core/cgroup: introduce MemoryZSwapWriteback setting

Added in
https://github.com/torvalds/linux/commit/501a06fe8e4c185bbda371b8cedbdf1b23a633d8

diff --git a/man/org.freedesktop.systemd1.xml b/man/org.freedesktop.systemd1.xml
index fa2ebb6fe5b6d34d56b272d32a01e4160d02c98d..3a37a636b3c7a955032f4f84322214b8003114b6 100644 (file)
--- a/man/org.freedesktop.systemd1.xml
+++ b/man/org.freedesktop.systemd1.xml
@@ -2916,6 +2916,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -3553,6 +3555,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -4203,6 +4207,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -5013,6 +5019,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -5660,6 +5668,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -6292,6 +6302,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -6976,6 +6988,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -7551,6 +7565,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -8097,6 +8113,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -8904,6 +8922,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -9465,6 +9485,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -9997,6 +10019,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -10663,6 +10687,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -10850,6 +10876,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -11046,6 +11074,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -11266,6 +11296,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t StartupMemoryZSwapMax = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+      readonly b MemoryZSwapWriteback = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly t MemoryLimit = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s DevicePolicy = '...';
@@ -11473,6 +11505,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <!--property StartupMemoryZSwapMax is not documented!-->
 
+    <!--property MemoryZSwapWriteback is not documented!-->
+
     <!--property MemoryLimit is not documented!-->
 
     <!--property DevicePolicy is not documented!-->
@@ -11699,6 +11733,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <variablelist class="dbus-property" generated="True" extra-ref="StartupMemoryZSwapMax"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="MemoryZSwapWriteback"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="MemoryLimit"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="DevicePolicy"/>
@@ -11990,7 +12026,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Socket Unit Objects</title>
@@ -12024,7 +12061,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Mount Unit Objects</title>
@@ -12056,7 +12094,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Swap Unit Objects</title>
@@ -12088,7 +12127,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Slice Unit Objects</title>
@@ -12111,7 +12151,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Scope Unit Objects</title>
@@ -12135,7 +12176,8 @@ $ gdbus introspect --system --dest org.freedesktop.systemd1 \
       <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>
+      <varname>EffectiveTasksMax</varname>, and
+      <varname>MemoryZSwapWriteback</varname> were added in version 256.</para>
     </refsect2>
     <refsect2>
       <title>Job Objects</title>

diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml
index 972e1d231627b53efa073b70744c636f5cf198fe..d5b77dc833fc50708cd1680c645bc28ad4626e38 100644 (file)
--- a/man/systemd.resource-control.xml
+++ b/man/systemd.resource-control.xml
@@ -504,6 +504,23 @@ CPUWeight=20   DisableControllers=cpu              /          \
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term><varname>MemoryZSwapWriteback=</varname></term>
+
+        <listitem>
+          <para>This setting controls the <option>memory</option> controller in the unified hierarchy.</para>
+
+          <para>Takes a boolean argument. When true, pages stored in the Zswap cache are permitted to be
+          written to the backing storage, false otherwise. Defaults to true. This allows disabling
+          writeback of swap pages for IO-intensive applications, while retaining the ability to store
+          compressed pages in Zswap. See the kernel's
+          <ulink url="https://docs.kernel.org/admin-guide/mm/zswap.html">Zswap</ulink> documentation
+          for more details.</para>
+
+          <xi:include href="version-info.xml" xpointer="v256"/>
+        </listitem>
+      </varlistentry>
+
       <varlistentry>
         <term><varname>AllowedMemoryNodes=</varname></term>
         <term><varname>StartupAllowedMemoryNodes=</varname></term>

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index ccbbda47b2f8d7b7a52f626d95c9d79f587cd0e3..fdca434df9bfc8779c9a6ca54e8bd91f15914d86 100644 (file)
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -180,6 +180,8 @@ void cgroup_context_init(CGroupContext *c) {
 
                 .memory_limit = CGROUP_LIMIT_MAX,
 
+                .memory_zswap_writeback = true,
+
                 .io_weight = CGROUP_WEIGHT_INVALID,
                 .startup_io_weight = CGROUP_WEIGHT_INVALID,
 
