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LU-9480 lnet: add enhanced statistics
[fs/lustre-release.git] / lnet / lnet / lib-move.c
index d93d061..7309d43 100644 (file)
@@ -44,10 +44,105 @@ static int local_nid_dist_zero = 1;
 module_param(local_nid_dist_zero, int, 0444);
 MODULE_PARM_DESC(local_nid_dist_zero, "Reserved");
 
+static inline struct lnet_comm_count *
+get_stats_counts(struct lnet_element_stats *stats,
+                enum lnet_stats_type stats_type)
+{
+       switch (stats_type) {
+       case LNET_STATS_TYPE_SEND:
+               return &stats->el_send_stats;
+       case LNET_STATS_TYPE_RECV:
+               return &stats->el_recv_stats;
+       case LNET_STATS_TYPE_DROP:
+               return &stats->el_drop_stats;
+       default:
+               CERROR("Unknown stats type\n");
+       }
+
+       return NULL;
+}
+
+void lnet_incr_stats(struct lnet_element_stats *stats, lnet_msg_type_t msg_type,
+                    enum lnet_stats_type stats_type)
+{
+       struct lnet_comm_count *counts = get_stats_counts(stats, stats_type);
+       if (!counts)
+               return;
+
+       switch (msg_type) {
+       case LNET_MSG_ACK:
+               atomic_inc(&counts->co_ack_count);
+               break;
+       case LNET_MSG_PUT:
+               atomic_inc(&counts->co_put_count);
+               break;
+       case LNET_MSG_GET:
+               atomic_inc(&counts->co_get_count);
+               break;
+       case LNET_MSG_REPLY:
+               atomic_inc(&counts->co_reply_count);
+               break;
+       case LNET_MSG_HELLO:
+               atomic_inc(&counts->co_hello_count);
+               break;
+       default:
+               CERROR("There is a BUG in the code. Unknown message type\n");
+               break;
+       }
+}
+
+__u32 lnet_sum_stats(struct lnet_element_stats *stats,
+                    enum lnet_stats_type stats_type)
+{
+       struct lnet_comm_count *counts = get_stats_counts(stats, stats_type);
+       if (!counts)
+               return 0;
+
+       return (atomic_read(&counts->co_ack_count) +
+               atomic_read(&counts->co_put_count) +
+               atomic_read(&counts->co_get_count) +
+               atomic_read(&counts->co_reply_count) +
+               atomic_read(&counts->co_hello_count));
+}
+
+static inline void assign_stats(struct lnet_ioctl_comm_count *msg_stats,
+                               struct lnet_comm_count *counts)
+{
+       msg_stats->ico_get_count = atomic_read(&counts->co_get_count);
+       msg_stats->ico_put_count = atomic_read(&counts->co_put_count);
+       msg_stats->ico_reply_count = atomic_read(&counts->co_reply_count);
+       msg_stats->ico_ack_count = atomic_read(&counts->co_ack_count);
+       msg_stats->ico_hello_count = atomic_read(&counts->co_hello_count);
+}
+
+void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
+                             struct lnet_element_stats *stats)
+{
+       struct lnet_comm_count *counts;
+
+       LASSERT(msg_stats);
+       LASSERT(stats);
+
+       counts = get_stats_counts(stats, LNET_STATS_TYPE_SEND);
+       if (!counts)
+               return;
+       assign_stats(&msg_stats->im_send_stats, counts);
+
+       counts = get_stats_counts(stats, LNET_STATS_TYPE_RECV);
+       if (!counts)
+               return;
+       assign_stats(&msg_stats->im_recv_stats, counts);
+
+       counts = get_stats_counts(stats, LNET_STATS_TYPE_DROP);
+       if (!counts)
+               return;
+       assign_stats(&msg_stats->im_drop_stats, counts);
+}
+
 int
 lnet_fail_nid(lnet_nid_t nid, unsigned int threshold)
 {
-       lnet_test_peer_t *tp;
+       struct lnet_test_peer *tp;
        struct list_head *el;
        struct list_head *next;
        struct list_head  cull;
@@ -74,7 +169,7 @@ lnet_fail_nid(lnet_nid_t nid, unsigned int threshold)
        lnet_net_lock(0);
 
        list_for_each_safe(el, next, &the_lnet.ln_test_peers) {
-               tp = list_entry(el, lnet_test_peer_t, tp_list);
+               tp = list_entry(el, struct lnet_test_peer, tp_list);
 
                if (tp->tp_threshold == 0 ||    /* needs culling anyway */
                    nid == LNET_NID_ANY ||      /* removing all entries */
@@ -87,7 +182,7 @@ lnet_fail_nid(lnet_nid_t nid, unsigned int threshold)
        lnet_net_unlock(0);
 
        while (!list_empty(&cull)) {
-               tp = list_entry(cull.next, lnet_test_peer_t, tp_list);
+               tp = list_entry(cull.next, struct lnet_test_peer, tp_list);
 
