libnbc: fix iallgather[v]

In order to optimize for MPI_IN_PLACE, data is sent from the receive buffer. consequently, it should be sent with the receive type and count. Thanks Josh Hursey for the report and test case Refs open-mpi#2256 (back-ported from commit open-mpi/ompi@45336d0)
ggouaillardet · Oct 21, 2016 · cb1a229 · cb1a229
1 parent 373720f
commit cb1a229
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/ompi/mca/coll/libnbc/nbc_iallgather.c b/ompi/mca/coll/libnbc/nbc_iallgather.c
@@ -1,9 +1,11 @@
 /*
- * Copyright (c) 2006 The Trustees of Indiana University and Indiana
- *                    University Research and Technology
- *                    Corporation.  All rights reserved.
- * Copyright (c) 2006 The Technical University of Chemnitz. All 
- *                    rights reserved.
+ * Copyright (c) 2006      The Trustees of Indiana University and Indiana
+ *                         University Research and Technology
+ *                         Corporation.  All rights reserved.
+ * Copyright (c) 2006      The Technical University of Chemnitz. All 
+ *                         rights reserved.
+ * Copyright (c) 2016      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  *
  * Author(s): Torsten Hoefler <htor@cs.indiana.edu>
  *
@@ -98,7 +100,7 @@ int ompi_coll_libnbc_iallgather(void* sendbuf, int sendcount, MPI_Datatype sendt
         res = NBC_Sched_recv(rbuf, false, recvcount, recvtype, r, schedule);
         if (NBC_OK != res) { printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
         /* send to rank r - not from the sendbuf to optimize MPI_IN_PLACE */
-        res = NBC_Sched_send(sbuf, false, sendcount, sendtype, r, schedule);
+        res = NBC_Sched_send(sbuf, false, recvcount, recvtype, r, schedule);
         if (NBC_OK != res) { printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
       }
     }

diff --git a/ompi/mca/coll/libnbc/nbc_iallgatherv.c b/ompi/mca/coll/libnbc/nbc_iallgatherv.c
@@ -10,6 +10,8 @@
  * Copyright (c) 2012      Oracle and/or its affiliates.  All rights reserved.
  * Copyright (c) 2013      Los Alamos National Security, LLC. All rights
  *                         reserved.
+ * Copyright (c) 2016      Research Organization for Information Science
+ *                         and Technology (RIST). All rights reserved.
  *
  */
 #include "nbc_internal.h"
@@ -77,7 +79,8 @@ int ompi_coll_libnbc_iallgatherv(void* sendbuf, int sendcount, MPI_Datatype send
 
     res = NBC_Sched_recv(rbuf, false, recvcounts[rpeer], recvtype, rpeer, schedule);
     if (NBC_OK != res) { printf("Error in NBC_Sched_recv() (%i)\n", res); return res; }
-    res = NBC_Sched_send(sbuf, false, sendcount, sendtype, speer, schedule);
+    /* send to rank r - not from the sendbuf to optimize MPI_IN_PLACE */
+    res = NBC_Sched_send(sbuf, false, recvcounts[rank], recvtype, speer, schedule);
     if (NBC_OK != res) { printf("Error in NBC_Sched_send() (%i)\n", res); return res; }
   }