Technical Tip: Transient high system CPU condition with src-vis CPU load

This article describes what to do when a device experiences transient high system CPU (softirq) and a recurring level of src-vis CPU usage in user space.

All supported versions of FortiGate.

src-vis daemon/process is used for device identification configured on the interfaces, and it is used to gather information about the devices operating on the network:

• MAC address.
• IP address.
• Operating system.
• Hostname.
• User name.
• How long ago the device was detected and on which FortiGate interface.

The device experiences transient high system CPU (softirq) and a recurring level of src-vis CPU usage in user space.

A CPU profiling taken at a time of high system CPU would show a pattern like:

0xffffffffa008fc95: 31 capwap_npu_del_vap+0x3565/0x3c60
0xffffffff80543b00: 6 __copy_skb_header+0x1e0/0x4c0
0xffffffff80550124: 6 dev_hard_start_xmit+0x84/0x270

The device-identification is enabled on many interfaces, and disable device identification on all interfaces to clear the issue.