v2.1.x: remove power7be configure block

NEWS

@@ -53,6 +53,17 @@ included in the vX.Y.Z section and be denoted as:
    (** also appeared: A.B.C)  -- indicating that this item was previously
                                  included in release version vA.B.C.
 
+2.1.4 -- TBD
+------------
+
+Bug fixes/minor improvements:
+- Disable the POWER 7/BE block in configure.  Note that POWER 7/BE is
+  still not a supported platform, but it is no longer automatically
+  disabled.  See
+  https://github.com/open-mpi/ompi/issues/4349#issuecomment-374970982
+  for more information.
+
+
 2.1.3 -- March, 2018
 --------------------
 

README

@@ -148,6 +148,15 @@ General notes
     using the clang-4.0 system compiler. A workaround is to build
     Open MPI using the GNU compiler.
 
+Platform Notes
+--------------
+
+- ARM and POWER users may experience intermittent hangs when Open MPI
+  is compiled with low optimization settings, due to an issue with our
+  atomic list implementation.  We recommend compiling with -O3
+  optimization, both for performance reasons and to avoid this hang.
+
+
 Compiler Notes
 --------------
 

configure.ac

@@ -82,17 +82,6 @@ AS_IF([test "$host" != "$target"],
       [AC_MSG_WARN([Cross-compile detected])
        AC_MSG_WARN([Cross-compiling is only partially supported])
        AC_MSG_WARN([Proceed at your own risk!])])
-# Check for architectures that we explicitly no longer support
-case "${host}" in
-    powerpc-*|powerpc64-*|ppc-*)
-        AC_MSG_ERROR([Big endian PPC is no longer supported.])
-        ;;
-esac
-case "${target}" in
-    powerpc-*|powerpc64-*|ppc-*)
-        AC_MSG_ERROR([Big endian PPC is no longer supported.])
-        ;;
-esac
 
 # AC_USE_SYSTEM_EXTENSIONS alters CFLAGS (e.g., adds -g -O2)
 OPAL_VAR_SCOPE_PUSH([CFLAGS_save])