diff --git a/man/org.freedesktop.systemd1.xml b/man/org.freedesktop.systemd1.xml
index d55f3c8f9bd..1edaf157b9e 100644
--- a/man/org.freedesktop.systemd1.xml
+++ b/man/org.freedesktop.systemd1.xml
@@ -2401,6 +2401,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -3504,6 +3506,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
+
+
@@ -4063,6 +4067,11 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
MountImages
ExtensionImages
see systemd.exec(5) for their meaning.
+
+ MemoryAvailable indicates how much unused memory is available to the unit before
+ the MemoryMax or MemoryHigh (whichever is lower) limit set by the cgroup
+ memory controller is reached. It will take into consideration limits on all parent slices, other than the
+ limits set on the unit itself.
@@ -4196,6 +4205,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -5321,6 +5332,8 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2esocket {
+
+
@@ -5915,6 +5928,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -6886,6 +6901,8 @@ node /org/freedesktop/systemd1/unit/home_2emount {
+
+
@@ -7601,6 +7618,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -8544,6 +8563,8 @@ node /org/freedesktop/systemd1/unit/dev_2dsda3_2eswap {
+
+
@@ -9112,6 +9133,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -9403,6 +9426,8 @@ node /org/freedesktop/systemd1/unit/system_2eslice {
+
+
@@ -9571,6 +9596,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t MemoryCurrent = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
+ readonly t MemoryAvailable = ...;
+ @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly t CPUUsageNSec = ...;
@org.freedesktop.DBus.Property.EmitsChangedSignal("false")
readonly ay EffectiveCPUs = [...];
@@ -9904,6 +9931,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
+
+
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 6a46e14556d..7fde1efce42 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -3402,6 +3402,77 @@ int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {
return 1;
}
+int unit_get_memory_available(Unit *u, uint64_t *ret) {
+ uint64_t unit_current, available = UINT64_MAX;
+ CGroupContext *unit_context;
+ const char *memory_file;
+ int r;
+
+ assert(u);
+ assert(ret);
+
+ /* If data from cgroups can be accessed, try to find out how much more memory a unit can
+ * claim before hitting the configured cgroup limits (if any). Consider both MemoryHigh
+ * and MemoryMax, and also any slice the unit might be nested below. */
+
+ if (!UNIT_CGROUP_BOOL(u, memory_accounting))
+ return -ENODATA;
+
+ if (!u->cgroup_path)
+ return -ENODATA;
+
+ /* The root cgroup doesn't expose this information */
+ if (unit_has_host_root_cgroup(u))
+ return -ENODATA;
+
+ if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0)
+ return -ENODATA;
+
+ r = cg_all_unified();
+ if (r < 0)
+ return r;
+ memory_file = r > 0 ? "memory.current" : "memory.usage_in_bytes";
+
+ r = cg_get_attribute_as_uint64("memory", u->cgroup_path, memory_file, &unit_current);
+ if (r < 0)
+ return r;
+
+ assert_se(unit_context = unit_get_cgroup_context(u));
+
+ if (unit_context->memory_max != UINT64_MAX || unit_context->memory_high != UINT64_MAX)
+ available = LESS_BY(MIN(unit_context->memory_max, unit_context->memory_high), unit_current);
+
+ for (Unit *slice = UNIT_GET_SLICE(u); slice; slice = UNIT_GET_SLICE(slice)) {
+ uint64_t slice_current, slice_available = UINT64_MAX;
+ CGroupContext *slice_context;
+
+ /* No point in continuing if we can't go any lower */
+ if (available == 0)
+ break;
+
+ if (!slice->cgroup_path)
+ continue;
+
+ slice_context = unit_get_cgroup_context(slice);
+ if (!slice_context)
+ continue;
+
+ if (slice_context->memory_max == UINT64_MAX && slice_context->memory_high == UINT64_MAX)
+ continue;
+
+ r = cg_get_attribute_as_uint64("memory", slice->cgroup_path, memory_file, &slice_current);
+ if (r < 0)
+ continue;
+
+ slice_available = LESS_BY(MIN(slice_context->memory_max, slice_context->memory_high), slice_current);
+ available = MIN(slice_available, available);
+ }
+
+ *ret = available;
+
+ return 0;
+}
+
int unit_get_memory_current(Unit *u, uint64_t *ret) {
int r;