@@ -423,6 +425,7 @@ int cgroup_context_copy(CGroupContext *dst, const CGroupContext *src) {
         dst->startup_memory_max_set = src->startup_memory_max_set;
         dst->startup_memory_swap_max_set = src->startup_memory_swap_max_set;
         dst->startup_memory_zswap_max_set = src->startup_memory_zswap_max_set;
+        dst->memory_zswap_writeback = src->memory_zswap_writeback;
 
         SET_FOREACH(i, src->ip_address_allow) {
                 r = in_addr_prefix_add(&dst->ip_address_allow, i);
@@ -877,6 +880,7 @@ void cgroup_context_dump(Unit *u, FILE* f, const char *prefix) {
                 "%sStartupMemorySwapMax: %" PRIu64 "%s\n"
                 "%sMemoryZSwapMax: %" PRIu64 "%s\n"
                 "%sStartupMemoryZSwapMax: %" PRIu64 "%s\n"
+                "%sMemoryZSwapWriteback: %s\n"
                 "%sMemoryLimit: %" PRIu64 "\n"
                 "%sTasksMax: %" PRIu64 "\n"
                 "%sDevicePolicy: %s\n"
@@ -921,6 +925,7 @@ void cgroup_context_dump(Unit *u, FILE* f, const char *prefix) {
                 prefix, c->startup_memory_swap_max, format_cgroup_memory_limit_comparison(u, "StartupMemorySwapMax", cdi, sizeof(cdi)),
                 prefix, c->memory_zswap_max, format_cgroup_memory_limit_comparison(u, "MemoryZSwapMax", cdj, sizeof(cdj)),
                 prefix, c->startup_memory_zswap_max, format_cgroup_memory_limit_comparison(u, "StartupMemoryZSwapMax", cdk, sizeof(cdk)),
+                prefix, yes_no(c->memory_zswap_writeback),
                 prefix, c->memory_limit,
                 prefix, cgroup_tasks_max_resolve(&c->tasks_max),
                 prefix, cgroup_device_policy_to_string(c->device_policy),
@@ -2236,6 +2241,7 @@ static void cgroup_context_apply(
                         cgroup_apply_unified_memory_limit(u, "memory.zswap.max", zswap_max);
 
                         (void) set_attribute_and_warn(u, "memory", "memory.oom.group", one_zero(c->memory_oom_group));
+                        (void) set_attribute_and_warn(u, "memory", "memory.zswap.writeback", one_zero(c->memory_zswap_writeback));
 
                 } else {
                         char buf[DECIMAL_STR_MAX(uint64_t) + 1];

diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index ad34f77958748332149ba559444c0dbc1d4cb00d..72fe275e8ca34e023b0e03a13435d9c9748b5cdf 100644 (file)
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -197,6 +197,8 @@ struct CGroupContext {
         bool startup_memory_swap_max_set:1;
         bool startup_memory_zswap_max_set:1;
 
+        bool memory_zswap_writeback;
+
         Set *ip_address_allow;
         Set *ip_address_deny;
         /* These two flags indicate that redundant entries have been removed from

diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 9afc0827e667b8616c27948bd857b45daf9cfbe5..6cb335608b00477bc1a026bf387cbb623b1b52f6 100644 (file)
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -487,6 +487,7 @@ const sd_bus_vtable bus_cgroup_vtable[] = {
         SD_BUS_PROPERTY("StartupMemorySwapMax", "t", NULL, offsetof(CGroupContext, startup_memory_swap_max), 0),
         SD_BUS_PROPERTY("MemoryZSwapMax", "t", NULL, offsetof(CGroupContext, memory_zswap_max), 0),
         SD_BUS_PROPERTY("StartupMemoryZSwapMax", "t", NULL, offsetof(CGroupContext, startup_memory_zswap_max), 0),
+        SD_BUS_PROPERTY("MemoryZSwapWriteback", "b", bus_property_get_bool, offsetof(CGroupContext, memory_zswap_writeback), 0),
         SD_BUS_PROPERTY("MemoryLimit", "t", NULL, offsetof(CGroupContext, memory_limit), 0),
         SD_BUS_PROPERTY("DevicePolicy", "s", property_get_cgroup_device_policy, offsetof(CGroupContext, device_policy), 0),
         SD_BUS_PROPERTY("DeviceAllow", "a(ss)", property_get_device_allow, 0, 0),
@@ -1279,6 +1280,9 @@ int bus_cgroup_set_property(
         if (streq(name, "MemoryLimitScale"))
                 return bus_cgroup_set_memory_scale(u, name, &c->memory_limit, message, flags, error);
 
