diff --git a/configure.ac b/configure.ac
index 5913b010e61..1533d244f9a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1383,7 +1383,6 @@ if test "$with_cross" != "no" ; then
 fi
 
 # This goes here because we need the top_srcdir
-HAVE_CXX_IO=0
 if test "$enable_romio" = "yes" ; then
    if test -d $use_top_srcdir/src/mpi/romio ; then
        AC_DEFINE(HAVE_ROMIO,1,[Define if ROMIO is enabled])
@@ -1403,10 +1402,9 @@ if test "$enable_romio" = "yes" ; then
        # This test used -e under Linux, but not all test programs understand
        # -e
        if test ! -d lib ; then mkdir lib ; fi
-       # tell mpi.h to include mpio.h
-       HAVE_ROMIO='#include "mpio.h"'
-       # tell mpicxx.h that we have IO
-       HAVE_CXX_IO=1
+       # define ROMIO_VERSION in mpi.h so application can check whether ROMIO is included
+       ROMIO_VERSION='#define ROMIO_VERSION 126'
+
        romio_subdir_args=""
        if test "$enable_mpi_abi" = "yes" ; then
            romio_subdir_args="--enable-mpi-abi"
@@ -1416,8 +1414,7 @@ if test "$enable_romio" = "yes" ; then
        AC_MSG_WARN([ROMIO src directory is not available])
    fi
 fi
-AC_SUBST(HAVE_ROMIO)
-AC_SUBST(HAVE_CXX_IO)
+AC_SUBST(ROMIO_VERSION)
 
 AM_CONDITIONAL([BUILD_ROMIO], [test x$enable_romio = xyes])
 #
@@ -3383,17 +3380,14 @@ AC_DEFINE_UNQUOTED([MPIR_OFFSET_MAX],[$MPIR_OFFSET_MAX],[limits.h _MAX constant
 MPI_OFFSET_TYPEDEF="typedef $MPI_OFFSET MPI_Offset;"
 AC_SUBST(MPI_OFFSET_TYPEDEF)
 #
-# Fortran type for an Offset type (needed to define MPI_DISPLACEMENT_CURRENT
-# The value for this comes from ROMIO, and is needed in mpif.h.in
+# Fortran type for an Offset type (needed to define MPI_DISPLACEMENT_CURRENT)
+# and is needed in mpif.h.in.
 # First, we check that this works with both Fortran compilers (if
 # they are defined)
 #
-# If there is no FORTRAN_MPI_OFFSET type (because ROMIO is disabled),
-# just use INTEGER
-if test -z "$FORTRAN_MPI_OFFSET" ; then
-    FORTRAN_MPI_OFFSET=INTEGER
-fi
 if test "$enable_f77" = yes -a "$enable_f90" = yes ; then
+    FORTRAN_MPI_OFFSET="INTEGER(KIND=$OFFSET_KIND)"
+
     AC_LANG_PUSH([Fortran 77])
     AC_MSG_CHECKING([whether the Fortran Offset type works with Fortran 77])
     AC_COMPILE_IFELSE([
diff --git a/maint/gen_binding_f08.py b/maint/gen_binding_f08.py
index 0af0904b764..4c91e5de28c 100644
--- a/maint/gen_binding_f08.py
+++ b/maint/gen_binding_f08.py
@@ -11,7 +11,7 @@
 import os
 
 def main():
-    # currently support -no-real128, -no-mpiio, -fint-size, -aint-size, -count-size, -cint-size
+    # currently support -no-real128, -fint-size, -aint-size, -count-size, -cint-size
     G.parse_cmdline()
 
     binding_dir = G.get_srcdir_path("src/binding")
diff --git a/maint/gen_binding_f77.py b/maint/gen_binding_f77.py
index dc56f779c31..0aed977ac24 100644
--- a/maint/gen_binding_f77.py
+++ b/maint/gen_binding_f77.py
@@ -11,7 +11,7 @@
 import os
 
 def main():
-    # currently support -no-real128, -no-mpiio, -aint-is-int
+    # currently support -no-real128, -aint-is-int
     G.parse_cmdline()
 
