Why does the time-consuming increase exponentially when calling NewKnowledgeBaseInstance concurrently?

[kookio111]

Hi,
when i start one thread to run 10000 times match，it takes 500ms，but when i increase the thread count to 10, it takes 4800ms，
and i found each thread takes almost 4800ms too，does the time-consuming increase exponentially when calling NewKnowledgeBaseInstance concurrently?

i'm a chinese，hope you could understand me, i'll appreciate for your response！