core: add MemoryMin

The kernel added support for a new cgroup memory controller knob memory.min in
bf8d5d52ffe8 ("memcg: introduce memory.min") which was merged during v4.18
merge window.

Add MemoryMin to support memory.min.

(cherry picked from commit 484226357789991de0b3363beb69258be06b4c92)

Resolves: #1763435

5 files changed, 16 insertions, 2 deletions

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index f8b351a65d..9d09c65453 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -220,6 +220,7 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                 "%sStartupIOWeight=%" PRIu64 "\n"
                 "%sBlockIOWeight=%" PRIu64 "\n"
                 "%sStartupBlockIOWeight=%" PRIu64 "\n"
+                "%sMemoryMin=%" PRIu64 "\n"
                 "%sMemoryLow=%" PRIu64 "\n"
                 "%sMemoryHigh=%" PRIu64 "\n"
                 "%sMemoryMax=%" PRIu64 "\n"
@@ -246,6 +247,7 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
                 prefix, c->startup_io_weight,
                 prefix, c->blockio_weight,
                 prefix, c->startup_blockio_weight,
+                prefix, c->memory_min,
                 prefix, c->memory_low,
                 prefix, c->memory_high,
                 prefix, c->memory_max,
@@ -777,7 +779,7 @@ static void cgroup_apply_blkio_device_limit(Unit *u, const char *dev_path, uint6
 }
 
 static bool cgroup_context_has_unified_memory_config(CGroupContext *c) {
-        return c->memory_low > 0 || c->memory_high != CGROUP_LIMIT_MAX || c->memory_max != CGROUP_LIMIT_MAX || c->memory_swap_max != CGROUP_LIMIT_MAX;
+        return c->memory_min > 0 || c->memory_low > 0 || c->memory_high != CGROUP_LIMIT_MAX || c->memory_max != CGROUP_LIMIT_MAX || c->memory_swap_max != CGROUP_LIMIT_MAX;
 }
 
 static void cgroup_apply_unified_memory_limit(Unit *u, const char *file, uint64_t v) {
@@ -1035,6 +1037,7 @@ static void cgroup_context_apply(
                                         log_cgroup_compat(u, "Applying MemoryLimit %" PRIu64 " as MemoryMax", max);
                         }
 
+                        cgroup_apply_unified_memory_limit(u, "memory.min", c->memory_min);
                         cgroup_apply_unified_memory_limit(u, "memory.low", c->memory_low);
                         cgroup_apply_unified_memory_limit(u, "memory.high", c->memory_high);
                         cgroup_apply_unified_memory_limit(u, "memory.max", max);
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index 2ba57d3ded..5e1be87b20 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -95,6 +95,7 @@ struct CGroupContext {
         LIST_HEAD(CGroupIODeviceLimit, io_device_limits);
         LIST_HEAD(CGroupIODeviceLatency, io_device_latencies);
 
+        uint64_t memory_min;
         uint64_t memory_low;
         uint64_t memory_high;
         uint64_t memory_max;
diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index 4555b33b1f..6ce5984a02 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -353,6 +353,7 @@ const sd_bus_vtable bus_cgroup_vtable[] = {
         SD_BUS_PROPERTY("BlockIOReadBandwidth", "a(st)", property_get_blockio_device_bandwidths, 0, 0),
         SD_BUS_PROPERTY("BlockIOWriteBandwidth", "a(st)", property_get_blockio_device_bandwidths, 0, 0),
         SD_BUS_PROPERTY("MemoryAccounting", "b", bus_property_get_bool, offsetof(CGroupContext, memory_accounting), 0),
+        SD_BUS_PROPERTY("MemoryMin", "t", NULL, offsetof(CGroupContext, memory_min), 0),
         SD_BUS_PROPERTY("MemoryLow", "t", NULL, offsetof(CGroupContext, memory_low), 0),
         SD_BUS_PROPERTY("MemoryHigh", "t", NULL, offsetof(CGroupContext, memory_high), 0),
         SD_BUS_PROPERTY("MemoryMax", "t", NULL, offsetof(CGroupContext, memory_max), 0),
@@ -661,6 +662,9 @@ int bus_cgroup_set_property(
         if (streq(name, "MemoryAccounting"))
                 return bus_cgroup_set_boolean(u, name, &c->memory_accounting, CGROUP_MASK_MEMORY, message, flags, error);
 
+        if (streq(name, "MemoryMin"))
+                return bus_cgroup_set_memory(u, name, &c->memory_min, message, flags, error);
+
         if (streq(name, "MemoryLow"))
                 return bus_cgroup_set_memory(u, name, &c->memory_low, message, flags, error);
 
@@ -676,6 +680,9 @@ int bus_cgroup_set_property(
         if (streq(name, "MemoryLimit"))
                 return bus_cgroup_set_memory(u, name, &c->memory_limit, message, flags, error);
 
+        if (streq(name, "MemoryMinScale"))
+                return bus_cgroup_set_memory_scale(u, name, &c->memory_min, message, flags, error);
+
         if (streq(name, "MemoryLowScale"))
                 return bus_cgroup_set_memory_scale(u, name, &c->memory_low, message, flags, error);
 
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 4defa82ac1..1c6e539f30 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -171,6 +171,7 @@ $1.StartupCPUShares,             config_parse_cpu_shares,            0,
 $1.CPUQuota,                     config_parse_cpu_quota,             0,                             offsetof($1, cgroup_context)
 $1.CPUQuotaPeriodSec,            config_parse_sec_def_infinity,      0,                             offsetof($1, cgroup_context.cpu_quota_period_usec)
 $1.MemoryAccounting,             config_parse_bool,                  0,                             offsetof($1, cgroup_context.memory_accounting)
+$1.MemoryMin,                    config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
 $1.MemoryLow,                    config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
 $1.MemoryHigh,                   config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
 $1.MemoryMax,                    config_parse_memory_limit,          0,                             offsetof($1, cgroup_context)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 762b106007..d43b0f08f9 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -3096,7 +3096,9 @@ int config_parse_memory_limit(
                 }
         }
 
-        if (streq(lvalue, "MemoryLow"))
+        if (streq(lvalue, "MemoryMin"))
+                c->memory_min = bytes;
+        else if (streq(lvalue, "MemoryLow"))
                 c->memory_low = bytes;
         else if (streq(lvalue, "MemoryHigh"))
                 c->memory_high = bytes;