forked from mirrors/nixpkgs
573877c1ac
modprobe. * Move the implementation of boot.kernelModules from the udev job to the activation script. This prevents races with the udev job. * Drop references to the "capability" kernel module, which no longer exists. svn path=/nixos/trunk/; revision=33208
141 lines
3.2 KiB
Nix
141 lines
3.2 KiB
Nix
{ config, pkgs, ... }:
|
|
|
|
with pkgs.lib;
|
|
|
|
let
|
|
|
|
cfg = config.services.cgroups;
|
|
|
|
cgconfigConf = pkgs.writeText "cgconfig.conf" cfg.groups;
|
|
|
|
cgrulesConf = pkgs.writeText "cgrules.conf" cfg.rules;
|
|
|
|
in
|
|
|
|
{
|
|
|
|
###### interface
|
|
|
|
options = {
|
|
|
|
services.cgroups.enable = mkOption {
|
|
type = types.bool;
|
|
default = false;
|
|
description = ''
|
|
Whether to enable support for control groups, a Linux kernel
|
|
feature for resource management. It allows you to assign
|
|
processes to groups that share certain resource limits (e.g.,
|
|
CPU or memory). The <command>cgrulesengd</command> daemon
|
|
automatically assigns processes to the right cgroup depending
|
|
on the rules defined in
|
|
<option>services.cgroups.rules</option>.
|
|
'';
|
|
};
|
|
|
|
services.cgroups.groups = mkOption {
|
|
type = types.string;
|
|
default =
|
|
''
|
|
mount {
|
|
cpu = /dev/cgroup/cpu;
|
|
}
|
|
'';
|
|
example =
|
|
''
|
|
mount {
|
|
cpu = /dev/cgroup/cpu;
|
|
cpuacct = /dev/cgroup/cpuacct;
|
|
}
|
|
|
|
# Create a "www" cgroup with a lower share of the CPU (the
|
|
# default is 1024).
|
|
group www {
|
|
cpu {
|
|
cpu.shares = "500";
|
|
}
|
|
}
|
|
'';
|
|
description = ''
|
|
The contents of the <filename>cgconfig.conf</filename>
|
|
configuration file, which defines the cgroups.
|
|
'';
|
|
};
|
|
|
|
services.cgroups.rules = mkOption {
|
|
type = types.string;
|
|
default = "";
|
|
example =
|
|
''
|
|
# All processes executed by the "wwwrun" uid should be
|
|
# assigned to the "www" CPU cgroup.
|
|
wwwrun cpu www
|
|
'';
|
|
description = ''
|
|
The contents of the <filename>cgrules.conf</filename>
|
|
configuration file, which determines to which cgroups
|
|
processes should be assigned by the
|
|
<command>cgrulesengd</command> daemon.
|
|
'';
|
|
};
|
|
|
|
};
|
|
|
|
|
|
###### implementation
|
|
|
|
config = mkIf cfg.enable {
|
|
|
|
environment.systemPackages = [ pkgs.libcgroup ];
|
|
|
|
environment.etc =
|
|
[ { source = cgconfigConf;
|
|
target = "cgconfig.conf";
|
|
}
|
|
{ source = cgrulesConf;
|
|
target = "cgrules.conf";
|
|
}
|
|
];
|
|
|
|
# The daemon requires the userspace<->kernelspace netlink
|
|
# connector.
|
|
boot.kernelModules = [ "cn" ];
|
|
|
|
jobs.cgroups =
|
|
{ startOn = "startup";
|
|
|
|
description = "Control groups daemon";
|
|
|
|
path = [ pkgs.libcgroup pkgs.procps ];
|
|
|
|
preStart =
|
|
''
|
|
cgclear || true
|
|
|
|
# Mount the cgroup hierarchies. Note: we refer to the
|
|
# store path of cgconfig.conf here to ensure that the job
|
|
# gets reloaded if the configuration changes.
|
|
cgconfigparser -l ${cgconfigConf}
|
|
|
|
# Move existing processes to the right cgroup.
|
|
cgclassify --cancel-sticky $(ps --no-headers -eL o tid) || true
|
|
|
|
# Force a restart if the rules change:
|
|
# ${cgrulesConf}
|
|
'';
|
|
|
|
# Run the daemon that moves new processes to the right cgroup.
|
|
exec = "cgrulesengd";
|
|
|
|
daemonType = "fork";
|
|
|
|
postStop =
|
|
''
|
|
cgclear
|
|
'';
|
|
};
|
|
|
|
|
|
};
|
|
|
|
}
|