                list_del(&tp->tp_list);
                LIBCFS_FREE(tp, sizeof(*tp));
@@ -98,7 +193,7 @@ lnet_fail_nid(lnet_nid_t nid, unsigned int threshold)
 static int
 fail_peer (lnet_nid_t nid, int outgoing)
 {
-       lnet_test_peer_t *tp;
+       struct lnet_test_peer *tp;
        struct list_head *el;
        struct list_head *next;
        struct list_head  cull;
@@ -110,7 +205,7 @@ fail_peer (lnet_nid_t nid, int outgoing)
        lnet_net_lock(0);
 
        list_for_each_safe(el, next, &the_lnet.ln_test_peers) {
-               tp = list_entry(el, lnet_test_peer_t, tp_list);
+               tp = list_entry(el, struct lnet_test_peer, tp_list);
 
                if (tp->tp_threshold == 0) {
                        /* zombie entry */
@@ -144,7 +239,7 @@ fail_peer (lnet_nid_t nid, int outgoing)
        lnet_net_unlock(0);
 
        while (!list_empty(&cull)) {
-               tp = list_entry(cull.next, lnet_test_peer_t, tp_list);
+               tp = list_entry(cull.next, struct lnet_test_peer, tp_list);
                list_del(&tp->tp_list);
 
                LIBCFS_FREE(tp, sizeof(*tp));
@@ -558,8 +653,9 @@ lnet_extract_kiov(int dst_niov, lnet_kiov_t *dst,
 EXPORT_SYMBOL(lnet_extract_kiov);
 
 void
-lnet_ni_recv(lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
-            unsigned int offset, unsigned int mlen, unsigned int rlen)
+lnet_ni_recv(struct lnet_ni *ni, void *private, struct lnet_msg *msg,
+            int delayed, unsigned int offset, unsigned int mlen,
+            unsigned int rlen)
 {
        unsigned int  niov = 0;
        struct kvec *iov = NULL;
@@ -584,21 +680,22 @@ lnet_ni_recv(lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
                        iov  = msg->msg_iov;
                        kiov = msg->msg_kiov;
 
-                       LASSERT(niov > 0);
-                       LASSERT((iov == NULL) != (kiov == NULL));
+                       LASSERT (niov > 0);
+                       LASSERT ((iov == NULL) != (kiov == NULL));
                }
        }
 
-       rc = (ni->ni_lnd->lnd_recv)(ni, private, msg, delayed,
-                                   niov, iov, kiov, offset, mlen, rlen);
+       rc = (ni->ni_net->net_lnd->lnd_recv)(ni, private, msg, delayed,
+                                            niov, iov, kiov, offset, mlen,
+                                            rlen);
        if (rc < 0)
-               lnet_finalize(ni, msg, rc);
+               lnet_finalize(msg, rc);
 }
 
 static void
-lnet_setpayloadbuffer(lnet_msg_t *msg)
+lnet_setpayloadbuffer(struct lnet_msg *msg)
 {
-       lnet_libmd_t *md = msg->msg_md;
+       struct lnet_libmd *md = msg->msg_md;
 
        LASSERT(msg->msg_len > 0);
        LASSERT(!msg->msg_routing);
@@ -615,7 +712,7 @@ lnet_setpayloadbuffer(lnet_msg_t *msg)
 }
 
 void
-lnet_prep_send(lnet_msg_t *msg, int type, lnet_process_id_t target,
+lnet_prep_send(struct lnet_msg *msg, int type, struct lnet_process_id target,
               unsigned int offset, unsigned int len)
 {
        msg->msg_type = type;
@@ -626,17 +723,18 @@ lnet_prep_send(lnet_msg_t *msg, int type, lnet_process_id_t target,
        if (len != 0)
                lnet_setpayloadbuffer(msg);
 
-       memset(&msg->msg_hdr, 0, sizeof(msg->msg_hdr));
-       msg->msg_hdr.type           = cpu_to_le32(type);
-       msg->msg_hdr.dest_nid       = cpu_to_le64(target.nid);
-       msg->msg_hdr.dest_pid       = cpu_to_le32(target.pid);
+       memset (&msg->msg_hdr, 0, sizeof (msg->msg_hdr));
+       msg->msg_hdr.type           = cpu_to_le32(type);
+       /* dest_nid will be overwritten by lnet_select_pathway() */
+       msg->msg_hdr.dest_nid       = cpu_to_le64(target.nid);
+       msg->msg_hdr.dest_pid       = cpu_to_le32(target.pid);
        /* src_nid will be set later */
-       msg->msg_hdr.src_pid        = cpu_to_le32(the_lnet.ln_pid);
+       msg->msg_hdr.src_pid        = cpu_to_le32(the_lnet.ln_pid);
        msg->msg_hdr.payload_length = cpu_to_le32(len);
 }
 
 static void
-lnet_ni_send(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_ni_send(struct lnet_ni *ni, struct lnet_msg *msg)
 {
        void   *priv = msg->msg_private;
        int     rc;
@@ -645,28 +743,28 @@ lnet_ni_send(lnet_ni_t *ni, lnet_msg_t *msg)
        LASSERT (LNET_NETTYP(LNET_NIDNET(ni->ni_nid)) == LOLND ||
                 (msg->msg_txcredit && msg->msg_peertxcredit));
 
