mjhjmtu

I am starting to work on linux kernels. I am using Linux 4.19.2
https://elixir.bootlin.com/linux/v4.19.2/ident/

I figured out the structure called task_struct which contains all the information in the Process Control Block. When we create a new process, the fork() function is called, which in turn, calls functions like _do_fork() and copy_process() to provide values for the fields in task_struct.

However, I couldn't find out where is the priority of a new process. The field name used for priority in the task_struct structure is prio. Where does it get its value from, when a process is started? Am I going wrong somewhere?

I tried figuring it out from this link https://elixir.bootlin.com/linux/v4.19.2/ident/

This provides a Linux kernels cross-referenced, that I can read. I figured out that to fork a new process, the function _do_fork() calls copy_process() which in turn calls a function called sched_fork().

This is where the priority of the process is initialised using the function normal_prio().