Linux Process Management Concepts: Difference between revisions

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=Process=
=Process=
=Threads=
The number of threads for process can be read from the process' corresponding /proc/<pid>/status, as described here: [[Linux_Process_Information#Threads|"Threads:"]].


=Maximum Number of Processes Allowed on the System=
=Maximum Number of Processes Allowed on the System=

Revision as of 04:00, 22 April 2017

Internal

Process

Threads

The number of threads for process can be read from the process' corresponding /proc/<pid>/status, as described here: "Threads:".

Maximum Number of Processes Allowed on the System

cat /proc/sys/kernel/pid_max

or

sysctl kernel.pid_max

For more details, see sysctl.

To get the actual number of processes present in the system, see /proc/stat.

Maximum Number of Processes Available to a Single User

The current value can be read and set with ulimit -u.

For Java applications, this setting limits the number of threads a JVM can create, and it can cause the JVM to throw "java.lang.OutOfMemoryError: unable to create new native thread" exceptions when that limit is reached. For more details see

Java Threads and Linux Processes

The O/S level symptom of reaching the per-user process limit is:

-bash: fork: retry: Resource temporarily unavailable

while trying to execute an arbitrary process.