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index 1ad5dd38389..e6790eb0e83 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -282,6 +282,7 @@ int unit_watch_all_pids(Unit *u);
int unit_synthesize_cgroup_empty_event(Unit *u);
int unit_get_memory_current(Unit *u, uint64_t *ret);
+int unit_get_memory_available(Unit *u, uint64_t *ret);
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);
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 6c04c6e5db8..aa10939a041 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -1097,6 +1097,30 @@ static int property_get_current_memory(
return sd_bus_message_append(reply, "t", sz);
}
+static int property_get_available_memory(
+ sd_bus *bus,
+ const char *path,
+ const char *interface,
+ const char *property,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *error) {
+
+ uint64_t sz = UINT64_MAX;
+ Unit *u = userdata;
+ int r;
+
+ assert(bus);
+ assert(reply);
+ assert(u);
+
+ r = unit_get_memory_available(u, &sz);
+ if (r < 0 && r != -ENODATA)
+ log_unit_warning_errno(u, r, "Failed to get total available memory from cgroup: %m");
+
+ return sd_bus_message_append(reply, "t", sz);
+}
+
static int property_get_current_tasks(
sd_bus *bus,
const char *path,
@@ -1541,6 +1565,7 @@ const sd_bus_vtable bus_unit_cgroup_vtable[] = {
SD_BUS_PROPERTY("Slice", "s", property_get_slice, 0, 0),
SD_BUS_PROPERTY("ControlGroup", "s", property_get_cgroup, 0, 0),
SD_BUS_PROPERTY("MemoryCurrent", "t", property_get_current_memory, 0, 0),
+ SD_BUS_PROPERTY("MemoryAvailable", "t", property_get_available_memory, 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),
diff --git a/src/shared/bus-print-properties.c b/src/shared/bus-print-properties.c
index cbd5fb087e0..b45921943a8 100644
--- a/src/shared/bus-print-properties.c
+++ b/src/shared/bus-print-properties.c
@@ -165,7 +165,7 @@ 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 ((STR_IN_SET(name, "DefaultMemoryLow", "DefaultMemoryMin", "MemoryLow", "MemoryHigh", "MemoryMax", "MemorySwapMax", "MemoryLimit") && u == CGROUP_LIMIT_MAX) ||
+ else if ((STR_IN_SET(name, "DefaultMemoryLow", "DefaultMemoryMin", "MemoryLow", "MemoryHigh", "MemoryMax", "MemorySwapMax", "MemoryLimit", "MemoryAvailable") && u == CGROUP_LIMIT_MAX) ||
(STR_IN_SET(name, "TasksMax", "DefaultTasksMax") && u == UINT64_MAX) ||
(startswith(name, "Limit") && u == UINT64_MAX) ||
(startswith(name, "DefaultLimit") && u == UINT64_MAX))
diff --git a/src/systemctl/systemctl-show.c b/src/systemctl/systemctl-show.c
index 3686ac3c768..d4d5a2b427f 100644
--- a/src/systemctl/systemctl-show.c
+++ b/src/systemctl/systemctl-show.c
@@ -247,6 +247,7 @@ typedef struct UnitStatusInfo {
uint64_t memory_max;
uint64_t memory_swap_max;
uint64_t memory_limit;
+ uint64_t memory_available;
uint64_t cpu_usage_nsec;
uint64_t tasks_current;
uint64_t tasks_max;
@@ -682,6 +683,7 @@ static void print_status_info(
if (i->memory_min > 0 || i->memory_low > 0 ||
i->memory_high != CGROUP_LIMIT_MAX || i->memory_max != CGROUP_LIMIT_MAX ||
i->memory_swap_max != CGROUP_LIMIT_MAX ||
+ i->memory_available != CGROUP_LIMIT_MAX ||
i->memory_limit != CGROUP_LIMIT_MAX) {
const char *prefix = "";
@@ -710,6 +712,10 @@ static void print_status_info(
printf("%slimit: %s", prefix, format_bytes(buf, sizeof(buf), i->memory_limit));
prefix = " ";
}
+ if (i->memory_available != CGROUP_LIMIT_MAX) {
+ printf("%savailable: %s", prefix, format_bytes(buf, sizeof(buf), i->memory_available));
+ prefix = " ";
+ }
printf(")");
}
printf("\n");
@@ -1827,6 +1833,7 @@ static int show_one(
{ "Where", "s", NULL, offsetof(UnitStatusInfo, where) },
{ "What", "s", NULL, offsetof(UnitStatusInfo, what) },
{ "MemoryCurrent", "t", NULL, offsetof(UnitStatusInfo, memory_current) },
+ { "MemoryAvailable", "t", NULL, offsetof(UnitStatusInfo, memory_available) },
{ "DefaultMemoryMin", "t", NULL, offsetof(UnitStatusInfo, default_memory_min) },
{ "DefaultMemoryLow", "t", NULL, offsetof(UnitStatusInfo, default_memory_low) },
{ "MemoryMin", "t", NULL, offsetof(UnitStatusInfo, memory_min) },
@@ -1869,6 +1876,7 @@ static int show_one(
.memory_max = CGROUP_LIMIT_MAX,
.memory_swap_max = CGROUP_LIMIT_MAX,
.memory_limit = UINT64_MAX,
+ .memory_available = CGROUP_LIMIT_MAX,
.cpu_usage_nsec = UINT64_MAX,
.tasks_current = UINT64_MAX,
.tasks_max = UINT64_MAX,