Issues with Processor Information After Hot-Plugging Cores

This behavior is expected due to the way most operating systems and performance monitoring tools work. When a program starts, it typically initializes its performance counters based on the current system configuration, including the number of CPU cores. If additional cores are hot-plugged while the program is running, the program may not be aware of these new cores, and thus, it can’t monitor them.

Restarting the program allows it to re-initialize its performance counters and detect the newly added cores. This is why a process restart is required to obtain all CPU data correctly after hot-plugging additional cores.

If you need to frequently hot-plug CPU cores and want your program to automatically detect them, you might need to modify your program to periodically re-initialize its performance counters, or use an operating system feature or a third-party library that supports dynamic CPU core detection. However, this could be complex and might not be supported on all platforms.