dnl for each function found we get a definition in config.h
dnl of the form HAVE_FUNCTION
-AC_CHECK_FUNCS(tzset mbstowcs opendir readdir chdir chroot getuid setlocale strerror strerror_r snprintf vsnprintf fpclass class fp_class isnan memmove strchr mktime getrusage gettimeofday posix_fadvise)
+AC_CHECK_FUNCS(tzset mbstowcs opendir readdir chdir chroot getuid setlocale strerror strerror_r snprintf vsnprintf fpclass class fp_class isnan memmove strchr mktime getrusage gettimeofday posix_fadvise madvise)
if test "x$enable_mmap" = xyes; then