Merge pull request #28797 from Werkov/eff_limits

Add MemoryMaxEffective=, MemoryHighEffective= and TasksMaxEff…  …ective= properties

man/org.freedesktop.systemd1.xml

@@ -2806,6 +2806,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -2814,6 +2818,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -3439,6 +3445,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -3447,6 +3457,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -4081,6 +4093,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -4089,6 +4105,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -4885,6 +4903,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -4893,6 +4915,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -5528,6 +5552,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -5536,6 +5564,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -6152,6 +6182,10 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -6160,6 +6194,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -6830,6 +6866,10 @@ node /org/freedesktop/systemd1/unit/home_2emount {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -6838,6 +6878,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -7401,6 +7443,10 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -7409,6 +7455,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -7939,6 +7987,10 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -7947,6 +7999,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -8740,6 +8794,10 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -8748,6 +8806,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -9297,6 +9357,10 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -9305,6 +9369,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -9821,6 +9887,10 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -9829,6 +9899,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -10481,6 +10553,10 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -10489,6 +10565,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -10664,6 +10742,10 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -10672,6 +10754,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -10852,6 +10936,10 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -10860,6 +10948,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -11066,6 +11156,10 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryAvailable = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveMemoryHigh = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t CPUUsageNSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly ay EffectiveCPUs = [...];
@@ -11074,6 +11168,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t TasksCurrent = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly t EffectiveTasksMax = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressBytes = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t IPIngressPackets = ...;
@@ -11269,6 +11365,10 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <!--property MemoryZSwapCurrent is not documented!-->
 
+    <!--property EffectiveMemoryMax is not documented!-->
+
+    <!--property EffectiveMemoryHigh is not documented!-->
+
     <!--property CPUUsageNSec is not documented!-->
 
     <!--property EffectiveCPUs is not documented!-->
@@ -11277,6 +11377,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <!--property TasksCurrent is not documented!-->
 
+    <!--property EffectiveTasksMax is not documented!-->
+
     <!--property IPIngressBytes is not documented!-->
 
     <!--property IPIngressPackets is not documented!-->
@@ -11487,6 +11589,10 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryAvailable"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryMax"/>
+
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveMemoryHigh"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="CPUUsageNSec"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="EffectiveCPUs"/>
@@ -11495,6 +11601,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <variablelist class="dbus-property" generated="True" extra-ref="TasksCurrent"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="EffectiveTasksMax"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressBytes"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="IPIngressPackets"/>
@@ -11888,6 +11996,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Socket Unit Objects</title>
@@ -11919,6 +12030,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Mount Unit Objects</title>
@@ -11948,6 +12062,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Swap Unit Objects</title>
@@ -11977,6 +12094,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Slice Unit Objects</title>
@@ -11997,6 +12117,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Scope Unit Objects</title>
@@ -12018,6 +12141,9 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <varname>MemorySwapCurrent</varname>,
       <varname>MemorySwapPeak</varname>, and
       <varname>MemoryZSwapCurrent</varname> were added in version 255.</para>
+      <para><varname>EffectiveMemoryHigh</varname>,
+      <varname>EffectiveMemoryMax</varname>,
+      <varname>EffectiveTasksMax</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Job Objects</title>

man/systemd.resource-control.xml

@@ -409,7 +409,9 @@ CPUWeight=20   DisableControllers=cpu              /          \
           system. If assigned the
           special value <literal>infinity</literal>, no memory throttling is applied. This controls the
           <literal>memory.high</literal> control group attribute. For details about this control group attribute, see
-          <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+          <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.
+          The effective configuration is reported as <varname>EffectiveMemoryHigh=</varname>
+          (see also <varname>EffectiveMemoryMax=</varname>).</para>
 