     binding_dir = G.get_srcdir_path("src/binding")
diff --git a/maint/local_python/binding_f08.py b/maint/local_python/binding_f08.py
index 64d1e12040b..e794650640c 100644
--- a/maint/local_python/binding_f08.py
+++ b/maint/local_python/binding_f08.py
@@ -1182,16 +1182,18 @@ def dump_handle_routines():
                     else:
                         G.out.append("    res = (f08%MPI_VAL /= f)")
                     G.out.append("END FUNCTION %s" % func_name)
-        # e.g. MPI_Comm_f2c
+
+    def dump_handle_f2c():
+        # e.g. MPI_Comm_f2c/c2f
+        G.out.append("INTERFACE")
+        G.out.append("INDENT")
         for a in G.handle_list:
-            if a == "MPI_File":
-                continue
             if RE.match(r'MPIX?_(\w+)', a):
                 c_name = "c_" + RE.m.group(1)
             for p in [("f", "c"), ("c", "f")]:
                 func_name = "%s_%s2%s" % (a, p[0], p[1])
                 G.out.append("")
-                G.out.append("FUNCTION %s(x) result(res)" % func_name)
+                G.out.append("FUNCTION %s(x) bind(C, name=\"P%s\") result(res)" % (func_name, func_name))
                 G.out.append("    USE mpi_c_interface_types, ONLY: %s" % c_name)
                 if p[0] == "f":
                     G.out.append("    INTEGER, VALUE :: x")
@@ -1199,25 +1201,7 @@ def dump_handle_routines():
                 else:
                     G.out.append("    INTEGER(%s), VALUE :: x" % c_name)
                     G.out.append("    INTEGER :: res")
-                G.out.append("    res = x")
                 G.out.append("END FUNCTION %s" % func_name)
-
-    def dump_file_interface():
-        G.out.append("")
-        G.out.append("INTERFACE")
-        G.out.append("INDENT")
-        for p in [("f", "c"), ("c", "f")]:
-            func_name = "MPI_File_%s2%s" % (p[0], p[1])
-            G.out.append("")
-            G.out.append("FUNCTION %s(x) bind(C, name=\"%s\") result(res)" % (func_name, func_name))
-            G.out.append("    USE mpi_c_interface_types, ONLY: c_File")
-            if p[0] == "f":
-                G.out.append("    INTEGER, VALUE :: x")
-                G.out.append("    INTEGER(c_File) :: res")
-            else:
-                G.out.append("    INTEGER(c_File), VALUE :: x")
-                G.out.append("    INTEGER :: res")
-            G.out.append("END FUNCTION MPI_File_%s2%s" % (p[0], p[1]))
         G.out.append("DEDENT")
         G.out.append("END INTERFACE")
 
@@ -1270,8 +1254,7 @@ def dump_sizeof_routines():
     G.out.append("")
     G.out.append("private :: c_int, c_Count, c_Status")
     dump_handle_types()
-    if "no-mpiio" not in G.opts:
-        dump_file_interface()
+    dump_handle_f2c()
     dump_status_type()
     dump_status_interface()
     dump_handle_interface()
diff --git a/maint/local_python/mpi_api.py b/maint/local_python/mpi_api.py
index 73c0364efe1..a0e8597efc9 100644
--- a/maint/local_python/mpi_api.py
+++ b/maint/local_python/mpi_api.py
@@ -245,71 +245,6 @@ def parse_param_attributes(p):
     else:
         p['asynchronous'] = False
 
