From d5ad4b58388fde8f378590b2d691240755aa05d8 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Wed, 14 May 2014 06:58:25 +0200 Subject: [PATCH] proc.5: 'pid_max' is a system-wide limit on number of threads and processes Since PIDs > /proc/sys/kernel/pid_max are not allocated, this file thus also imposes a system-wide limit on the number of threads and processes. Signed-off-by: Michael Kerrisk --- man5/proc.5 | 3 +++ 1 file changed, 3 insertions(+) diff --git a/man5/proc.5 b/man5/proc.5 index d487e2eac..a106b1797 100644 --- a/man5/proc.5 +++ b/man5/proc.5 @@ -3219,6 +3219,9 @@ file is also nonzero, then the machine will be rebooted. .IR /proc/sys/kernel/pid_max " (since Linux 2.5.34)" This file specifies the value at which PIDs wrap around (i.e., the value in this file is one greater than the maximum PID). +PIDs greater than this value not allocated; +thus, the value in this file also acts as a system-wide limit +on the total number of processes and threads. The default value for this file, 32768, results in the same range of PIDs as on earlier kernels. On 32-bit platforms, 32768 is the maximum value for