           <para>While <varname>StartupMemoryHigh=</varname> applies to the startup and shutdown phases of the system,
           <varname>MemoryHigh=</varname> applies to normal runtime of the system, and if the former is not set also to
@@ -437,7 +439,9 @@ CPUWeight=20   DisableControllers=cpu              /          \
           percentage value may be specified, which is taken relative to the installed physical memory on the system. If
           assigned the special value <literal>infinity</literal>, no memory limit is applied. This controls the
           <literal>memory.max</literal> control group attribute. For details about this control group attribute, see
-          <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.</para>
+          <ulink url="https://docs.kernel.org/admin-guide/cgroup-v2.html#memory-interface-files">Memory Interface Files</ulink>.
+          The effective configuration is reported as <varname>EffectiveMemoryMax=</varname> (the value is
+          the most stringent limit of the unit and parent slices and it is capped by physical memory).</para>
 
           <para>While <varname>StartupMemoryMax=</varname> applies to the startup and shutdown phases of the system,
           <varname>MemoryMax=</varname> applies to normal runtime of the system, and if the former is not set also to
@@ -563,7 +567,8 @@ CPUWeight=20   DisableControllers=cpu              /          \
           limit is applied. This controls the <literal>pids.max</literal> control group attribute. For
           details about this control group attribute, the
           <ulink url="https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html#pid">pids controller
-          </ulink>.</para>
+          </ulink>.
+          The effective configuration is reported as <varname>EffectiveTasksMax=</varname>.</para>
 
           <para>The system default for this setting may be controlled with
           <varname>DefaultTasksMax=</varname> in

src/core/cgroup.c

@@ -4555,6 +4555,57 @@ int unit_get_ip_accounting(
         return r;
 }
 
+static uint64_t unit_get_effective_limit_one(Unit *u, CGroupLimitType type) {
+        CGroupContext *cc;
+
+        assert(u);
+        assert(UNIT_HAS_CGROUP_CONTEXT(u));
+
+        if (unit_has_name(u, SPECIAL_ROOT_SLICE))
+                switch (type) {
+                        case CGROUP_LIMIT_MEMORY_MAX:
+                        case CGROUP_LIMIT_MEMORY_HIGH:
+                                return physical_memory();
+                        case CGROUP_LIMIT_TASKS_MAX:
+                                return system_tasks_max();
+                        default:
+                                assert_not_reached();
+                }
+
+        cc = unit_get_cgroup_context(u);
+        switch (type) {
+                /* Note: on legacy/hybrid hierarchies memory_max stays CGROUP_LIMIT_MAX unless configured
+                 * explicitly. Effective value of MemoryLimit= (cgroup v1) is not implemented. */
+                case CGROUP_LIMIT_MEMORY_MAX:
+                        return cc->memory_max;
+                case CGROUP_LIMIT_MEMORY_HIGH:
+                        return cc->memory_high;
+                case CGROUP_LIMIT_TASKS_MAX:
+                        return cgroup_tasks_max_resolve(&cc->tasks_max);
+                default:
+                        assert_not_reached();
+        }
+}
+
+int unit_get_effective_limit(Unit *u, CGroupLimitType type, uint64_t *ret) {
+        uint64_t infimum;
+
+        assert(u);
+        assert(ret);
+        assert(type >= 0);
+        assert(type < _CGROUP_LIMIT_TYPE_MAX);
+
+        if (!UNIT_HAS_CGROUP_CONTEXT(u))
+                return -EINVAL;
+
+        infimum = unit_get_effective_limit_one(u, type);
+        for (Unit *slice = UNIT_GET_SLICE(u); slice; slice = UNIT_GET_SLICE(slice))
+                infimum = MIN(infimum, unit_get_effective_limit_one(slice, type));
+
+        *ret = infimum;
+        return 0;
+}
+
 static int unit_get_io_accounting_raw(Unit *u, uint64_t ret[static _CGROUP_IO_ACCOUNTING_METRIC_MAX]) {
         static const char *const field_names[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = {
                 [CGROUP_IO_READ_BYTES]       = "rbytes=",
@@ -4975,3 +5026,11 @@ static const char* const cgroup_memory_accounting_metric_table[_CGROUP_MEMORY_AC
 };
 