-       rc = (ni->ni_lnd->lnd_send)(ni, priv, msg);
+       rc = (ni->ni_net->net_lnd->lnd_send)(ni, priv, msg);
        if (rc < 0)
-               lnet_finalize(ni, msg, rc);
+               lnet_finalize(msg, rc);
 }
 
 static int
-lnet_ni_eager_recv(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_ni_eager_recv(struct lnet_ni *ni, struct lnet_msg *msg)
 {
        int     rc;
 
        LASSERT(!msg->msg_sending);
        LASSERT(msg->msg_receiving);
        LASSERT(!msg->msg_rx_ready_delay);
-       LASSERT(ni->ni_lnd->lnd_eager_recv != NULL);
+       LASSERT(ni->ni_net->net_lnd->lnd_eager_recv != NULL);
 
        msg->msg_rx_ready_delay = 1;
-       rc = (ni->ni_lnd->lnd_eager_recv)(ni, msg->msg_private, msg,
-                                         &msg->msg_private);
+       rc = (ni->ni_net->net_lnd->lnd_eager_recv)(ni, msg->msg_private, msg,
+                                                 &msg->msg_private);
        if (rc != 0) {
                CERROR("recv from %s / send to %s aborted: "
                       "eager_recv failed %d\n",
-                      libcfs_nid2str(msg->msg_rxpeer->lp_nid),
+                      libcfs_nid2str(msg->msg_rxpeer->lpni_nid),
                       libcfs_id2str(msg->msg_target), rc);
                LASSERT(rc < 0); /* required by my callers */
        }
@@ -674,52 +772,71 @@ lnet_ni_eager_recv(lnet_ni_t *ni, lnet_msg_t *msg)
        return rc;
 }
 
-/* NB: caller shall hold a ref on 'lp' as I'd drop lnet_net_lock */
+/*
+ * This function can be called from two paths:
+ *     1. when sending a message
+ *     2. when decommiting a message (lnet_msg_decommit_tx())
+ * In both these cases the peer_ni should have it's reference count
+ * acquired by the caller and therefore it is safe to drop the spin
+ * lock before calling lnd_query()
+ */
 static void
-lnet_ni_query_locked(lnet_ni_t *ni, lnet_peer_t *lp)
+lnet_ni_query_locked(struct lnet_ni *ni, struct lnet_peer_ni *lp)
 {
        cfs_time_t last_alive = 0;
+       int cpt = lnet_cpt_of_nid_locked(lp->lpni_nid, ni);
 
        LASSERT(lnet_peer_aliveness_enabled(lp));
-       LASSERT(ni->ni_lnd->lnd_query != NULL);
+       LASSERT(ni->ni_net->net_lnd->lnd_query != NULL);
 
-       lnet_net_unlock(lp->lp_cpt);
-       (ni->ni_lnd->lnd_query)(ni, lp->lp_nid, &last_alive);
-       lnet_net_lock(lp->lp_cpt);
+       lnet_net_unlock(cpt);
+       (ni->ni_net->net_lnd->lnd_query)(ni, lp->lpni_nid, &last_alive);
+       lnet_net_lock(cpt);
 
-       lp->lp_last_query = cfs_time_current();
+       lp->lpni_last_query = cfs_time_current();
 
        if (last_alive != 0) /* NI has updated timestamp */
-               lp->lp_last_alive = last_alive;
+               lp->lpni_last_alive = last_alive;
 }
 
 /* NB: always called with lnet_net_lock held */
 static inline int
-lnet_peer_is_alive (lnet_peer_t *lp, cfs_time_t now)
+lnet_peer_is_alive (struct lnet_peer_ni *lp, cfs_time_t now)
 {
-       int        alive;
+       int        alive;
        cfs_time_t deadline;
 
-       LASSERT(lnet_peer_aliveness_enabled(lp));
+       LASSERT (lnet_peer_aliveness_enabled(lp));
 
-       /* Trust lnet_notify() if it has more recent aliveness news, but
+       /*
+        * Trust lnet_notify() if it has more recent aliveness news, but
         * ignore the initial assumed death (see lnet_peers_start_down()).
         */
-       if (!lp->lp_alive && lp->lp_alive_count > 0 &&
-           cfs_time_aftereq(lp->lp_timestamp, lp->lp_last_alive))
+       spin_lock(&lp->lpni_lock);
+       if (!lp->lpni_alive && lp->lpni_alive_count > 0 &&
+           cfs_time_aftereq(lp->lpni_timestamp, lp->lpni_last_alive)) {
+               spin_unlock(&lp->lpni_lock);
                return 0;
+       }
 
