osc/rdma: fix amo-based accumulate

This fixes an issue in osc/rdma when AMOs are used for accumulate operations
(vs get-accumulate). In this case a temporary buffer is needed to hold the
result of the operation (since fetching atomics are used). This buffer was
1) zero-sized, and 2) not freed. Both of these issues are fixed in this
commit. There was also an issue with unpacking due to using an uninitialized
convertor. The convertor is no longer passed in when no result is required.

Signed-off-by: Nathan Hjelm <[email protected]>

Author: hjelmn

ompi/mca/osc/rdma/osc_rdma_accumulate.c

@@ -260,16 +260,14 @@ static inline int ompi_osc_rdma_gacc_amo (ompi_osc_rdma_module_t *module, ompi_o
 {
     const bool use_amo = module->acc_use_amo;
     const size_t dt_size = datatype->super.size;
+    void *to_free = NULL;
     uint64_t offset = 0;
     int ret;
 
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_TRACE, "using network atomics for accumulate operation with count %d", count);
 
-    /* only one can be non-NULL */
-    assert (NULL == result || NULL == result_convertor);
-
-    if (NULL == result && NULL != result_convertor) {
-        result = malloc (request->len);
+    if (NULL == result) {
+        to_free = result = malloc (request->len);
         if (OPAL_UNLIKELY(NULL == result)) {
             return OMPI_ERR_OUT_OF_RESOURCE;
        }
@@ -316,6 +314,8 @@ static inline int ompi_osc_rdma_gacc_amo (ompi_osc_rdma_module_t *module, ompi_o
         ompi_osc_rdma_request_complete (request, MPI_SUCCESS);
     }
 
+    free (to_free);
+
     return OMPI_SUCCESS;
 }
 
@@ -331,6 +331,8 @@ static inline int ompi_osc_rdma_gacc_contig (ompi_osc_rdma_sync_t *sync, const v
     char *ptr = NULL;
     int ret;
 
+    request->len = target_datatype->super.size * module->network_amo_max_count;
+
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_TRACE, "initiating accumulate on contiguous region of %lu bytes to remote address %" PRIx64
                      ", sync %p", len, target_address, (void *) sync);
 
@@ -582,7 +584,7 @@ static inline int ompi_osc_rdma_gacc_master (ompi_osc_rdma_sync_t *sync, const v
                 }
 
                 ret = ompi_osc_rdma_gacc_contig (sync, source_iovec[source_iov_index].iov_base, acc_len / target_primitive->super.size,
-                                                 target_primitive, NULL, 0, NULL, &result_convertor, peer,
+                                                 target_primitive, NULL, 0, NULL, result_datatype ? &result_convertor : NULL, peer,
                                                  (uint64_t) (intptr_t) target_iovec[target_iov_index].iov_base, target_handle,
                                                  acc_len / target_primitive->super.size, target_primitive, op, subreq);
                 if (OPAL_UNLIKELY(OMPI_SUCCESS != ret)) {