Index: rrdtool/src/rrd_tool.c
===================================================================
--- rrdtool.orig/src/rrd_tool.c	2008-02-24 14:05:10.000000000 +0100
+++ rrdtool/src/rrd_tool.c	2008-02-24 14:24:37.000000000 +0100
@@ -4,6 +4,8 @@
  * rrd_tool.c  Startup wrapper
  *****************************************************************************/
 
+#include <unistd.h>
+
 #include "rrd_tool.h"
 #include "rrd_xport.h"
 
Index: rrdtool/src/rrd_update.c
===================================================================
--- rrdtool.orig/src/rrd_update.c	2008-02-24 14:05:10.000000000 +0100
+++ rrdtool/src/rrd_update.c	2008-02-24 14:28:33.000000000 +0100
@@ -432,7 +432,12 @@
 #ifdef USE_MADVISE
     /* when we use mmaping we tell the kernel the mmap equivalent
        of POSIX_FADV_RANDOM */
-    madvise(rrd_mmaped_file,rrd_filesize,MADV_RANDOM);
+#ifdef __USE_BSD
+      madvise(rrd_mmaped_file,rrd_filesize,MADV_RANDOM);
+#endif
+#ifdef __USE_XOPEN2K
+    posix_madvise(rrd_mmaped_file,rrd_filesize,MADV_RANDOM);
+#endif
 #endif
 #endif
     /* loop through the arguments. */