-       deadline = cfs_time_add(lp->lp_last_alive,
-                               cfs_time_seconds(lp->lp_ni->ni_peertimeout));
+       deadline =
+         cfs_time_add(lp->lpni_last_alive,
+                      cfs_time_seconds(lp->lpni_net->net_tunables.
+                                       lct_peer_timeout));
        alive = cfs_time_after(deadline, now);
 
-       /* Update obsolete lp_alive except for routers assumed to be dead
+       /*
+        * Update obsolete lp_alive except for routers assumed to be dead
         * initially, because router checker would update aliveness in this
-        * case, and moreover lp_last_alive at peer creation is assumed.
+        * case, and moreover lpni_last_alive at peer creation is assumed.
         */
-       if (alive && !lp->lp_alive &&
-           !(lnet_isrouter(lp) && lp->lp_alive_count == 0))
-               lnet_notify_locked(lp, 0, 1, lp->lp_last_alive);
+       if (alive && !lp->lpni_alive &&
+           !(lnet_isrouter(lp) && lp->lpni_alive_count == 0)) {
+               spin_unlock(&lp->lpni_lock);
+               lnet_notify_locked(lp, 0, 1, lp->lpni_last_alive);
+       } else {
+               spin_unlock(&lp->lpni_lock);
+       }
 
        return alive;
 }
@@ -728,7 +845,7 @@ lnet_peer_is_alive (lnet_peer_t *lp, cfs_time_t now)
 /* NB: returns 1 when alive, 0 when dead, negative when error;
  *     may drop the lnet_net_lock */
 static int
-lnet_peer_alive_locked (lnet_peer_t *lp)
+lnet_peer_alive_locked (struct lnet_ni *ni, struct lnet_peer_ni *lp)
 {
        cfs_time_t now = cfs_time_current();
 
@@ -738,34 +855,36 @@ lnet_peer_alive_locked (lnet_peer_t *lp)
        if (lnet_peer_is_alive(lp, now))
                return 1;
 
-       /* Peer appears dead, but we should avoid frequent NI queries (at
-        * most once per lnet_queryinterval seconds). */
-       if (lp->lp_last_query != 0) {
+       /*
+        * Peer appears dead, but we should avoid frequent NI queries (at
+        * most once per lnet_queryinterval seconds).
+        */
+       if (lp->lpni_last_query != 0) {
                static const int lnet_queryinterval = 1;
 
                cfs_time_t next_query =
-                          cfs_time_add(lp->lp_last_query,
+                          cfs_time_add(lp->lpni_last_query,
                                        cfs_time_seconds(lnet_queryinterval));
 
                if (cfs_time_before(now, next_query)) {
-                       if (lp->lp_alive)
+                       if (lp->lpni_alive)
                                CWARN("Unexpected aliveness of peer %s: "
                                      "%d < %d (%d/%d)\n",
-                                     libcfs_nid2str(lp->lp_nid),
+                                     libcfs_nid2str(lp->lpni_nid),
                                      (int)now, (int)next_query,
                                      lnet_queryinterval,
-                                     lp->lp_ni->ni_peertimeout);
+                                     lp->lpni_net->net_tunables.lct_peer_timeout);
                        return 0;
                }
        }
 
        /* query NI for latest aliveness news */
-       lnet_ni_query_locked(lp->lp_ni, lp);
+       lnet_ni_query_locked(ni, lp);
 
        if (lnet_peer_is_alive(lp, now))
                return 1;
 
-       lnet_notify_locked(lp, 0, 0, lp->lp_last_alive);
+       lnet_notify_locked(lp, 0, 0, lp->lpni_last_alive);
        return 0;
 }
 
@@ -781,10 +900,10 @@ lnet_peer_alive_locked (lnet_peer_t *lp)
  * \retval -ECANCELED If the MD of the message has been unlinked.
  */
 static int
-lnet_post_send_locked(lnet_msg_t *msg, int do_send)
+lnet_post_send_locked(struct lnet_msg *msg, int do_send)
 {
-       lnet_peer_t             *lp = msg->msg_txpeer;
-       lnet_ni_t               *ni = lp->lp_ni;
+       struct lnet_peer_ni     *lp = msg->msg_txpeer;
+       struct lnet_ni          *ni = msg->msg_txni;
        int                     cpt = msg->msg_tx_cpt;
        struct lnet_tx_queue    *tq = ni->ni_tx_queues[cpt];
 
@@ -795,15 +914,23 @@ lnet_post_send_locked(lnet_msg_t *msg, int do_send)
 
