cgroup: get rid of MemorySoftLimit=

The cgroup attribute memory.soft_limit_in_bytes is unlikely to stay
around in the kernel for good, so let's not expose it for now. We can
readd something like it later when the kernel guys decided on a final
API for this.

9 files changed, 12 insertions, 43 deletions

diff --git a/TODO b/TODO
index 6a96c7781a..d109e01f71 100644
--- a/TODO
+++ b/TODO
@@ -60,8 +60,6 @@ Features:
 
 * always set memory.user_hierarchy for all cgroups we create
 
-* Get rid of MemorySoftLimit=
-
 * After coming back from hibernation reset hibernation swap partition
 
 * mounts: do not test each mount unit against each other mount unit to
diff --git a/man/systemd.cgroup.xml b/man/systemd.cgroup.xml
index cc0eb15abb..ac5896233c 100644
--- a/man/systemd.cgroup.xml
+++ b/man/systemd.cgroup.xml
@@ -136,22 +136,17 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>.
 
       <varlistentry>
         <term><varname>MemoryLimit=<replaceable>bytes</replaceable></varname></term>
-        <term><varname>MemorySoftLimit=<replaceable>bytes</replaceable></varname></term>
 
         <listitem>
-          <para>Specify the hard and soft limits on maximum memory
-          usage of the executed processes. The "hard" limit specifies
-          how much process and kernel memory can be used by tasks in
-          this unit, when there is no memory contention. If the kernel
-          detects memory contention, memory reclaim will be performed
-          until the memory usage is within the "soft" limit. Takes a
+          <para>Specify the limit on maximum memory usage of the
+          executed processes. The limit specifies how much process and
+          kernel memory can be used by tasks in this unit. 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, or Terabytes (with the base 1024),
           respectively. 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,
+          <literal>memory.limit_in_bytes</literal> control group
+          attribute. For details about this control group attribute,
           see <ulink
           url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>.</para>
 
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 9277dd69f6..d10f205a2f 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -33,7 +33,7 @@ void cgroup_context_init(CGroupContext *c) {
          * structure is preinitialized to 0 */
 
         c->cpu_shares = 1024;
-        c->memory_limit = c->memory_soft_limit = (uint64_t) -1;
+        c->memory_limit = (uint64_t) -1;
         c->blockio_weight = 1000;
 }
 
@@ -94,7 +94,6 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                 "%sCPUShares=%lu\n"
                 "%sBlockIOWeight=%lu\n"
                 "%sMemoryLimit=%" PRIu64 "\n"
-                "%sMemorySoftLimit=%" PRIu64 "\n"
                 "%sDevicePolicy=%s\n",
                 prefix, yes_no(c->cpu_accounting),
                 prefix, yes_no(c->blockio_accounting),
@@ -102,7 +101,6 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                 prefix, c->cpu_shares,
                 prefix, c->blockio_weight,
                 prefix, c->memory_limit,
-                prefix, c->memory_soft_limit,
                 prefix, cgroup_device_policy_to_string(c->device_policy));
 
         LIST_FOREACH(device_allow, a, c->device_allow)
@@ -265,15 +263,6 @@ void cgroup_context_apply(CGroupContext *c, CGroupControllerMask mask, const cha
 
                 if (r < 0)
                         log_error("Failed to set memory.limit_in_bytes on %s: %s", path, strerror(-r));
-
-                if (c->memory_soft_limit != (uint64_t) -1) {
-                        sprintf(buf, "%" PRIu64 "\n", c->memory_soft_limit);
-                        r = cg_set_attribute("memory", path, "memory.soft_limit_in_bytes", buf);
-                } else
-                        r = cg_set_attribute("memory", path, "memory.soft_limit_in_bytes", "-1");
-
-                if (r < 0)
-                        log_error("Failed to set memory.soft_limit_in_bytes on %s: %s", path, strerror(-r));
         }
 
         if (mask & CGROUP_DEVICE) {
@@ -336,8 +325,7 @@ CGroupControllerMask cgroup_context_get_mask(CGroupContext *c) {
                 mask |= CGROUP_BLKIO;
 
         if (c->memory_accounting ||
-            c->memory_limit != (uint64_t) -1 ||
-            c->memory_soft_limit != (uint64_t) -1)
+            c->memory_limit != (uint64_t) -1)
                 mask |= CGROUP_MEMORY;
 
         if (c->device_allow || c->device_policy != CGROUP_AUTO)
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index 786bd71c8b..0a079e909d 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -77,7 +77,6 @@ struct CGroupContext {
         LIST_HEAD(CGroupBlockIODeviceBandwidth, blockio_device_bandwidths);
 
         uint64_t memory_limit;
-        uint64_t memory_soft_limit;
 
