Want to confirm the expected behavior of OpenDKIM's virtual memory (VSZ) usage

[wuwei19910307]

Hello, here is my question

Inquiry:

We conducted a server load test using a self-built mail server, simulating high-volume email transmission and reception over a short period.

Question 1:
During the load test, OpenDKIM’s virtual memory (VSZ) usage increased.
However, after the test completed, it continued to retain a certain amount of virtual memory (VSZ).
Is this expected behavior?

At the start, memory usage was around 200MB,
at the end of the test it remained around 1GB,
and the peak usage reached 1.1GB.

Please refer to the attached file for details on virtual memory (VSZ) usage during the test.

Question 2:

In my environment, OpenDKIM continued to hold 1GB of virtual memory (VSZ) even after restarting the service and rebooting the OS.
Is this also expected behavior?

Question 3:
If this is expected, could you briefly explain which part of the source code leads to this behavior?

Environment Information:

Virtual server on VMware ESXi

Server OS: Red Hat 8.10

CPU: 2 cores

Memory: 7.5 GiB