osc/rdma: rearrange accumulate code

This commit rearranges the accumulate code so that network AMOs can be
used in a larger number of potential situations. This commit adds a
new MCA variable: osc_rdma_network_max_amo. This variable controls the
maximum datatype count where AMOs will be used. The old default for
this support was count == 1. The new default is count == 32.

Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>

Author: hjelmn

ompi/mca/osc/rdma/osc_rdma.h

@@ -13,7 +13,9 @@
  * Copyright (c) 2010      Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2012-2013 Sandia National Laboratories.  All rights reserved.
  * Copyright (c) 2016-2018 Intel, Inc. All rights reserved.
- * Copyright (c) 2020      Google, LLC. All rights reserved.
+ * Copyright (c) 2019      Triad National Security, LLC. All rights
+ *                         reserved.
+ * Copyright (c) 2020-2021 Google, LLC. All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -106,6 +108,9 @@ struct ompi_osc_rdma_component_t {
 
     /** directory where to place backing files */
     char *backing_directory;
+
+    /** maximum count for network AMO usage */
+    unsigned long network_amo_max_count;
 };
 typedef struct ompi_osc_rdma_component_t ompi_osc_rdma_component_t;
 
@@ -160,6 +165,9 @@ struct ompi_osc_rdma_module_t {
     /** Local displacement unit. */
     int disp_unit;
 
+    /** maximum count for network AMO usage */
+    unsigned long network_amo_max_count;
+
     /** global leader */
     ompi_osc_rdma_peer_t *leader;