        /* NB 'lp' is always the next hop */
        if ((msg->msg_target.pid & LNET_PID_USERFLAG) == 0 &&
-           lnet_peer_alive_locked(lp) == 0) {
+           lnet_peer_alive_locked(ni, lp) == 0) {
                the_lnet.ln_counters[cpt]->drop_count++;
                the_lnet.ln_counters[cpt]->drop_length += msg->msg_len;
                lnet_net_unlock(cpt);
+               if (msg->msg_txpeer)
+                       lnet_incr_stats(&msg->msg_txpeer->lpni_stats,
+                                       msg->msg_type,
+                                       LNET_STATS_TYPE_DROP);
+               if (msg->msg_txni)
+                       lnet_incr_stats(&msg->msg_txni->ni_stats,
+                                       msg->msg_type,
+                                       LNET_STATS_TYPE_DROP);
 
                CNETERR("Dropping message for %s: peer not alive\n",
                        libcfs_id2str(msg->msg_target));
                if (do_send)
-                       lnet_finalize(ni, msg, -EHOSTUNREACH);
+                       lnet_finalize(msg, -EHOSTUNREACH);
 
                lnet_net_lock(cpt);
                return -EHOSTUNREACH;
@@ -817,28 +944,31 @@ lnet_post_send_locked(lnet_msg_t *msg, int do_send)
                        "called on the MD/ME.\n",
                        libcfs_id2str(msg->msg_target));
                if (do_send)
-                       lnet_finalize(ni, msg, -ECANCELED);
+                       lnet_finalize(msg, -ECANCELED);
 
                lnet_net_lock(cpt);
                return -ECANCELED;
        }
 
        if (!msg->msg_peertxcredit) {
-               LASSERT((lp->lp_txcredits < 0) ==
-                       !list_empty(&lp->lp_txq));
+               spin_lock(&lp->lpni_lock);
+               LASSERT((lp->lpni_txcredits < 0) ==
+                       !list_empty(&lp->lpni_txq));
 
                msg->msg_peertxcredit = 1;
-               lp->lp_txqnob += msg->msg_len + sizeof(lnet_hdr_t);
-               lp->lp_txcredits--;
+               lp->lpni_txqnob += msg->msg_len + sizeof(struct lnet_hdr);
+               lp->lpni_txcredits--;
 
-               if (lp->lp_txcredits < lp->lp_mintxcredits)
-                       lp->lp_mintxcredits = lp->lp_txcredits;
+               if (lp->lpni_txcredits < lp->lpni_mintxcredits)
+                       lp->lpni_mintxcredits = lp->lpni_txcredits;
 
-               if (lp->lp_txcredits < 0) {
+               if (lp->lpni_txcredits < 0) {
                        msg->msg_tx_delayed = 1;
-                       list_add_tail(&msg->msg_list, &lp->lp_txq);
+                       list_add_tail(&msg->msg_list, &lp->lpni_txq);
+                       spin_unlock(&lp->lpni_lock);
                        return LNET_CREDIT_WAIT;
                }
+               spin_unlock(&lp->lpni_lock);
        }
 
        if (!msg->msg_txcredit) {
@@ -847,6 +977,7 @@ lnet_post_send_locked(lnet_msg_t *msg, int do_send)
 
                msg->msg_txcredit = 1;
                tq->tq_credits--;
+               atomic_dec(&ni->ni_tx_credits);
 
                if (tq->tq_credits < tq->tq_credits_min)
                        tq->tq_credits_min = tq->tq_credits;
@@ -867,10 +998,10 @@ lnet_post_send_locked(lnet_msg_t *msg, int do_send)
 }
 
 
-static lnet_rtrbufpool_t *
-lnet_msg2bufpool(lnet_msg_t *msg)
+static struct lnet_rtrbufpool *
+lnet_msg2bufpool(struct lnet_msg *msg)
 {
-       lnet_rtrbufpool_t       *rbp;
+       struct lnet_rtrbufpool  *rbp;
        int                     cpt;
 
        LASSERT(msg->msg_rx_committed);
@@ -888,42 +1019,45 @@ lnet_msg2bufpool(lnet_msg_t *msg)
 }
 
 static int
-lnet_post_routed_recv_locked (lnet_msg_t *msg, int do_recv)
+lnet_post_routed_recv_locked(struct lnet_msg *msg, int do_recv)
 {
        /* lnet_parse is going to lnet_net_unlock immediately after this, so it
         * sets do_recv FALSE and I don't do the unlock/send/lock bit.
         * I return LNET_CREDIT_WAIT if msg blocked and LNET_CREDIT_OK if
         * received or OK to receive */
-       lnet_peer_t         *lp = msg->msg_rxpeer;
-       lnet_rtrbufpool_t   *rbp;
-       lnet_rtrbuf_t       *rb;
+       struct lnet_peer_ni *lp = msg->msg_rxpeer;
+       struct lnet_rtrbufpool *rbp;
+       struct lnet_rtrbuf *rb;
 
