compile with glibc 2.2.17 and older

slabtop.c

@@ -11,7 +11,6 @@
 
 #include <stdlib.h>
 #include <stdio.h>
-#include <unistd.h>
 #include <string.h>
 #include <errno.h>
 #include <signal.h>
@@ -20,7 +19,11 @@
 #include <getopt.h>
 #include <ctype.h>
 #include <sys/ioctl.h>
+
 #include <sys/select.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 #include "proc/slab.h"
 #include "proc/version.h"