Can we change the thread number while running the application?

When I run linear locally, I find there is a `config.proto` where I get some parameters, such as `max_concurrency ` and `num_threads `.

But when I change the  `num_threads `, the efficiency wasn't improved. After I read the src, I wonder whether the `num_threads ` can change through the config, and how can I get the thread number of the application.