-       LASSERT(msg->msg_iov == NULL);
-       LASSERT(msg->msg_kiov == NULL);
-       LASSERT(msg->msg_niov == 0);
-       LASSERT(msg->msg_routing);
-       LASSERT(msg->msg_receiving);
-       LASSERT(!msg->msg_sending);
+       LASSERT (msg->msg_iov == NULL);
+       LASSERT (msg->msg_kiov == NULL);
+       LASSERT (msg->msg_niov == 0);
+       LASSERT (msg->msg_routing);
+       LASSERT (msg->msg_receiving);
+       LASSERT (!msg->msg_sending);
 
        /* non-lnet_parse callers only receive delayed messages */
        LASSERT(!do_recv || msg->msg_rx_delayed);
 
        if (!msg->msg_peerrtrcredit) {
-               LASSERT((lp->lp_rtrcredits < 0) ==
-                       !list_empty(&lp->lp_rtrq));
+               spin_lock(&lp->lpni_lock);
+               LASSERT((lp->lpni_rtrcredits < 0) ==
+                       !list_empty(&lp->lpni_rtrq));
 
                msg->msg_peerrtrcredit = 1;
-               lp->lp_rtrcredits--;
-               if (lp->lp_rtrcredits < lp->lp_minrtrcredits)
-                       lp->lp_minrtrcredits = lp->lp_rtrcredits;
+               lp->lpni_rtrcredits--;
+               if (lp->lpni_rtrcredits < lp->lpni_minrtrcredits)
+                       lp->lpni_minrtrcredits = lp->lpni_rtrcredits;
 
-               if (lp->lp_rtrcredits < 0) {
+               if (lp->lpni_rtrcredits < 0) {
                        /* must have checked eager_recv before here */
                        LASSERT(msg->msg_rx_ready_delay);
                        msg->msg_rx_delayed = 1;
-                       list_add_tail(&msg->msg_list, &lp->lp_rtrq);
+                       list_add_tail(&msg->msg_list, &lp->lpni_rtrq);
+                       spin_unlock(&lp->lpni_lock);
                        return LNET_CREDIT_WAIT;
                }
+               spin_unlock(&lp->lpni_lock);
        }
 
        rbp = lnet_msg2bufpool(msg);
@@ -944,7 +1078,7 @@ lnet_post_routed_recv_locked (lnet_msg_t *msg, int do_recv)
        }
 
        LASSERT(!list_empty(&rbp->rbp_bufs));
-       rb = list_entry(rbp->rbp_bufs.next, lnet_rtrbuf_t, rb_list);
+       rb = list_entry(rbp->rbp_bufs.next, struct lnet_rtrbuf, rb_list);
        list_del(&rb->rb_list);
 
        msg->msg_niov = rbp->rbp_npages;
@@ -954,7 +1088,7 @@ lnet_post_routed_recv_locked (lnet_msg_t *msg, int do_recv)
                int cpt = msg->msg_rx_cpt;
 
                lnet_net_unlock(cpt);
-               lnet_ni_recv(lp->lp_ni, msg->msg_private, msg, 1,
+               lnet_ni_recv(msg->msg_rxni, msg->msg_private, msg, 1,
                             0, msg->msg_len, msg->msg_len);
                lnet_net_lock(cpt);
        }
@@ -962,13 +1096,14 @@ lnet_post_routed_recv_locked (lnet_msg_t *msg, int do_recv)
 }
 
 void
-lnet_return_tx_credits_locked(lnet_msg_t *msg)
+lnet_return_tx_credits_locked(struct lnet_msg *msg)
 {
-       lnet_peer_t     *txpeer = msg->msg_txpeer;
-       lnet_msg_t      *msg2;
+       struct lnet_peer_ni     *txpeer = msg->msg_txpeer;
+       struct lnet_ni          *txni = msg->msg_txni;
+       struct lnet_msg         *msg2;
 
        if (msg->msg_txcredit) {
-               struct lnet_ni       *ni = txpeer->lp_ni;
+               struct lnet_ni       *ni = msg->msg_txni;
                struct lnet_tx_queue *tq = ni->ni_tx_queues[msg->msg_tx_cpt];
 
                /* give back NI txcredits */
@@ -978,13 +1113,15 @@ lnet_return_tx_credits_locked(lnet_msg_t *msg)
                        !list_empty(&tq->tq_delayed));
 
                tq->tq_credits++;
+               atomic_inc(&ni->ni_tx_credits);
                if (tq->tq_credits <= 0) {
                        msg2 = list_entry(tq->tq_delayed.next,
-                                         lnet_msg_t, msg_list);
+                                         struct lnet_msg, msg_list);
                        list_del(&msg2->msg_list);
 
-                       LASSERT(msg2->msg_txpeer->lp_ni == ni);
+                       LASSERT(msg2->msg_txni == ni);
                        LASSERT(msg2->msg_tx_delayed);
+                       LASSERT(msg2->msg_tx_cpt == msg->msg_tx_cpt);
 
                        (void) lnet_post_send_locked(msg2, 1);
                }
@@ -994,40 +1131,81 @@ lnet_return_tx_credits_locked(lnet_msg_t *msg)
                /* give back peer txcredits */
                msg->msg_peertxcredit = 0;
 
