What is the range of a PID on Linux and Solaris?

What is the maximum and minimum value for a PID (Process ID) on Linux and Solaris?


From http://www.alexxoid.com/blog/linux/getting-the-max-pid-value-for-linux-process.html:

To get the max PID value that can be assigned to Linux process, run the following command:

cat /proc/sys/kernel/pid_max

On most Linux machines, the result is 32768 (= 215).

However, it can be set to any value up to 4194304 (= 222) if necessary. Servers might have a larger limit to avoid PID collisions, for example.


You've had, and accepted, a Linux answer. On Solaris, the maximum value of a process ID is a kernel tunable parameter — pidmax in /etc/system — that defaults to 30,000 and that can be set anywhere between 266 and 999,999. Note that this is not max_nprocs, which is a kernel tunable parameter with a subtly different function.


The minimum is 1 and usually the maximum is 2^15