–36 hours of uptime.

Observed behavior

After ~36 hours of uptime, cosmic-session (PID 2697) shows:

VmRSS:    1,573,224 kB  (~1.54 GB)
VmHWM:    4,247,312 kB  (~4.05 GB peak)
VmData:   1,574,712 kB
Heap:     1,567,956 kB  (~1.53 GB — 99.7% of RSS)
VmSwap:         604 kB
Threads:          2
Open FDs:        68

Additional context

• The peak RSS of 4.05 GB suggests the leak may be intermittent or accelerated under certain conditions, then partially reclaimed before settling at ~1.5 GB.
• Restarting the session (logging out/in) temporarily resolves the issue.