-               LASSERT((txpeer->lp_txcredits < 0) ==
-                       !list_empty(&txpeer->lp_txq));
+               spin_lock(&txpeer->lpni_lock);
+               LASSERT((txpeer->lpni_txcredits < 0) ==
+                       !list_empty(&txpeer->lpni_txq));
 
-               txpeer->lp_txqnob -= msg->msg_len + sizeof(lnet_hdr_t);
-               LASSERT(txpeer->lp_txqnob >= 0);
+               txpeer->lpni_txqnob -= msg->msg_len + sizeof(struct lnet_hdr);
+               LASSERT(txpeer->lpni_txqnob >= 0);
 
-               txpeer->lp_txcredits++;
-               if (txpeer->lp_txcredits <= 0) {
-                       msg2 = list_entry(txpeer->lp_txq.next,
-                                             lnet_msg_t, msg_list);
+               txpeer->lpni_txcredits++;
+               if (txpeer->lpni_txcredits <= 0) {
+                       int msg2_cpt;
+
+                       msg2 = list_entry(txpeer->lpni_txq.next,
+                                             struct lnet_msg, msg_list);
                        list_del(&msg2->msg_list);
+                       spin_unlock(&txpeer->lpni_lock);
 
                        LASSERT(msg2->msg_txpeer == txpeer);
                        LASSERT(msg2->msg_tx_delayed);
 
-                       (void) lnet_post_send_locked(msg2, 1);
+                       msg2_cpt = msg2->msg_tx_cpt;
+
+                       /*
+                        * The msg_cpt can be different from the msg2_cpt
+                        * so we need to make sure we lock the correct cpt
+                        * for msg2.
+                        * Once we call lnet_post_send_locked() it is no
+                        * longer safe to access msg2, since it could've
+                        * been freed by lnet_finalize(), but we still
+                        * need to relock the correct cpt, so we cache the
+                        * msg2_cpt for the purpose of the check that
+                        * follows the call to lnet_pose_send_locked().
+                        */
+                       if (msg2_cpt != msg->msg_tx_cpt) {
+                               lnet_net_unlock(msg->msg_tx_cpt);
+                               lnet_net_lock(msg2_cpt);
+                       }
+                        (void) lnet_post_send_locked(msg2, 1);
+                       if (msg2_cpt != msg->msg_tx_cpt) {
+                               lnet_net_unlock(msg2_cpt);
+                               lnet_net_lock(msg->msg_tx_cpt);
+                       }
+                } else {
+                       spin_unlock(&txpeer->lpni_lock);
                }
+        }
+
+       if (txni != NULL) {
+               msg->msg_txni = NULL;
+               lnet_ni_decref_locked(txni, msg->msg_tx_cpt);
        }
 
        if (txpeer != NULL) {
+               /*
+                * TODO:
+                * Once the patch for the health comes in we need to set
+                * the health of the peer ni to bad when we fail to send
+                * a message.
+                * int status = msg->msg_ev.status;
+                * if (status != 0)
+                *      lnet_set_peer_ni_health_locked(txpeer, false)
+                */
                msg->msg_txpeer = NULL;
-               lnet_peer_decref_locked(txpeer);
+               lnet_peer_ni_decref_locked(txpeer);
        }
 }
 
 void
-lnet_schedule_blocked_locked(lnet_rtrbufpool_t *rbp)
+lnet_schedule_blocked_locked(struct lnet_rtrbufpool *rbp)
 {
-       lnet_msg_t      *msg;
+       struct lnet_msg *msg;
 
        if (list_empty(&rbp->rbp_msgs))
                return;
        msg = list_entry(rbp->rbp_msgs.next,
-                        lnet_msg_t, msg_list);
+                        struct lnet_msg, msg_list);
        list_del(&msg->msg_list);
 
        (void)lnet_post_routed_recv_locked(msg, 1);
@@ -1036,43 +1214,39 @@ lnet_schedule_blocked_locked(lnet_rtrbufpool_t *rbp)
 void
 lnet_drop_routed_msgs_locked(struct list_head *list, int cpt)
 {
-       lnet_msg_t       *msg;
-       lnet_msg_t       *tmp;
-       struct list_head drop;
-
-       INIT_LIST_HEAD(&drop);
-
-       list_splice_init(list, &drop);
+       struct lnet_msg *msg;
+       struct lnet_msg *tmp;
 
        lnet_net_unlock(cpt);
 
