UCP/WIREUP: Support reused lanes for EP reconfiguration

src/ucp/core/ucp_ep.c

@@ -1838,6 +1838,40 @@ ucp_lane_index_t ucp_ep_lookup_lane(ucp_ep_h ucp_ep, uct_ep_h uct_ep)
     return UCP_NULL_LANE;
 }
 
+ucp_lane_index_t ucp_ep_find_wireup_ep_lane(ucp_ep_h ep)
+{
+    ucp_lane_index_t lane;
+
+    for (lane = 0; lane < ucp_ep_num_lanes(ep); lane++) {
+        if (ucp_wireup_ep_test(ucp_ep_get_lane(ep, lane))) {
+            return lane;
+        }
+    }
+
+    return UCP_NULL_LANE;
+}
+
+ucp_lane_index_t
+ucp_ep_find_non_reused_lane(ucp_ep_h ep, const ucp_ep_config_key_t *key,
+                            const ucp_lane_index_t *reuse_lane_map)
+{
+    ucp_lane_map_t lane_bitmap = {0};
+    ucp_lane_index_t lane;
+
+    if (ucp_ep_has_cm_lane(ep)) {
+        return key->cm_lane;
+    }
+
+    for (lane = 0; lane < ucp_ep_num_lanes(ep); lane++) {
+        if (reuse_lane_map[lane] != UCP_NULL_LANE) {
+            lane_bitmap |= UCS_BIT(reuse_lane_map[lane]);
+        }
+    }
+
+    lane = ucs_ffs64_safe(~lane_bitmap);
+    return (lane < key->num_lanes) ? lane : UCP_NULL_LANE;
+}
+
 static int ucp_ep_lane_is_dst_index_match(ucp_rsc_index_t dst_index1,
                                           ucp_rsc_index_t dst_index2)
 {

src/ucp/core/ucp_ep.h

@@ -756,6 +756,12 @@ void ucp_ep_config_lanes_intersect(const ucp_ep_config_key_t *key1,
                                    const unsigned *addr_indices,
                                    ucp_lane_index_t *lane_map);
 
+ucp_lane_index_t
+ucp_ep_find_non_reused_lane(ucp_ep_h ep, const ucp_ep_config_key_t *key,
+                            const ucp_lane_index_t *reuse_lane_map);
+
+ucp_lane_index_t ucp_ep_find_wireup_ep_lane(ucp_ep_h ep);
+
 int ucp_ep_config_is_equal(const ucp_ep_config_key_t *key1,
                            const ucp_ep_config_key_t *key2);
 

src/ucp/wireup/wireup.c

@@ -1353,29 +1353,12 @@ static void ucp_wireup_discard_uct_eps(ucp_ep_h ep, uct_ep_h *uct_eps,
     }
 }
 
-
-
-static unsigned
-ucp_ep_num_reused_lanes(ucp_ep_h ep, const ucp_lane_index_t *reuse_lane_map)
-{
-    unsigned num_reused = 0;
-    ucp_lane_index_t lane;
-
-    for (lane = 0; lane < ucp_ep_num_lanes(ep); ++lane) {
-        num_reused += (reuse_lane_map[lane] != UCP_NULL_LANE);
-    }
-
-    return num_reused;
-}
-
 static int
 ucp_wireup_check_is_reconfigurable(ucp_ep_h ep,
                                    const ucp_ep_config_key_t *new_key,
                                    const ucp_unpacked_address_t *remote_address,
                                    const unsigned *addr_indices)
 {
-    ucp_lane_index_t reuse_lane_map[UCP_MAX_LANES];
-    const ucp_ep_config_key_t *old_key;
     ucp_lane_index_t lane;
 
     if ((ep->cfg_index == UCP_WORKER_CFG_INDEX_NULL) ||
@@ -1391,27 +1374,7 @@ ucp_wireup_check_is_reconfigurable(ucp_ep_h ep,
         }
     }
 
-    old_key = &ucp_ep_config(ep)->key;
-    ucp_ep_config_lanes_intersect(old_key, new_key, ep, remote_address,
-                                  addr_indices, reuse_lane_map);
-
-    /* For now, reconfig is supported only if no lanes are reused */
-    return ucp_ep_num_reused_lanes(ep, reuse_lane_map) == 0;
-}
-
-static ucp_lane_index_t
-ucp_wireup_find_non_reused_lane(ucp_ep_h ep, const ucp_ep_config_key_t *key,
-                                const ucp_lane_index_t *reuse_lane_map)
-{
-    if (ucp_ep_has_cm_lane(ep)) {
-        return key->cm_lane;
-    }
-
-    /* Just use first lane, as only non-reused lanes are allowed at the
-     * moment. */
-    ucs_assert(key->num_lanes > 0);
-    ucs_assert(ucp_ep_num_reused_lanes(ep, reuse_lane_map) == 0);
-    return 0;
+    return 1;
 }
 
 static ucs_status_t
@@ -1431,21 +1394,30 @@ ucp_wireup_replace_wireup_msg_lane(ucp_ep_h ep, ucp_ep_config_key_t *key,
     old_wireup_ep = ucp_wireup_ep(ucp_ep_get_lane(ep, old_lane));
     ucs_assert_always(old_wireup_ep != NULL);
 
+    /* Select CM/non-reused lane as new wireup lane */
+    new_wireup_lane = ucp_ep_find_non_reused_lane(ep, key, reuse_lane_map);
+
     /* Set wireup EP for new configuration's wireup lane */
     if (ucp_ep_has_cm_lane(ep)) {
         /* Use existing EP from CM lane */
         new_wireup_ep = ucp_ep_get_cm_wireup_ep(ep);
-        ucs_assert(new_wireup_ep != NULL);
-    } else {
+    } else if (new_wireup_lane != UCP_NULL_LANE) {
         /* Create new EP for non-CM flow */
         status = ucp_wireup_ep_create(ep, &uct_ep);
         if (status != UCS_OK) {
             return status;
         }
 
         new_wireup_ep = ucp_wireup_ep(uct_ep);
+    } else {
+        /* Use existing EP from selected wireup_ep */
+        new_wireup_lane = ucp_ep_find_wireup_ep_lane(ep);
+        ucs_assert(new_wireup_lane != UCP_NULL_LANE);
+        new_wireup_ep = ucp_wireup_ep(ucp_ep_get_lane(ep, new_wireup_lane));
     }
 
+    ucs_assert(new_wireup_ep != NULL);
+
     /* Get correct aux_rsc_index either from next_ep or aux_ep */
     aux_rsc_index = ucp_wireup_ep_is_next_ep_active(old_wireup_ep) ?
                             ucp_ep_get_rsc_index(ep, old_lane) :
@@ -1469,9 +1441,6 @@ ucp_wireup_replace_wireup_msg_lane(ucp_ep_h ep, ucp_ep_config_key_t *key,
     uct_ep_destroy(&old_wireup_ep->super.super);
     ucp_ep_set_lane(ep, old_lane, NULL);
 
-    /* Select CM/non-reused lane as new wireup lane */
-    new_wireup_lane = ucp_wireup_find_non_reused_lane(ep, key, reuse_lane_map);
-
     new_uct_eps[new_wireup_lane] = &new_wireup_ep->super.super;
     key->wireup_msg_lane         = new_wireup_lane;
     return UCS_OK;