 DEFINE_STRING_TABLE_LOOKUP(cgroup_memory_accounting_metric, CGroupMemoryAccountingMetric);
+
+static const char *const cgroup_limit_type_table[_CGROUP_LIMIT_TYPE_MAX] = {
+        [CGROUP_LIMIT_MEMORY_MAX]  = "EffectiveMemoryMax",
+        [CGROUP_LIMIT_MEMORY_HIGH] = "EffectiveMemoryHigh",
+        [CGROUP_LIMIT_TASKS_MAX]   = "EffectiveTasksMax",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(cgroup_limit_type, CGroupLimitType);

src/core/cgroup.h

@@ -277,6 +277,15 @@ typedef enum CGroupMemoryAccountingMetric {
         _CGROUP_MEMORY_ACCOUNTING_METRIC_INVALID = -EINVAL,
 } CGroupMemoryAccountingMetric;
 
+/* Used for limits whose value sets have infimum */
+typedef enum CGroupLimitType {
+        CGROUP_LIMIT_MEMORY_MAX,
+        CGROUP_LIMIT_MEMORY_HIGH,
+        CGROUP_LIMIT_TASKS_MAX,
+        _CGROUP_LIMIT_TYPE_MAX,
+        _CGROUP_LIMIT_INVALID = -EINVAL,
+} CGroupLimitType;
+
 typedef struct Unit Unit;
 typedef struct Manager Manager;
 typedef enum ManagerState ManagerState;
@@ -388,6 +397,7 @@ int unit_get_tasks_current(Unit *u, uint64_t *ret);
 int unit_get_cpu_usage(Unit *u, nsec_t *ret);
 int unit_get_io_accounting(Unit *u, CGroupIOAccountingMetric metric, bool allow_cache, uint64_t *ret);
 int unit_get_ip_accounting(Unit *u, CGroupIPAccountingMetric metric, uint64_t *ret);
+int unit_get_effective_limit(Unit *u, CGroupLimitType type, uint64_t *ret);
 
 int unit_reset_cpu_accounting(Unit *u);
 void unit_reset_memory_accounting_last(Unit *u);
@@ -439,5 +449,8 @@ CGroupIPAccountingMetric cgroup_ip_accounting_metric_from_string(const char *s)
 const char* cgroup_io_accounting_metric_to_string(CGroupIOAccountingMetric m) _const_;
 CGroupIOAccountingMetric cgroup_io_accounting_metric_from_string(const char *s) _pure_;
 
+const char* cgroup_limit_type_to_string(CGroupLimitType m) _const_;
+CGroupLimitType cgroup_limit_type_from_string(const char *s) _pure_;
+
 const char* cgroup_memory_accounting_metric_to_string(CGroupMemoryAccountingMetric m) _const_;
 CGroupMemoryAccountingMetric cgroup_memory_accounting_metric_from_string(const char *s) _pure_;

src/core/dbus-unit.c

@@ -1426,6 +1426,28 @@ static int property_get_io_counter(
         return sd_bus_message_append(reply, "t", value);
 }
 
