Fix description of the submit_readonly example

doc/doxygen/chapters/07data_management.doxy

@@ -230,7 +230,7 @@ And now we can submit tasks working on vert_handle handles (and not on the main
 handle any more). Eventually we want to work on the main handle again, so we
 submit the unpartitioning:
 
-starpu_data_unpartition_submit(handle, PARTS, vert_handle);
+starpu_data_unpartition_submit(handle, PARTS, vert_handle, -1);
 
 And now we can submit tasks working on the main handle again.
 
@@ -241,7 +241,9 @@ Planning several partitioning of the same data is also possible, one just has
 to submit unpartitioning (to get back to the initial handle) before submitting
 another partitioning.
 
-It is also possible to activate several partitioning at the same time, in read-only mode.
+It is also possible to activate several partitioning at the same time, in
+read-only mode, by using starpu_data_partition_readonly_submit.  A complete
+example is available in <c>examples/filters/fmultiple_submit_readonly.c</c>.
 
 \section ManualPartitioning Manual Partitioning
 

examples/filters/fmultiple_submit_readonly.c

@@ -17,10 +17,15 @@
 /*
  * This examplifies how to access the same matrix with different partitioned
  * views, doing the coherency through partition planning.
- * We first run a kernel on the whole matrix to fill it, then run a kernel on
- * each vertical slice to check the value,
- * and multiply it by two, then run a
- * kernel on each horizontal slice to do the same.
+ *
+ * We first run a kernel on the whole matrix to fill it, then check the value
+ * in parallel from the whole handle, from the horizontal slices, and from the
+ * vertical slices. Then we switch back to the whole matrix to check and scale
+ * it. Then we check the result again from the whole handle, the horizontal
+ * slices, and the vertical slices. Then we switch to read-write on the
+ * horizontal slices to check and scale them. Then we check again from the
+ * whole handle, the horizontal slices, and the vertical slices. Eventually we
+ * switch back to the whole matrix to check and scale it.
  */
 
 #include <starpu.h>