-# FIXME: until ROMIO interface are generated
-def get_mpiio_func_list():
-    io_func_name_list = [
-        "MPI_File_c2f",
-        "MPI_File_close",
-        "MPI_File_delete",
-        "MPI_File_errhandler_function",
-        "MPI_File_f2c",
-        "MPI_File_get_amode",
-        "MPI_File_get_atomicity",
-        "MPI_File_get_byte_offset",
-        "MPI_File_get_group",
-        "MPI_File_get_info",
-        "MPI_File_get_position",
-        "MPI_File_get_position_shared",
-        "MPI_File_get_size",
-        "MPI_File_get_type_extent",
-        "MPI_File_get_view",
-        "MPI_File_iread",
-        "MPI_File_iread_all",
-        "MPI_File_iread_at",
-        "MPI_File_iread_at_all",
-        "MPI_File_iread_shared",
-        "MPI_File_iwrite",
-        "MPI_File_iwrite_all",
-        "MPI_File_iwrite_at",
-        "MPI_File_iwrite_at_all",
-        "MPI_File_iwrite_shared",
-        "MPI_File_open",
-        "MPI_File_preallocate",
-        "MPI_File_read",
-        "MPI_File_read_all",
-        "MPI_File_read_all_begin",
-        "MPI_File_read_all_end",
-        "MPI_File_read_at",
-        "MPI_File_read_at_all",
-        "MPI_File_read_at_all_begin",
-        "MPI_File_read_at_all_end",
-        "MPI_File_read_ordered",
-        "MPI_File_read_ordered_begin",
-        "MPI_File_read_ordered_end",
-        "MPI_File_read_shared",
-        "MPI_File_seek",
-        "MPI_File_seek_shared",
-        "MPI_File_set_atomicity",
-        "MPI_File_set_info",
-        "MPI_File_set_size",
-        "MPI_File_set_view",
-        "MPI_File_sync",
-        "MPI_File_write",
-        "MPI_File_write_all",
-        "MPI_File_write_all_begin",
-        "MPI_File_write_all_end",
-        "MPI_File_write_at",
-        "MPI_File_write_at_all",
-        "MPI_File_write_at_all_begin",
-        "MPI_File_write_at_all_end",
-        "MPI_File_write_ordered",
-        "MPI_File_write_ordered_begin",
-        "MPI_File_write_ordered_end",
-        "MPI_File_write_shared",
-        "MPI_Register_datarep"
-    ]
-    return [G.FUNCS[a.lower()] for a in io_func_name_list]
-
 def get_f77_dummy_func_list():
     dummy_func_name_list = [
         "MPI_DUP_FN",
diff --git a/src/binding/c/io_api.txt b/src/binding/c/io_api.txt
index 02d3257b74f..389d5cde9c6 100644
--- a/src/binding/c/io_api.txt
+++ b/src/binding/c/io_api.txt
@@ -111,6 +111,7 @@ MPI_File_read_at_all_begin:
 
 MPI_File_read_at_all_end:
     .desc: Complete a split collective read using
+    .skip: validate-buf
 
 MPI_File_read_all_begin:
     .desc: Begin a split collective read using individual file pointer
@@ -120,6 +121,7 @@ MPI_File_read_all:
 
 MPI_File_read_all_end:
     .desc: Complete a split collective read using
+    .skip: validate-buf
 
 MPI_File_read_at_all:
     .desc: Collective read using explicit offset
@@ -138,6 +140,7 @@ MPI_File_read_ordered:
 
 MPI_File_read_ordered_end:
     .desc: Complete a split collective read using shared file pointer
+    .skip: validate-buf
 
 MPI_File_read_shared:
     .desc: Read using shared file pointer
@@ -172,6 +175,7 @@ MPI_File_write_at_all_begin:
 
 MPI_File_write_at_all_end:
     .desc: Complete a split collective write using explicit offset
+    .skip: validate-buf
 
 MPI_File_write_all_begin:
     .desc: Begin a split collective write using
@@ -181,6 +185,7 @@ MPI_File_write_all:
 
 MPI_File_write_all_end:
     .desc: Complete a split collective write using individual file pointer
+    .skip: validate-buf
 
 MPI_File_write_at_all:
     .desc: Collective write using explicit offset
@@ -199,6 +204,7 @@ MPI_File_write_ordered:
 
 MPI_File_write_ordered_end:
     .desc: Complete a split collective write using shared file pointer
+    .skip: validate-buf
 
 MPI_File_write_shared:
     .desc: Write using shared file pointer
diff --git a/src/binding/cxx/buildiface b/src/binding/cxx/buildiface
index 83f4106235c..0f64b31f61b 100755
--- a/src/binding/cxx/buildiface
+++ b/src/binding/cxx/buildiface
@@ -1254,12 +1254,6 @@ typedef int MPI_File;\
     # Begin the class, writing the common operations (destructors etc.)
     &BeginClass( $class );
 
-    # Hack to ifdef out the file routines
-    if ($class eq "file") {
-	# Define the file type only if supported.
-	print $OUTFD "#if \@HAVE_CXX_IO\@\n";
-    }
-
     foreach $mpilevel (@mpilevels) {
 	if ($mpilevel eq "post") {
 	    $printed_extra_fnc = 1;
@@ -1307,11 +1301,6 @@ typedef int MPI_File;\
 	&$extrafnc( $OUTFD );
     }
 
-    # Hack to ifdef out the file routines
-    if ($class eq "file") {
-	# Define the file type only if supported.
-	print $OUTFD "#endif\n";
-    }
     &EndClass;
 