+        if (streq(name, "MemoryZSwapWriteback"))
+                return bus_cgroup_set_boolean(u, name, &c->memory_zswap_writeback, CGROUP_MASK_MEMORY, message, flags, error);
+
         if (streq(name, "TasksAccounting"))
                 return bus_cgroup_set_boolean(u, name, &c->tasks_accounting, CGROUP_MASK_PIDS, message, flags, error);
 

diff --git a/src/core/execute-serialize.c b/src/core/execute-serialize.c
index 5782c2f175e190d3dbf934e49dfafd130a9104e7..1ae77f39fb96b4464af1ea536043f5e3dc43ff39 100644 (file)
--- a/src/core/execute-serialize.c
+++ b/src/core/execute-serialize.c
@@ -230,6 +230,10 @@ static int exec_cgroup_context_serialize(const CGroupContext *c, FILE *f) {
                         return r;
         }
 
+        r = serialize_bool(f, "exec-cgroup-context-memory-zswap-writeback", c->memory_zswap_writeback);
+        if (r < 0)
+                return r;
+
         if (c->memory_limit != CGROUP_LIMIT_MAX) {
                 r = serialize_item_format(f, "exec-cgroup-context-memory-limit", "%" PRIu64, c->memory_limit);
                 if (r < 0)
@@ -677,6 +681,11 @@ static int exec_cgroup_context_deserialize(CGroupContext *c, FILE *f) {
                         r = safe_atou64(val, &c->startup_memory_zswap_max);
                         if (r < 0)
                                 return r;
+                } else if ((val = startswith(l, "exec-cgroup-context-memory-zswap-writeback="))) {
+                        r = parse_boolean(val);
+                        if (r < 0)
+                                return r;
+                        c->memory_zswap_writeback = r;
                 } else if ((val = startswith(l, "exec-cgroup-context-memory-limit="))) {
                         r = safe_atou64(val, &c->memory_limit);
                         if (r < 0)

diff --git a/src/core/load-fragment-gperf.gperf.in b/src/core/load-fragment-gperf.gperf.in
index 92d5fc4cc3ffc69f1f3f1b19e013cc4b68ea361b..c5ea99726a4d55587dc976baa4d5da28db1da14d 100644 (file)
--- a/src/core/load-fragment-gperf.gperf.in
+++ b/src/core/load-fragment-gperf.gperf.in
@@ -220,6 +220,7 @@
 {{type}}.StartupMemorySwapMax,             config_parse_memory_limit,                   0,                                  offsetof({{type}}, cgroup_context)
 {{type}}.MemoryZSwapMax,                   config_parse_memory_limit,                   0,                                  offsetof({{type}}, cgroup_context)
 {{type}}.StartupMemoryZSwapMax,            config_parse_memory_limit,                   0,                                  offsetof({{type}}, cgroup_context)
+{{type}}.MemoryZSwapWriteback,             config_parse_bool,                           0,                                  offsetof({{type}}, cgroup_context.memory_zswap_writeback)
 {{type}}.MemoryLimit,                      config_parse_memory_limit,                   0,                                  offsetof({{type}}, cgroup_context)
 {{type}}.DeviceAllow,                      config_parse_device_allow,                   0,                                  offsetof({{type}}, cgroup_context)
 {{type}}.DevicePolicy,                     config_parse_device_policy,                  0,                                  offsetof({{type}}, cgroup_context.device_policy)

diff --git a/src/shared/bus-unit-util.c b/src/shared/bus-unit-util.c
index 0fedafd881c384eb9685babab2d24b9d4dc4a966..7d847b94252f79fd5324f166c60562aec11c5259 100644 (file)
--- a/src/shared/bus-unit-util.c
+++ b/src/shared/bus-unit-util.c
@@ -562,6 +562,7 @@ static int bus_append_cgroup_property(sd_bus_message *m, const char *field, cons
 
         if (STR_IN_SET(field, "CPUAccounting",
                               "MemoryAccounting",
+                              "MemoryZSwapWriteback",
                               "IOAccounting",
                               "BlockIOAccounting",
                               "TasksAccounting",