commit: 6d7713a758b7e78f05e6a3cc101f862d28d778ab Author: William Hubbs <w.d.hubbs <AT> gmail <DOT> com> AuthorDate: Thu Sep 14 15:39:38 2017 +0000 Commit: William Hubbs <williamh <AT> gentoo <DOT> org> CommitDate: Thu Sep 14 15:39:38 2017 +0000 URL: https://gitweb.gentoo.org/proj/openrc.git/commit/?id=6d7713a7
guide.md: clarify cgroups documentation Update the documentation to reflect cgroups version 2 support. Also, add a section on dealing with orphaned service processes. This fixes #94. guide.md | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/guide.md b/guide.md index 7aa23a63..e7e8f4b4 100644 --- a/guide.md +++ b/guide.md @@ -241,17 +241,36 @@ messages to a file), and a few others. # ulimit and CGroups -Setting `ulimit` and `nice` values per service can be done through the `rc_ulimit` -variable. +Setting `ulimit` and `nice` values per service can be done through the +`rc_ulimit` variable. -Under Linux, OpenRC can optionally use CGroups for process management. -By default each service script's processes are migrated to their own CGroup. +Under Linux, OpenRC can use cgroups for process management as well. Once +the kernel is configured appropriately, the `rc_cgroup_mode` setting in +/etc/rc.conf should be used to control whether cgroups version one,, +two, or both are used. The default is to use both if they are available. + +By changing certain settings in the service's `conf.d` file limits can be +enforced per service. These settings are documented in detail in the +default /etc/rc.conf under `LINUX CGROUPS RESOURCE MANAGEMENT`. + +# Dealing with Orphaned Processes + +It is possible to get into a state where there are orphaned processes +running which were part of a service. For example, if you are monitoring +a service with supervise-daemon and supervise-daemon dies for an unknown +reason. The way to deal with this will be different for each system. + +On Linux systems with cgroups enabled, the cgroup_cleanup command is +added to all services. You can run it manually, when the service is +stopped, by using: + +``` +# rc-service someservice cgroup_cleanup +``` + +The `rc_cgroup_cleanup` setting can be changed to yes to make this +happen automatically when the service is stopped. -By changing certain values in the `conf.d` file limits can be enforced per -service. It is easy to find orphan processes of a service that persist after -`stop()`, but by default these will NOT be terminated. -To change this add `rc_cgroup_cleanup="yes"` in the `conf.d` files for services -where you desire this functionality. # Caching
