- attributes.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>CPUShares=</varname></term>
-
- <listitem><para>Assign the specified
- overall CPU time shares to the
- processes executed. Takes an integer
- value. This controls the
- <literal>cpu.shares</literal> control
- group attribute, which defaults to
- 1024. For details about this control
- group attribute see <ulink
- url="http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>MemoryLimit=</varname></term>
- <term><varname>MemorySoftLimit=</varname></term>
-
- <listitem><para>Limit the overall memory usage
- of the executed processes to a certain
- size. Takes a memory size in bytes. If
- the value is suffixed with K, M, G or
- T the specified memory size is parsed
- as Kilobytes, Megabytes, Gigabytes,
- resp. Terabytes (to the base
- 1024). This controls the
- <literal>memory.limit_in_bytes</literal>
- and
- <literal>memory.soft_limit_in_bytes</literal>
- control group attributes. For details
- about these control group attributes
- see <ulink
- url="http://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>DeviceAllow=</varname></term>
- <term><varname>DeviceDeny=</varname></term>
-
- <listitem><para>Control access to
- specific device nodes by the executed processes. Takes two
- space separated strings: a device node
- path (such as
- <filename>/dev/null</filename>)
- followed by a combination of r, w, m
- to control reading, writing resp.
- creating of the specific device node
- by the unit. This controls the
- <literal>devices.allow</literal>
- and
- <literal>devices.deny</literal>
- control group attributes. For details
- about these control group attributes
- see <ulink
- url="http://www.kernel.org/doc/Documentation/cgroups/devices.txt">devices.txt</ulink>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIOWeight=</varname></term>
-
- <listitem><para>Set the default or
- per-device overall block IO weight
- value for the executed
- processes. Takes either a single
- weight value (between 10 and 1000) to
- set the default block IO weight, or a
- space separated pair of a file path
- and a weight value to specify the
- device specific weight value (Example:
- "/dev/sda 500"). The file path may be
- specified as path to a block device
- node or as any other file in which
- case the backing block device of the
- file system of the file is
- determined. This controls the
- <literal>blkio.weight</literal> and
- <literal>blkio.weight_device</literal>
- control group attributes, which
- default to 1000. Use this option
- multiple times to set weights for
- multiple devices. For details about
- these control group attributes see
- <ulink
- url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><varname>BlockIOReadBandwidth=</varname></term>
- <term><varname>BlockIOWriteBandwidth=</varname></term>
-
- <listitem><para>Set the per-device
- overall block IO bandwith limit for
- the executed processes. Takes a space
- separated pair of a file path and a
- bandwith value (in bytes per second)
- to specify the device specific
- bandwidth. The file path may be
- specified as path to a block device
- node or as any other file in which
- case the backing block device of the
- file system of the file is determined.
- If the bandwith is suffixed with K, M,
- G, or T the specified bandwith is
- parsed as Kilobytes, Megabytes,
- Gigabytes, resp. Terabytes (Example:
- "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0
- 5M"). This controls the
- <literal>blkio.read_bps_device</literal>
- and
- <literal>blkio.write_bps_device</literal>
- control group attributes. Use this
- option multiple times to set bandwith
- limits for multiple devices. For
- details about these control group
- attributes see <ulink
- url="http://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para></listitem>
+ attributes. If this option is used
+ multiple times for the same cgroup
+ attribute only the later setting takes
+ effect. If the empty string is
+ assigned to this option the list of
+ attributes is reset, all previous
+ cgroup attribute settings have no
+ effect, including those done with
+ <varname>CPUShares=</varname>,
+ <varname>MemoryLimit=</varname>,
+ <varname>MemorySoftLimit</varname>,
+ <varname>DeviceAllow=</varname>,
+ <varname>DeviceDeny=</varname>,
+ <varname>BlockIOWeight=</varname>,
+ <varname>BlockIOReadBandwidth=</varname>,
+ <varname>BlockIOWriteBandwidth=</varname>.
+ </para></listitem>