+static int property_get_effective_limit(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        uint64_t value = CGROUP_LIMIT_MAX;
+        Unit *u = ASSERT_PTR(userdata);
+        ssize_t type;
+
+        assert(bus);
+        assert(reply);
+        assert(property);
+
+        assert_se((type = cgroup_limit_type_from_string(property)) >= 0);
+        (void) unit_get_effective_limit(u, type, &value);
+        return sd_bus_message_append(reply, "t", value);
+}
+
 int bus_unit_method_attach_processes(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
         _cleanup_set_free_ Set *pids = NULL;
@@ -1547,10 +1569,13 @@ const sd_bus_vtable bus_unit_cgroup_vtable[] = {
         SD_BUS_PROPERTY("MemorySwapPeak", "t", property_get_memory_accounting, 0, 0),
         SD_BUS_PROPERTY("MemoryZSwapCurrent", "t", property_get_memory_accounting, 0, 0),
         SD_BUS_PROPERTY("MemoryAvailable", "t", property_get_available_memory, 0, 0),
+        SD_BUS_PROPERTY("EffectiveMemoryMax", "t", property_get_effective_limit, 0, 0),
+        SD_BUS_PROPERTY("EffectiveMemoryHigh", "t", property_get_effective_limit, 0, 0),
         SD_BUS_PROPERTY("CPUUsageNSec", "t", property_get_cpu_usage, 0, 0),
         SD_BUS_PROPERTY("EffectiveCPUs", "ay", property_get_cpuset_cpus, 0, 0),
         SD_BUS_PROPERTY("EffectiveMemoryNodes", "ay", property_get_cpuset_mems, 0, 0),
         SD_BUS_PROPERTY("TasksCurrent", "t", property_get_current_tasks, 0, 0),
+        SD_BUS_PROPERTY("EffectiveTasksMax", "t", property_get_effective_limit, 0, 0),
         SD_BUS_PROPERTY("IPIngressBytes", "t", property_get_ip_counter, 0, 0),
         SD_BUS_PROPERTY("IPIngressPackets", "t", property_get_ip_counter, 0, 0),
         SD_BUS_PROPERTY("IPEgressBytes", "t", property_get_ip_counter, 0, 0),

src/shared/bus-print-properties.c

@@ -164,9 +164,11 @@ static int bus_print_property(const char *name, const char *expected_value, sd_b
 
                         bus_print_property_value(name, expected_value, flags, "[not set]");
 
-                else if ((ENDSWITH_SET(name, "MemoryLow", "MemoryMin", "MemoryHigh", "MemoryMax", "MemorySwapMax", "MemoryZSwapMax", "MemoryLimit") &&
+                else if ((ENDSWITH_SET(name, "MemoryLow", "MemoryMin",
+                                             "MemoryHigh", "MemoryMax",
+                                             "MemorySwapMax", "MemoryZSwapMax", "MemoryLimit") &&
                           u == CGROUP_LIMIT_MAX) ||
-                         (STR_IN_SET(name, "TasksMax", "DefaultTasksMax") && u == UINT64_MAX) ||
+                         (endswith(name, "TasksMax") && u == UINT64_MAX) ||
                          (startswith(name, "Limit") && u == UINT64_MAX) ||
                          (startswith(name, "DefaultLimit") && u == UINT64_MAX))
 

test/units/testsuite-05.effective-limit.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+# shellcheck source=test/units/util.sh
+. "$(dirname "$0")"/util.sh
+
+pre=test05
+cat >/run/systemd/system/"$pre"alpha.slice <<EOF
+[Slice]
+MemoryMax=40M
+MemoryHigh=40M
+TasksMax=400
+EOF
+
+cat >/run/systemd/system/"$pre"alpha-beta.slice <<EOF
+[Slice]
+MemoryMax=10M
+MemoryHigh=10M
+TasksMax=100
+EOF
+
+cat >/run/systemd/system/"$pre"alpha-beta-gamma.slice <<EOF
+[Slice]
+MemoryMax=20M
+MemoryHigh=20M
+TasksMax=200
+EOF
+
+systemctl daemon-reload
+
+srv=probe.service
+slc0="$pre"alpha.slice
+slc="$pre"alpha-beta-gamma.slice
+
+systemd-run --unit "$srv" --slice "$slc"  \
+    -p MemoryMax=5M \
+    -p MemoryHigh=5M \
+    -p TasksMax=50 \
+    sleep inf
+
+# Compare with inequality because test can run in a constrained container
+assert_le "$(systemctl show -P EffectiveMemoryMax "$srv")" "5242880"
+assert_le "$(systemctl show -P EffectiveMemoryHigh "$srv")" "5242880"
+assert_le "$(systemctl show -P EffectiveTasksMax "$srv")" "50"
+
+systemctl stop "$srv"
+
+systemd-run --unit "$srv" --slice "$slc"  \
+    sleep inf
+
+assert_le "$(systemctl show -P EffectiveMemoryMax "$srv")" "10485760"
+assert_le "$(systemctl show -P EffectiveMemoryHigh "$srv")" "10485760"
+assert_le "$(systemctl show -P EffectiveTasksMax "$srv")" "100"
+
+systemctl set-property "$slc0" \
+    MemoryMax=5M \
+    MemoryHigh=5M \
+    TasksMax=50
+
+assert_le "$(systemctl show -P EffectiveMemoryMax "$srv")" "5242880"
+assert_le "$(systemctl show -P EffectiveMemoryHigh "$srv")" "5242880"
+assert_le "$(systemctl show -P EffectiveTasksMax "$srv")" "50"
+
+systemctl stop "$srv"
+
+rm -f /run/systemd/system/"$pre"* || :

