Bug ID 678416: Some tmm/umem_usage_stat counters may be incorrect under memory pressure.

Last Modified: Apr 28, 2025

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Fixed In:
14.0.0, 13.1.0, 12.1.3.4

Opened: Aug 14, 2017

Severity: 2-Critical

Symptoms

After the BIG-IP system experiences severe memory pressure, the 'allocated' and 'max_allocated' counters from the tmm/umem_usage_stat table incorrectly show extremely high values.

Impact

The 'allocated' and 'max_allocated' counters from the tmm/umem_usage_stat table do not reflect actual values. However, there is no functionality issue as a result. This is a cosmetic issue only.

Conditions

The BIG-IP system experiences enough memory pressure that slabs are transferred between threads.

Workaround

None.

Fix Information

The system now manages better under memory pressure so that the tmm/umem_usage_stat counters correctly reflect actual values.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips