diff -ur systemd-199.orig/src/udev/udevd.c systemd-199/src/udev/udevd.c
--- systemd-199.orig/src/udev/udevd.c	2013-03-25 22:28:30.593286782 +0200
+++ systemd-199/src/udev/udevd.c	2013-03-27 15:21:39.626748821 +0200
@@ -879,6 +879,29 @@
         fclose(f);
 }
 
+static int mem_size_mb(void)
+{
+        FILE *f;
+        char buf[4096];
+        long int memsize = -1;
+
+        f = fopen("/proc/meminfo", "re");
+        if (f == NULL)
+                return -1;
+
+        while (fgets(buf, sizeof(buf), f) != NULL) {
+                long int value;
+
+                if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
+                        memsize = value / 1024;
+                        break;
+                }
+        }
+
+        fclose(f);
+        return memsize;
+}
+
 static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
 {
         int ctrl = -1, netlink = -1;
@@ -1255,13 +1278,13 @@
         }
 
         if (children_max <= 0) {
-                cpu_set_t cpu_set;
+                int memsize = mem_size_mb();
 
-                children_max = 8;
-
-                if (sched_getaffinity(0, sizeof (cpu_set), &cpu_set) == 0) {
-                        children_max +=  CPU_COUNT(&cpu_set) * 2;
-                }
+                /* set value depending on the amount of RAM */
+                if (memsize > 0)
+                        children_max = 16 + (memsize / 8);
+                else
+                        children_max = 16;
         }
         log_debug("set children_max to %u\n", children_max);