test/units/testsuite-05.rlimit.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+P=/run/systemd/system.conf.d
+mkdir $P
+
+cat >$P/rlimits.conf <<EOF
+[Manager]
+DefaultLimitNOFILE=10000:16384
+EOF
+
+systemctl daemon-reload
+
+[[ "$(systemctl show -P DefaultLimitNOFILESoft)" = "10000" ]]
+[[ "$(systemctl show -P DefaultLimitNOFILE)" = "16384" ]]
+
+[[ "$(systemctl show -P LimitNOFILESoft testsuite-05.service)" = "10000" ]]
+[[ "$(systemctl show -P LimitNOFILE testsuite-05.service)" = "16384" ]]
+
+# shellcheck disable=SC2016
+systemd-run --wait -t bash -c '[[ "$(ulimit -n -S)" = "10000" ]]'
+# shellcheck disable=SC2016
+systemd-run --wait -t bash -c '[[ "$(ulimit -n -H)" = "16384" ]]'

test/units/testsuite-05.service

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 [Unit]
-Description=TEST-05-RLIMITS
+Description=TEST-05-LIMITS
 
 [Service]
 ExecStartPre=rm -f /failed /testok

test/units/testsuite-05.sh

@@ -3,25 +3,9 @@
 set -eux
 set -o pipefail
 
-P=/run/systemd/system.conf.d
+# shellcheck source=test/units/test-control.sh
-mkdir $P
+. "$(dirname "$0")"/test-control.sh
 
-cat >$P/rlimits.conf <<EOF
+run_subtests
-[Manager]
-DefaultLimitNOFILE=10000:16384
-EOF
-
-systemctl daemon-reload
-
-[[ "$(systemctl show -P DefaultLimitNOFILESoft)" = "10000" ]]
-[[ "$(systemctl show -P DefaultLimitNOFILE)" = "16384" ]]
-
-[[ "$(systemctl show -P LimitNOFILESoft testsuite-05.service)" = "10000" ]]
-[[ "$(systemctl show -P LimitNOFILE testsuite-05.service)" = "16384" ]]
-
-# shellcheck disable=SC2016
-systemd-run --wait -t bash -c '[[ "$(ulimit -n -S)" = "10000" ]]'
-# shellcheck disable=SC2016
-systemd-run --wait -t bash -c '[[ "$(ulimit -n -H)" = "16384" ]]'
 
 touch /testok

test/units/util.sh

@@ -28,6 +28,15 @@ assert_eq() {(
     fi
 )}
 
+assert_le() {(
+    set +ex
+
+    if [[ "${1:?}" -gt "${2:?}" ]]; then
+        echo "FAIL: '$1' > '$2'" >&2
+        exit 1
+    fi
+)}
+
 assert_in() {(
     set +ex