Bug ID 888517: Busy polling leads to high CPU

Last Modified: Nov 07, 2022

Bug Tracker

Affected Product:  See more info
BIG-IP Install/Upgrade, LTM(all modules)

Known Affected Versions:
13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1

Fixed In:
16.1.0, 16.0.1.2, 15.1.3, 14.1.4.1, 13.1.4

Opened: Mar 09, 2020
Severity: 3-Major

Symptoms

TMM is running at 100 percent CPU even under a light network load. A high number of packet drops and queue full events are reported.

Impact

Busy polling runs the TMM CPU usage to 100 percent.

Conditions

- BIG-IP Virtual Edition. - There are underlying network performance issues causing the transmit queue to be full. For example, a non-SR-IOV virtual machine environment. - Upgrading from BIG-IP v12.x to BIG-IP v14.x.

Workaround

Correct the underlying networking/virtualization issue. Report in logs and mark down interface when its transmitting queue is full.

Fix Information

Providing visible information with an error message when there is busy polling over a period of time. "Marking down interface because its txq[<queue_num>] has been full for n seconds."

Behavior Change