Documentation for /proc/sys/user/*	kernel version 4.9.0	(c) 2016		Eric Biederman <ebiederm@xmission.com> ============================================================== This file contains the documetation for the sysctl files in/proc/sys/user. The files in this directory can be used to override the defaultlimits on the number of namespaces and other objects that haveper user per user namespace limits. The primary purpose of these limits is to stop programs thatmalfunction and attempt to create a ridiculous number of objects,before the malfunction becomes a system wide problem.  It is theintention that the defaults of these limits are set high enough thatno program in normal operation should run into these limits. The creation of per user per user namespace objects are charged tothe user in the user namespace who created the object andverified to be below the per user limit in that user namespace. The creation of objects is also charged to all of the userswho created user namespaces the creation of the object happensin (user namespaces can be nested) and verified to be below the per userlimits in the user namespaces of those users. This recursive counting of created objects ensures that creating auser namespace does not allow a user to escape their current limits. Currently, these files are in /proc/sys/user: - max_cgroup_namespaces   The maximum number of cgroup namespaces that any user in the current  user namespace may create. - max_ipc_namespaces   The maximum number of ipc namespaces that any user in the current  user namespace may create. - max_mnt_namespaces   The maximum number of mount namespaces that any user in the current  user namespace may create. - max_net_namespaces   The maximum number of network namespaces that any user in the  current user namespace may create. - max_pid_namespaces   The maximum number of pid namespaces that any user in the current  user namespace may create. - max_user_namespaces   The maximum number of user namespaces that any user in the current  user namespace may create. - max_uts_namespaces   The maximum number of user namespaces that any user in the current  user namespace may create.