usnic: just add comments/explanations -- no code changes

opal/mca/btl/usnic/btl_usnic_frag.h

@@ -145,7 +145,7 @@ typedef struct {
 
 /**
  * Descriptor for a common segment.  This is exactly one packet and may
- * be send or receive
+ * be sent or received.
  */
 typedef struct opal_btl_usnic_segment_t {
     ompi_free_list_item_t us_list;
@@ -221,7 +221,7 @@ typedef struct opal_btl_usnic_frag_t {
     /* fragment descriptor type */
     opal_btl_usnic_frag_type_t uf_type;
 
-    /* utility segments */
+    /* utility segments (just seg_addr/seg_len) */
     mca_btl_base_segment_t uf_local_seg[2];
     mca_btl_base_segment_t uf_remote_seg[1];
 

opal/mca/btl/usnic/btl_usnic_recv.h

@@ -277,6 +277,10 @@ opal_btl_usnic_recv_fast(opal_btl_usnic_module_t *module,
 opal_output(0, "fast recv %d bytes:\n", bseg->us_btl_header->payload_len + sizeof(opal_btl_usnic_btl_header_t));
 opal_btl_usnic_dump_hex(bseg->us_btl_header, bseg->us_btl_header->payload_len + sizeof(opal_btl_usnic_btl_header_t));
 #endif
+    /* If this is a short incoming message (i.e., the message is
+       wholly contained in this one message -- it is not chunked
+       across multiple messages), and it's not a PUT from the sender,
+       then just handle it here. */
     if (endpoint != NULL && !endpoint->endpoint_exiting &&
             (OPAL_BTL_USNIC_PAYLOAD_TYPE_FRAG ==
                 bseg->us_btl_header->payload_type) &&
@@ -311,8 +315,10 @@ opal_btl_usnic_dump_hex(bseg->us_btl_header, bseg->us_btl_header->payload_len +
 
 drop:
         channel->chan_deferred_recv = seg;
+    }
 
-    } else {
+    /* Otherwise, handle all the other cases the "normal" way */
+    else {
         opal_btl_usnic_recv_call(module, seg, channel);
     }
 }
@@ -382,6 +388,10 @@ opal_btl_usnic_recv(opal_btl_usnic_module_t *module,
     endpoint = lookup_sender(module, bseg);
     seg->rs_endpoint = endpoint;
 
+    /* If this is a short incoming message (i.e., the message is
+       wholly contained in this one message -- it is not chunked
+       across multiple messages), and it's not a PUT from the sender,
+       then just handle it here. */
     if (endpoint != NULL && !endpoint->endpoint_exiting &&
             (OPAL_BTL_USNIC_PAYLOAD_TYPE_FRAG ==
                 bseg->us_btl_header->payload_type) &&
@@ -408,7 +418,10 @@ opal_btl_usnic_recv(opal_btl_usnic_module_t *module,
         reg->cbfunc(&module->super, bseg->us_btl_header->tag,
                     &seg->rs_desc, reg->cbdata);
 
-    } else {
+    }
+
+    /* Otherwise, handle all the other cases the "normal" way */
+    else {
         opal_btl_usnic_recv_call(module, seg, channel);
     }
 }

opal/mca/btl/usnic/btl_usnic_send.c

@@ -11,7 +11,7 @@
  *                         All rights reserved.
  * Copyright (c) 2006      Sandia National Laboratories. All rights
  *                         reserved.
- * Copyright (c) 2008-2014 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2008-2015 Cisco Systems, Inc.  All rights reserved.
  * Copyright (c) 2012      Los Alamos National Security, LLC.  All rights
  *                         reserved.
  * $COPYRIGHT$
@@ -106,7 +106,8 @@ opal_btl_usnic_chunk_send_complete(opal_btl_usnic_module_t *module,
  * This routine lives in this file to help prevent automatic inlining by the
  * compiler.
  *
- * The "tag" only applies to sends. */
+ * The "tag" only applies to sends.
+ */
 int
 opal_btl_usnic_finish_put_or_send(
     opal_btl_usnic_module_t *module,