     # Special case.  Once we define a Datatype, add this typedef
@@ -1347,11 +1336,9 @@ typedef int MPI_File;\
     # Only define these typedefs when MPI-IO is available (this is the same
     # test as used for the rest of the I/O routines );
 print $OUTFD "\
-#if \@HAVE_CXX_IO\@
 typedef int Datarep_extent_function( const Datatype&, Aint&, void *);
 typedef int Datarep_conversion_function( void *, Datatype &, int, void *,
                 Offset, void * );
-#endif
 \n";
 
     print $OUTFD "\n";
@@ -1995,13 +1982,6 @@ extern Datatype TWOINTEGER;
 	else            { print $OUTFD ";\n"; }
     }
 
-    print $OUTFD "// Include these only if MPI-IO is available\n";
-    if ($giveValue) {
-        print $OUTFD "#ifdef HAVE_ROMIO\n";
-    } else {
-        print $OUTFD "#if \@HAVE_CXX_IO\@\n";
-    }
-
     # Other file constants
     foreach $int (MAX_DATAREP_STRING) {
         print $OUTFD "${extern}const int $int";
@@ -2021,7 +2001,6 @@ extern Datatype TWOINTEGER;
 	if ($giveValue) { print $OUTFD " = MPI_MODE_$int;\n"; }
 	else            { print $OUTFD ";\n"; }
     }
-    print $OUTFD "#endif // IO\n";
 
     # Some modes are for RMA, not I/O
     foreach $int (NOCHECK,NOPRECEDE, NOPUT, NOSTORE, NOSUCCEED) {
@@ -2654,7 +2633,6 @@ void Win::Call_errhandler( int errorcode ) const
     MPI_Win_call_errhandler( (MPI_Win) the_real_win, errorcode );
 }
 
-#ifdef HAVE_ROMIO
 void File::Call_errhandler( int errorcode ) const
 {
     // we must free the Errhandler object returned from Get_errhandler because
@@ -2671,7 +2649,6 @@ void File::Call_errhandler( int errorcode ) const
     }
     MPI_File_call_errhandler( (MPI_File) the_real_file, errorcode );
 }
-#endif // IO
 
 // Helper function to invoke the comm_world C++ error handler.
 void MPIR_Call_world_errhand( int err )
@@ -2685,7 +2662,6 @@ EOT
     # The data rep conversion functions need to be wrapped in C code
     # Only define this routine when MPI-IO is available (this is the same
     # test as used for the rest of the I/O routines );
-print $OUTFD "#ifdef HAVE_ROMIO\n";
     print $OUTFD "
 extern \"C\" {
 //
@@ -2747,7 +2723,6 @@ void Register_datarep( const char *datarep,
        routine for ldata will never be freed */
 }
 ";
-print $OUTFD "#endif\n";
 
 
     print $OUTFD "\
diff --git a/src/binding/cxx/user_proxy.inc b/src/binding/cxx/user_proxy.inc
index ab960ff0d20..f6be5b1abfc 100644
--- a/src/binding/cxx/user_proxy.inc
+++ b/src/binding/cxx/user_proxy.inc
@@ -32,9 +32,7 @@ struct CXX_errhan_state {
     union {
         MPI::Comm::Errhandler_function * comm_err_fn;
         MPI::Win::Errhandler_function * win_err_fn;
-#ifdef HAVE_ROMIO        
         MPI::File::Errhandler_function * file_err_fn;
-#endif
         // MPI::Session::Errhandler_function * session_err_fn;
     } u;
 };
@@ -60,14 +58,12 @@ static void CXX_win_errhan_proxy(MPI_Win win, int error_code, void *extra_state)
     p->u.win_err_fn(h, &error_code);
 }
 
-#ifdef HAVE_ROMIO        
 static void CXX_file_errhan_proxy(MPI_File file, int error_code, void *extra_state)
 {
     CXX_errhan_state *p = (CXX_errhan_state *) extra_state;
     MPI::File h = file;
     p->u.file_err_fn(h, &error_code);
 }
-#endif
 
 static void CXX_errhan_free(void *extra_state)
 {
@@ -100,7 +96,6 @@ Errhandler Win::Create_errhandler(MPI::Win::Errhandler_function *f)
     return e1;
 }
 