         CGroupDevicePolicy device_policy;
         LIST_HEAD(CGroupDeviceAllow, device_allow);
diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 1f2a396a6d..9ebcad9da6 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -133,7 +133,6 @@ const BusProperty bus_cgroup_context_properties[] = {
         { "BlockIOWriteBandwidth",   bus_cgroup_append_device_bandwidths, "a(st)", 0                                           },
         { "MemoryAccounting",        bus_property_append_bool,            "b",     offsetof(CGroupContext, memory_accounting)  },
         { "MemoryLimit",             bus_property_append_uint64,          "t",     offsetof(CGroupContext, memory_limit)       },
-        { "MemorySoftLimit",         bus_property_append_uint64,          "t",     offsetof(CGroupContext, memory_soft_limit)  },
         { "DevicePolicy",            bus_cgroup_append_device_policy,     "s",     offsetof(CGroupContext, device_policy)      },
         { "DeviceAllow",             bus_cgroup_append_device_allow,      "a(ss)", 0                                           },
         {}
@@ -418,21 +417,16 @@ int bus_cgroup_set_property(
 
                 return 1;
 
-        } else if (streq(name, "MemoryLimit") || streq(name, "MemorySoftLimit")) {
+        } else if (streq(name, "MemoryLimit")) {
 
                 if (dbus_message_iter_get_arg_type(i) != DBUS_TYPE_UINT64)
                         return -EINVAL;
 
                 if (mode != UNIT_CHECK) {
                         uint64_t limit;
-
                         dbus_message_iter_get_basic(i, &limit);
 
-                        if (streq(name, "MemoryLimit"))
-                                c->memory_limit = limit;
-                        else
-                                c->memory_soft_limit = limit;
-
+                        c->memory_limit = limit;
                         unit_write_drop_in_private_format(u, mode, name, "%s=%" PRIu64, name, limit);
                 }
 
diff --git a/src/core/dbus-cgroup.h b/src/core/dbus-cgroup.h
index 4ce1e7e7fa..e5ac4c3af7 100644
--- a/src/core/dbus-cgroup.h
+++ b/src/core/dbus-cgroup.h
@@ -37,7 +37,6 @@
         "  <property name=\"BlockIOWriteBandwidth=\" type=\"a(st)\" access=\"read\"/>\n" \
         "  <property name=\"MemoryAccounting\" type=\"b\" access=\"read\"/>\n" \
         "  <property name=\"MemoryLimit\" type=\"t\" access=\"read\"/>\n" \
-        "  <property name=\"MemorySoftLimit\" type=\"t\" access=\"read\"/>\n" \
         "  <property name=\"DevicePolicy\" type=\"s\" access=\"read\"/>\n" \
         "  <property name=\"DeviceAllow\" type=\"a(ss)\" access=\"read\"/>\n"
 
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 33c6880b5d..25bd3aae47 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -89,7 +89,6 @@ $1.CPUAccounting,                config_parse_bool,                  0,
 $1.CPUShares,                    config_parse_cpu_shares,            0,                             offsetof($1, cgroup_context)
 $1.MemoryAccounting,             config_parse_bool,                  0,                             offsetof($1, cgroup_context.memory_accounting)
 $1.MemoryLimit,                  config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
-$1.MemorySoftLimit,              config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
 $1.DeviceAllow,                  config_parse_device_allow,          0,                             offsetof($1, cgroup_context)
 $1.DevicePolicy,                 config_parse_device_policy,         0,                             offsetof($1, cgroup_context.device_policy)
 $1.BlockIOAccounting,            config_parse_bool,                  0,                             offsetof($1, cgroup_context.blockio_accounting)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index cfc6f078a6..74454abe49 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -2036,14 +2036,11 @@ int config_parse_memory_limit(
                 void *userdata) {
 
         CGroupContext *c = data;
-        uint64_t *limit;
         off_t bytes;
         int r;
 
-        limit = streq(lvalue, "MemoryLimit") ? &c->memory_limit : &c->memory_soft_limit;
-
         if (isempty(rvalue)) {
-                *limit = (uint64_t) -1;
+                c->memory_limit = (uint64_t) -1;
                 return 0;
         }
 
@@ -2056,7 +2053,7 @@ int config_parse_memory_limit(
                 return 0;
         }
 
-        *limit = (uint64_t) bytes;
+        c->memory_limit = (uint64_t) bytes;
         return 0;
 }
 
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 57e5bb941b..62b5616d80 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -3657,7 +3657,7 @@ static int append_assignment(DBusMessageIter *iter, const char *assignment) {
                     !dbus_message_iter_append_basic(&sub, DBUS_TYPE_BOOLEAN, &b))
                         return log_oom();
 
-        } else if (streq(field, "MemoryLimit") || streq(field, "MemorySoftLimit")) {
+        } else if (streq(field, "MemoryLimit")) {
                 off_t bytes;
                 uint64_t u;