Linux – Imposing Minimum Niceness on a Specific User

limit

Is it possible to limit a specific user's processes to always run with a niceness of at least 15, say?

Best Answer

You can set per-user or per-group nice values using pam_limits and the /etc/security/limits.conf file.

e.g.

username    hard    priority    15

This only affects PAM services which are configured to use the pam_limits module. Depending on your distribution, this is probably already enabled for services like login, cron, atd, sshd, and others. Or you may have to enable it by adding a line like the following to, e.g., /etc/pam.d/login:

session    required   pam_limits.so

See man pam_limits and the comments in /etc/security/limits.conf for details. If you have the PAM doc package installed, there may be additional documentation at /usr/share/doc/libpam-doc/html/sag-pam_limits.html

Related Solutions

Modify ulimit (open files) of a specific process

To change the limits of a running process, you may use the utility command prlimit.

prlimit --pid 12345 --nofile=1024:1024

What that does internally is to call setrlimit(2). The man page of prlimit should contain some useful invocation examples.

Source: https://sig-io.nl/posts/run-time-editing-of-limits-in-linux/

How to Allow User to Prioritize Process to Negative Niceness

The pam_limits.so module can help you there.

It allows you to set certain limits on specific individual users and groups or wildcards or ranges of users and groups.

The limits you can set are typically ulimit settings but also on the number of concurrent login sessions, processes, CPU time, default priority and maximum priority (renice). Check the limits.conf man page for more.

For example you can configure your mindcraft group to have all their processes started with an increased default priority and you can allow them to use the nice and renice commands to increase the priority of their important jobs manually as well instead of only reducing priority.

# /etc/security/limits.conf
# increase default and max prio for members of the mindcraft group
@mindcraft   hard priority -10
@mindcraft   hard nice     -18

Best Answer

Related Solutions

Modify ulimit (open files) of a specific process

How to Allow User to Prioritize Process to Negative Niceness

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