-#ifdef HAVE_ROMIO        
 Errhandler File::Create_errhandler(MPI::File::Errhandler_function *f)
 {
     CXX_errhan_state *p = new(CXX_errhan_state);
@@ -113,4 +108,3 @@ Errhandler File::Create_errhandler(MPI::File::Errhandler_function *f)
     e1.the_real_errhandler = eh;
     return e1;
 }
-#endif
diff --git a/src/include/mpi.h.in b/src/include/mpi.h.in
index 80b71af2ff2..da22ec56e92 100644
--- a/src/include/mpi.h.in
+++ b/src/include/mpi.h.in
@@ -43,6 +43,8 @@
 #define MPICH         1
 #define MPICH_HAS_C2F  1
 
+@ROMIO_VERSION@
+
 /* MPICH_VERSION is the version string. MPICH_NUMVERSION is the
  * numeric version that can be used in numeric comparisons.
  *
diff --git a/src/mpi/romio/Makefile.am b/src/mpi/romio/Makefile.am
index a6429766fd4..bb152a8f779 100644
--- a/src/mpi/romio/Makefile.am
+++ b/src/mpi/romio/Makefile.am
@@ -52,7 +52,9 @@ AM_CPPFLAGS += $(MPI_H_INCLUDE)
 # handle the "include" directory here
 AM_CPPFLAGS += -I$(top_builddir)/include -I$(top_srcdir)/include $(external_includes)
 # nodist_ b/c these are created by config.status and should not be distributed
+if INSTALL_HEADERS
 nodist_include_HEADERS += include/mpio.h include/mpiof.h
+endif
 
 # ------------------------------------------------------------------------
 
diff --git a/src/mpi/romio/configure.ac b/src/mpi/romio/configure.ac
index 6a42e3254d1..65f9fff2587 100644
--- a/src/mpi/romio/configure.ac
+++ b/src/mpi/romio/configure.ac
@@ -106,6 +106,7 @@ FROM_OMPI=${FROM_OMPI:-no}
 if test "$FROM_OMPI" = 1 ; then FROM_OMPI=yes ; fi
 
 AM_CONDITIONAL([BUILD_BINDING], [test "$FROM_MPICH" != "yes"])
+AM_CONDITIONAL([INSTALL_HEADERS], [test "$FROM_MPICH" != "yes"])
 
 # MPL
 AC_ARG_VAR([MPLLIBNAME],[can be used to override the name of the MPL library (default: "mpl")])
@@ -1556,10 +1557,6 @@ fi
 AC_SUBST(EXTRA_SRC_DIRS)
 AC_SUBST(FILE_SYS_DIRS)
 
-#
-CFLAGS="$CFLAGS -DHAVE_ROMIOCONF_H"
-#
-
 AC_MSG_NOTICE([setting SYSDEP_INC to $SYSDEP_INC])
 AC_SUBST(SYSDEP_INC)
 
diff --git a/test/mpi/Makefile_f77.mtest b/test/mpi/Makefile_f77.mtest
index 0282b49742b..126b0525110 100644
--- a/test/mpi/Makefile_f77.mtest
+++ b/test/mpi/Makefile_f77.mtest
@@ -15,7 +15,9 @@ AM_CPPFLAGS = -I$(top_builddir)/include -I$(top_srcdir)/include
 
 # This is right for many platforms, but not all.  The right fix involves a
 # configure test, but this version is no worse than the simplemake version was.
-AM_FFLAGS = -I.
+# Add -w to suppress all warnings. Compilers such as gfortrans warns even with
+# -fallow-argument-mismatch.
+AM_FFLAGS = -I. -w
 
 LDADD = $(top_builddir)/util/libmtest_f77.la
 mtest_c_objects = $(top_builddir)/util/libmtest_single.la
diff --git a/test/mpi/autogen.sh b/test/mpi/autogen.sh
index 0498768f75d..22d0d252492 100755
--- a/test/mpi/autogen.sh
+++ b/test/mpi/autogen.sh
@@ -64,7 +64,7 @@ check_copy() {
 
 generate_benchmarks() {
     MYDEF_BOOT=$PWD/../../modules/mydef_boot
-    if test -d $MYDEF_BOOT ; then
+    if test -d $MYDEF_BOOT/bin ; then
         echo "Generating benchmark tests"
         export PATH=$MYDEF_BOOT/bin:$PATH
         export PERL5LIB=$MYDEF_BOOT/lib/perl5
@@ -127,7 +127,6 @@ for dir in errors/f77/* ; do
 done
 echo "done"
 
