diff options
Diffstat (limited to 'man/systemd.resource-control.xml')
| -rw-r--r-- | man/systemd.resource-control.xml | 98 |
1 files changed, 66 insertions, 32 deletions
diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml index 0e98ca78b8..84dbfa2ff3 100644 --- a/man/systemd.resource-control.xml +++ b/man/systemd.resource-control.xml @@ -106,13 +106,21 @@ <para> <variablelist> + <varlistentry> - <term><option>IO</option></term> + <term><option>CPU</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> + <para>Due to the lack of consensus in the kernel community, the CPU controller support on the unified + cgroup hierarchy requires out-of-tree kernel patches. See <ulink + url="https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu">cgroup-v2-cpu.txt</ulink>.</para> + + <para><varname>CPUWeight=</varname> and <varname>StartupCPUWeight=</varname> replace + <varname>CPUShares=</varname> and <varname>StartupCPUShares=</varname>, respectively.</para> + + <para>The <literal>cpuacct</literal> controller does not exist separately on the unified hierarchy.</para> </listitem> </varlistentry> + <varlistentry> <term><option>Memory</option></term> <listitem> @@ -120,6 +128,15 @@ and <varname>MemoryHigh=</varname> are effective only on unified hierarchy.</para> </listitem> </varlistentry> + + <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> @@ -160,30 +177,49 @@ </varlistentry> <varlistentry> + <term><varname>CPUWeight=<replaceable>weight</replaceable></varname></term> + <term><varname>StartupCPUWeight=<replaceable>weight</replaceable></varname></term> + + <listitem> + <para>Assign the specified CPU time weight to the processes executed, if the unified control group hierarchy + is used on the system. These options take an integer value and control the <literal>cpu.weight</literal> + control group attribute. The allowed range is 1 to 10000. Defaults to 100. For details about this control + group attribute, see <ulink + url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink> and <ulink + url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>. + The available CPU time is split up among all units within one slice relative to their CPU time weight.</para> + + <para>While <varname>StartupCPUWeight=</varname> only applies to the startup phase of the system, + <varname>CPUWeight=</varname> applies to normal runtime of the system, and if the former is not set also to + the startup phase. Using <varname>StartupCPUWeight=</varname> allows prioritizing specific services at + boot-up differently than during normal runtime.</para> + + <para>Implies <literal>CPUAccounting=true</literal>.</para> + + <para>These settings are supported only if the unified control group hierarchy is used.</para> + </listitem> + </varlistentry> + + <varlistentry> <term><varname>CPUShares=<replaceable>weight</replaceable></varname></term> <term><varname>StartupCPUShares=<replaceable>weight</replaceable></varname></term> <listitem> - <para>Assign the specified CPU time share weight to the - processes executed. These options take an integer value and - control the <literal>cpu.shares</literal> control group - attribute. The allowed range is 2 to 262144. Defaults to - 1024. For details about this control group attribute, see - <ulink + <para>Assign the specified CPU time share weight to the processes executed. These options take an integer + value and control the <literal>cpu.shares</literal> control group attribute. The allowed range is 2 to + 262144. Defaults to 1024. For details about this control group attribute, see <ulink url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>. - The available CPU time is split up among all units within - one slice relative to their CPU time share weight.</para> + The available CPU time is split up among all units within one slice relative to their CPU time share + weight.</para> - <para>While <varname>StartupCPUShares=</varname> only - applies to the startup phase of the system, - <varname>CPUShares=</varname> applies to normal runtime of - the system, and if the former is not set also to the startup - phase. Using <varname>StartupCPUShares=</varname> allows - prioritizing specific services at boot-up differently than - during normal runtime.</para> + <para>While <varname>StartupCPUShares=</varname> only applies to the startup phase of the system, + <varname>CPUShares=</varname> applies to normal runtime of the system, and if the former is not set also to + the startup phase. Using <varname>StartupCPUShares=</varname> allows prioritizing specific services at + boot-up differently than during normal runtime.</para> - <para>These options imply - <literal>CPUAccounting=true</literal>.</para> + <para>Implies <literal>CPUAccounting=true</literal>.</para> + + <para>These settings are supported only if the legacy control group hierarchy is used.</para> </listitem> </varlistentry> @@ -191,22 +227,20 @@ <term><varname>CPUQuota=</varname></term> <listitem> - <para>Assign the specified CPU time quota to the processes - executed. Takes a percentage value, suffixed with "%". The - percentage specifies how much CPU time the unit shall get at - maximum, relative to the total CPU time available on one - CPU. Use values > 100% for allotting CPU time on more than - one CPU. This controls the - <literal>cpu.cfs_quota_us</literal> control group - attribute. For details about this control group attribute, - see <ulink + <para>Assign the specified CPU time quota to the processes executed. Takes a percentage value, suffixed with + "%". The percentage specifies how much CPU time the unit shall get at maximum, relative to the total CPU time + available on one CPU. Use values > 100% for allotting CPU time on more than one CPU. This controls the + <literal>cpu.max</literal> attribute on the unified control group hierarchy and + <literal>cpu.cfs_quota_us</literal> on legacy. For details about these control group attributes, see <ulink + url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink> and <ulink url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para> - <para>Example: <varname>CPUQuota=20%</varname> ensures that - the executed processes will never get more than 20% CPU time - on one CPU.</para> + <para>Example: <varname>CPUQuota=20%</varname> ensures that the executed processes will never get more than + 20% CPU time on one CPU.</para> <para>Implies <literal>CPUAccounting=true</literal>.</para> + + <para>This setting is supported on both unified and legacy control group hierarchies.</para> </listitem> </varlistentry> |