Referring to this question maximum-number-of-processes-in-linux
I under stand that kernel.pid_max affects the maximum value for PID and max user processes in /etc/security/limits.conf file affects total number of processes for each user.
so if this is the right information, if for example pid_max is 10 and max user process is 30609. I think that Kernel will limit no of processes to 10 because there is no more available PIDs.
NOTE : the example is for understanding only