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  • Said İmamoğlu thinks this is interesting:

The system identifies processes by a unique process identification value or PID. The PID is a numerical value represented by the opaque type4 pid_t, which is typically an int. Because of backward compatibility with earlier Unix and Linux versions, however, the default maximum value is only 32,768 (that of a short int), although the value optionally can be increased as high as four million (this is controlled in <linux/threads.h>. The kernel stores this value as pid inside each process descriptor.


Cover of Linux Kernel Development, Third Edition