delete backend o_direct if os != Linux

configure.ac

@@ -137,6 +137,10 @@ case "$target" in
 esac
 AM_CONDITIONAL([STARPU_HAVE_WINDOWS], [test "x$starpu_windows" = "xyes"])
 
+case ${target_os} in linux*)
+  AM_CONDITIONAL(STARPU_LINUX_SYS, test 1 = 1)
+esac
+
 # on Darwin, GCC targets i386 by default, so we don't have atomic ops
 AC_CHECK_SIZEOF([void *])
 SIZEOF_VOID_P=$ac_cv_sizeof_void_p

doc/doxygen/chapters/api/data_out_of_core.doxy

@@ -43,5 +43,6 @@ This set uses the unistd library (write, read...) to read/write on disk. <br />
 \ingroup API_Out_Of_Core
 This set uses the unistd library (write, read...) to read/write on disk with the O_DIRECT flag. <br />
 <strong>Warning: It creates one file per allocation !</strong>  <br />
+Only available on Linux.
 
 */

src/Makefile.am

@@ -159,7 +159,6 @@ libstarpu_@STARPU_EFFECTIVE_VERSION@_la_SOURCES = 						\
 	core/dependencies/tags.c				\
 	core/dependencies/task_deps.c				\
 	core/dependencies/data_concurrency.c			\
-	core/disk_ops/disk_unistd_o_direct.c			\
 	core/disk_ops/disk_stdio.c				\
 	core/disk_ops/disk_unistd.c                             \
 	core/disk_ops/unistd/disk_unistd_global.c		\
@@ -269,6 +268,11 @@ libstarpu_@STARPU_EFFECTIVE_VERSION@_la_SOURCES += drivers/scc/driver_scc_sink.c
 libstarpu_@STARPU_EFFECTIVE_VERSION@_la_SOURCES += drivers/scc/driver_scc_utils.c
 endif
 
+if STARPU_LINUX_SYS
+libstarpu_@STARPU_EFFECTIVE_VERSION@_la_SOURCES += core/disk_ops/disk_unistd_o_direct.c
+endif
+
+
 
 #########################################
 #										#