-check_PYTHON
 $PYTHON maint/gen_all_mpitests.py
 
 echo "Running autoreconf in ."
diff --git a/test/mpi/configure.ac b/test/mpi/configure.ac
index 9a7ed7b50dc..24db03e3a1a 100644
--- a/test/mpi/configure.ac
+++ b/test/mpi/configure.ac
@@ -490,6 +490,13 @@ if test "$MPI_IS_MPICH" = "yes" ; then
             enable_threadcomm=no
         fi
 
+        # disable-romio
+        if test "$enable_romio" != "no" ; then
+            if grep 'disable-romio\|enable-romio=no' conftest.output > /dev/null ; then
+                enable_romio=no
+            fi
+        fi
+
         # enable_checkerrors
         if test "$enable_checkerrors" != "no" ; then
             if grep 'disable-error-checking\|enable-error-checking=no' conftest.output > /dev/null ; then
@@ -1565,11 +1572,6 @@ if test "$enable_cxx" = yes ; then
         AC_MSG_WARN([The compiler $CXX does not support C++ namespaces.  This may cause problems for the tests])
     fi
     AC_LANG_POP([C++])
-
-    dnl for util/mtest_cxx.cxx
-    if test "$mpi_io_works" = "yes" ; then
-        AC_DEFINE(HAVE_MPI_IO,1,[Define if MPI-IO (really ROMIO) is included])
-    fi
 fi
 
 AC_LANG_C
@@ -1591,6 +1593,9 @@ if test "$enable_romio" != no -a "$mpi_io_works" = yes ; then
     if test "$pac_cv_have_mpio_request" = no ; then
         AC_DEFINE(MPIO_USES_MPI_REQUEST,,[Define if MPI IO uses MPI_Request])
     fi
+
+    dnl for util/mtest_cxx.cxx, comm/cmsplit_type.c
+    AC_DEFINE(HAVE_MPI_IO,1,[Define if MPI-IO (really ROMIO) is included])
 fi
 AC_SUBST(iodir)
 
diff --git a/test/mpi/io/large_count.c b/test/mpi/io/large_count.c
index dedbdb79106..ccf046a7ed6 100644
--- a/test/mpi/io/large_count.c
+++ b/test/mpi/io/large_count.c
@@ -67,7 +67,7 @@ int main(int argc, char **argv)
         if (rank == 0) {
             printf("nprocs=%d NVARS=%d LEN=%d\n", nprocs, NVARS, LEN);
             printf("Expecting file size=%lld bytes (%.1f MB, %.1f GB)\n",
-                   fsize, (float) fsize / 1048576, (float) fsize / 1073741824);
+                   (long long) fsize, (float) fsize / 1048576, (float) fsize / 1073741824);
             printf("Each global variable is of size %d bytes (%.1f MB)\n",
                    gsize[0] * gsize[1], (float) gsize[0] * gsize[1] / 1048576);
             printf("Each process writes %zd bytes (%.1f MB, %.1f GB)\n",
diff --git a/test/mpi/io/large_dtype.c b/test/mpi/io/large_dtype.c
index 5ca4e0985bc..5f5722b0521 100644
--- a/test/mpi/io/large_dtype.c
+++ b/test/mpi/io/large_dtype.c
@@ -156,11 +156,12 @@ int main(int argc, char **argv)
             printf("Output file name = %s\n", filename);
             printf("nprocs=%d nvars=%d len=%d\n", nprocs, nvars, len);
             printf("Expecting file size=%lld bytes (%.1f MB, %.1f GB)\n",
-                   fsize * 2, (float) fsize * 2 / 1048576, (float) fsize * 2 / 1073741824);
-            printf("Each global variable is of size %d bytes (%.1f MB)\n",
-                   gsize[0] * gsize[1], (float) gsize[0] * gsize[1] / 1048576);
-            printf("Each process writes %zd bytes (%.1f MB, %.1f GB)\n",
-                   buf_len, (float) buf_len / 1048576, (float) buf_len / 1073741824);
+                   (long long) fsize * 2, (float) fsize * 2 / 1048576,
+                   (float) fsize * 2 / 1073741824);
+            printf("Each global variable is of size %d bytes (%.1f MB)\n", gsize[0] * gsize[1],
+                   (float) gsize[0] * gsize[1] / 1048576);
+            printf("Each process writes %zd bytes (%.1f MB, %.1f GB)\n", buf_len,
+                   (float) buf_len / 1048576, (float) buf_len / 1073741824);
             printf("** For nonblocking I/O test, the amount is twice\n");
             printf("-------------------------------------------------------\n");
         }