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-rw-r--r--man/systemd.resource-control.xml49
1 files changed, 49 insertions, 0 deletions
diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml
index 313a49a959..066f2cc19b 100644
--- a/man/systemd.resource-control.xml
+++ b/man/systemd.resource-control.xml
@@ -99,6 +99,31 @@
</refsect1>
<refsect1>
+ <title>Unified and Legacy Control Group Hierarchies</title>
+
+ <para>Unified control group hierarchy is the new version of kernel control group interface. Depending on the
+ resource type, there are differences in resource control capabilities. Also, because of interface changes, some
+ resource types have a separate set of options on the unified hierarchy.</para>
+
+ <para>
+ <variablelist>
+ <varlistentry>
+ <term><option>IO</option></term>
+ <listitem>
+ <para><varname>IO</varname> prefixed settings are superset of and replace <varname>BlockIO</varname>
+ prefixed ones. On unified hierarchy, IO resource control also applies to buffered writes.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+
+ <para>To ease the transition, there is best-effort translation between the two versions of settings. If all
+ settings of a unit for a given resource type are for the other hierarchy type, the settings are translated and
+ applied. If there are any valid settings for the hierarchy in use, all translations are disabled for the resource
+ type. Mixing the two types of settings on a unit can lead to confusing results.</para>
+ </refsect1>
+
+ <refsect1>
<title>Options</title>
<para>Units of the types listed above can have settings
@@ -337,6 +362,30 @@
</varlistentry>
<varlistentry>
+ <term><varname>IOReadIOPSMax=<replaceable>device</replaceable> <replaceable>IOPS</replaceable></varname></term>
+ <term><varname>IOWriteIOPSMax=<replaceable>device</replaceable> <replaceable>IOPS</replaceable></varname></term>
+
+ <listitem>
+ <para>Set the per-device overall block I/O IOs-Per-Second maximum limit for the executed processes, if the
+ unified control group hierarchy is used on the system. This limit is not work-conserving and the executed
+ processes are not allowed to use more even if the device has idle capacity. Takes a space-separated pair of
+ a file path and an IOPS value to specify the device specific IOPS. The file path may be a 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
+ used. If the IOPS is suffixed with K, M, G, or T, the specified IOPS is parsed as KiloIOPS, MegaIOPS,
+ GigaIOPS, or TeraIOPS, respectively, to the base of 1000. (Example:
+ "/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 1K"). This controls the <literal>io.max</literal> control
+ group attributes. Use this option multiple times to set IOPS limits for multiple devices. For details about
+ this control group attribute, see <ulink
+ url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.
+ </para>
+
+ <para>Implies <literal>IOAccounting=true</literal>.</para>
+
+ <para>This setting is supported only if the unified control group hierarchy is used.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><varname>BlockIOAccounting=</varname></term>
<listitem>