UCX osc: atomic fetch-and-op only on 32 and 64bit values

Signed-off-by: Joseph Schuchart <schuchart@hlrs.de>

ompi/mca/osc/ucx/osc_ucx_comm.c

@@ -24,6 +24,11 @@
         return OMPI_ERROR;                                                       \
     }
 
+/* macro to check whether UCX supports atomic operation on the size the operands */
+#define ATOMIC_SIZE_SUPPORTED(_remote_addr, _size) \
+    ((sizeof(uint32_t) == (_size) && !((_remote_addr) & 0x3)) || \
+     (sizeof(uint64_t) == (_size) && !((_remote_addr) & 0x7)))
+
 typedef struct ucx_iovec {
     void *addr;
     size_t len;
@@ -367,6 +372,7 @@ static inline
 bool use_atomic_op(
     ompi_osc_ucx_module_t  *module,
     struct ompi_op_t       *op,
+    uint64_t                remote_addr,
     struct ompi_datatype_t *origin_dt,
     struct ompi_datatype_t *target_dt,
     int                     origin_count,
@@ -384,9 +390,8 @@ bool use_atomic_op(
         ompi_datatype_type_size(origin_dt, &origin_dt_bytes);
         ompi_datatype_type_size(target_dt, &target_dt_bytes);
         /* UCX only supports 32 and 64-bit operands atm */
-        if (sizeof(uint64_t) >= origin_dt_bytes &&
+        if (ATOMIC_SIZE_SUPPORTED(remote_addr, origin_dt_bytes) &&
-            sizeof(uint32_t) <= origin_dt_bytes &&
+            origin_dt_bytes  == target_dt_bytes    &&
-            origin_dt_bytes  == target_dt_bytes &&
             origin_count     == target_count) {
             return true;
         }
@@ -603,7 +608,7 @@ int accumulate_req(const void *origin_addr, int origin_count,
     }
 
     /* rely on UCX network atomics if the user told us that it safe */
-    if (use_atomic_op(module, op, origin_dt, target_dt, origin_count, target_count)) {
+    if (use_atomic_op(module, op, target_disp, origin_dt, target_dt, origin_count, target_count)) {
         return do_atomic_op_intrinsic(module, op, target,
                                       origin_addr, origin_count, origin_dt,
                                       target_disp, NULL, ucx_req);
@@ -775,7 +780,7 @@ int ompi_osc_ucx_compare_and_swap(const void *origin_addr, const void *compare_a
     }
 
     ompi_datatype_type_size(dt, &dt_bytes);
-    if (4 == dt_bytes || 8 == dt_bytes) {
+    if (ATOMIC_SIZE_SUPPORTED(remote_addr, dt_bytes)) {
         // fast path using UCX atomic operations
         return do_atomic_compare_and_swap(origin_addr, compare_addr,
                                           result_addr, dt, target,
@@ -818,6 +823,7 @@ int ompi_osc_ucx_fetch_and_op(const void *origin_addr, void *result_addr,
                               struct ompi_datatype_t *dt, int target,
                               ptrdiff_t target_disp, struct ompi_op_t *op,
                               struct ompi_win_t *win) {
+    size_t dt_bytes;
     ompi_osc_ucx_module_t *module = (ompi_osc_ucx_module_t*) win->w_osc_module;
     int ret = OMPI_SUCCESS;
 
@@ -826,12 +832,15 @@ int ompi_osc_ucx_fetch_and_op(const void *origin_addr, void *result_addr,
         return ret;
     }
 
-    if (op == &ompi_mpi_op_no_op.op || op == &ompi_mpi_op_replace.op ||
+    uint64_t remote_addr = (module->addrs[target]) + target_disp * OSC_UCX_GET_DISP(module, target);
-        op == &ompi_mpi_op_sum.op) {
+    ompi_datatype_type_size(dt, &dt_bytes);
+
+    /* UCX atomics are only supported on 32 and 64 bit values */
+    if (ATOMIC_SIZE_SUPPORTED(remote_addr, dt_bytes) &&
+        (op == &ompi_mpi_op_no_op.op || op == &ompi_mpi_op_replace.op ||
+         op == &ompi_mpi_op_sum.op)) {
         uint64_t value;
-        uint64_t remote_addr = (module->addrs[target]) + target_disp * OSC_UCX_GET_DISP(module, target);
         ucp_atomic_fetch_op_t opcode;
-        size_t dt_bytes;
         bool lock_acquired = false;
 
         if (!module->acc_single_intrinsic) {
@@ -894,7 +903,7 @@ int get_accumulate_req(const void *origin_addr, int origin_count,
     }
 
     /* rely on UCX network atomics if the user told us that it safe */
-    if (use_atomic_op(module, op, origin_dt, target_dt, origin_count, target_count)) {
+    if (use_atomic_op(module, op, target_disp, origin_dt, target_dt, origin_count, target_count)) {
         return do_atomic_op_intrinsic(module, op, target,
                                       origin_addr, origin_count, origin_dt,
                                       target_disp, result_addr, ucx_req);