systemctl: allow percent-based MemoryLimit= settings via systemctl set-property

The unit files already accept relative, percent-based memory limit
specification, let's make sure "systemctl set-property" support this too.

Since we want the physical memory size of the destination machine to apply we
pass the percentage in a new set of properties that only exist for this
purpose, and can only be set.

1 files changed, 52 insertions, 0 deletions

diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index fe035109e3..27bbe2d26d 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -856,6 +856,38 @@ int bus_cgroup_set_property(
 
                 return 1;
 
+        } else if (STR_IN_SET(name, "MemoryLowByPhysicalMemory", "MemoryHighByPhysicalMemory", "MemoryMaxByPhysicalMemory")) {
+                uint32_t raw;
+                uint64_t v;
+
+                r = sd_bus_message_read(message, "u", &raw);
+                if (r < 0)
+                        return r;
+
+                v = physical_memory_scale(raw, UINT32_MAX);
+                if (v <= 0 || v == UINT64_MAX)
+                        return sd_bus_error_set_errnof(error, EINVAL, "%s= is out of range", name);
+
+                if (mode != UNIT_CHECK) {
+                        const char *e;
+
+                        /* Chop off suffix */
+                        assert_se(e = endswith(name, "ByPhysicalMemory"));
+                        name = strndupa(name, e - name);
+
+                        if (streq(name, "MemoryLow"))
+                                c->memory_low = v;
+                        else if (streq(name, "MemoryHigh"))
+                                c->memory_high = v;
+                        else
+                                c->memory_max = v;
+
+                        unit_invalidate_cgroup(u, CGROUP_MASK_MEMORY);
+                        unit_write_drop_in_private_format(u, mode, name, "%s=%" PRIu32 "%%", name, (uint32_t) (DIV_ROUND_UP((uint64_t) raw * 100, (uint64_t) UINT32_MAX)));
+                }
+
+                return 1;
+
         } else if (streq(name, "MemoryLimit")) {
                 uint64_t limit;
 
@@ -877,6 +909,26 @@ int bus_cgroup_set_property(
 
                 return 1;
 
+        } else if (streq(name, "MemoryLimitByPhysicalMemory")) {
+                uint64_t limit;
+                uint32_t raw;
+
+                r = sd_bus_message_read(message, "u", &raw);
+                if (r < 0)
+                        return r;
+
+                limit = physical_memory_scale(raw, UINT32_MAX);
+                if (limit <= 0 || limit == UINT64_MAX)
+                        return sd_bus_error_set_errnof(error, EINVAL, "%s= is out of range", name);
+
+                if (mode != UNIT_CHECK) {
+                        c->memory_limit = limit;
+                        unit_invalidate_cgroup(u, CGROUP_MASK_MEMORY);
+                        unit_write_drop_in_private_format(u, mode, "MemoryLimit", "MemoryLimit=%" PRIu32 "%%", (uint32_t) (DIV_ROUND_UP((uint64_t) raw * 100, (uint64_t) UINT32_MAX)));
+                }
+
+                return 1;
+
         } else if (streq(name, "DevicePolicy")) {
                 const char *policy;
                 CGroupDevicePolicy p;