-       list_for_each_entry_safe(msg, tmp, &drop, msg_list) {
-               lnet_ni_recv(msg->msg_rxpeer->lp_ni, msg->msg_private, NULL,
+       list_for_each_entry_safe(msg, tmp, list, msg_list) {
+               lnet_ni_recv(msg->msg_rxni, msg->msg_private, NULL,
                             0, 0, 0, msg->msg_hdr.payload_length);
                list_del_init(&msg->msg_list);
-               lnet_finalize(NULL, msg, -ECANCELED);
+               lnet_finalize(msg, -ECANCELED);
        }
 
        lnet_net_lock(cpt);
 }
 
 void
-lnet_return_rx_credits_locked(lnet_msg_t *msg)
+lnet_return_rx_credits_locked(struct lnet_msg *msg)
 {
-       lnet_peer_t     *rxpeer = msg->msg_rxpeer;
-       lnet_msg_t      *msg2;
+       struct lnet_peer_ni *rxpeer = msg->msg_rxpeer;
+       struct lnet_ni *rxni = msg->msg_rxni;
+       struct lnet_msg *msg2;
 
        if (msg->msg_rtrcredit) {
                /* give back global router credits */
-               lnet_rtrbuf_t     *rb;
-               lnet_rtrbufpool_t *rbp;
+               struct lnet_rtrbuf *rb;
+               struct lnet_rtrbufpool *rbp;
 
                /* NB If a msg ever blocks for a buffer in rbp_msgs, it stays
                 * there until it gets one allocated, or aborts the wait
                 * itself */
                LASSERT(msg->msg_kiov != NULL);
 
-               rb = list_entry(msg->msg_kiov, lnet_rtrbuf_t, rb_kiov[0]);
+               rb = list_entry(msg->msg_kiov, struct lnet_rtrbuf, rb_kiov[0]);
                rbp = rb->rb_pool;
 
                msg->msg_kiov = NULL;
@@ -1111,87 +1285,109 @@ routing_off:
                /* give back peer router credits */
                msg->msg_peerrtrcredit = 0;
 
-               LASSERT((rxpeer->lp_rtrcredits < 0) ==
-                       !list_empty(&rxpeer->lp_rtrq));
+               spin_lock(&rxpeer->lpni_lock);
+               LASSERT((rxpeer->lpni_rtrcredits < 0) ==
+                       !list_empty(&rxpeer->lpni_rtrq));
 
-               rxpeer->lp_rtrcredits++;
+               rxpeer->lpni_rtrcredits++;
 
                /* drop all messages which are queued to be routed on that
                 * peer. */
                if (!the_lnet.ln_routing) {
-                       lnet_drop_routed_msgs_locked(&rxpeer->lp_rtrq,
-                                                    msg->msg_rx_cpt);
-               } else if (rxpeer->lp_rtrcredits <= 0) {
-                       msg2 = list_entry(rxpeer->lp_rtrq.next,
-                                         lnet_msg_t, msg_list);
+                       struct list_head drop;
+                       INIT_LIST_HEAD(&drop);
+                       list_splice_init(&rxpeer->lpni_rtrq, &drop);
+                       spin_unlock(&rxpeer->lpni_lock);
+                       lnet_drop_routed_msgs_locked(&drop, msg->msg_rx_cpt);
+               } else if (rxpeer->lpni_rtrcredits <= 0) {
+                       msg2 = list_entry(rxpeer->lpni_rtrq.next,
+                                         struct lnet_msg, msg_list);
                        list_del(&msg2->msg_list);
-
+                       spin_unlock(&rxpeer->lpni_lock);
                        (void) lnet_post_routed_recv_locked(msg2, 1);
+               } else {
+                       spin_unlock(&rxpeer->lpni_lock);
                }
        }
+       if (rxni != NULL) {
+               msg->msg_rxni = NULL;
+               lnet_ni_decref_locked(rxni, msg->msg_rx_cpt);
+       }
        if (rxpeer != NULL) {
                msg->msg_rxpeer = NULL;
-               lnet_peer_decref_locked(rxpeer);
+               lnet_peer_ni_decref_locked(rxpeer);
        }
 }
 
 static int
-lnet_compare_routes(lnet_route_t *r1, lnet_route_t *r2)
+lnet_compare_peers(struct lnet_peer_ni *p1, struct lnet_peer_ni *p2)
 {
-       lnet_peer_t *p1 = r1->lr_gateway;
-       lnet_peer_t *p2 = r2->lr_gateway;
+       if (p1->lpni_txqnob < p2->lpni_txqnob)
+               return 1;
+
+       if (p1->lpni_txqnob > p2->lpni_txqnob)
+               return -1;
+
+       if (p1->lpni_txcredits > p2->lpni_txcredits)
+               return 1;
+
+       if (p1->lpni_txcredits < p2->lpni_txcredits)
+               return -1;
+
+       return 0;
+}
+
+static int
+lnet_compare_routes(struct lnet_route *r1, struct lnet_route *r2)
+{
+       struct lnet_peer_ni *p1 = r1->lr_gateway;
+       struct lnet_peer_ni *p2 = r2->lr_gateway;
        int r1_hops = (r1->lr_hops == LNET_UNDEFINED_HOPS) ? 1 : r1->lr_hops;
        int r2_hops = (r2->lr_hops == LNET_UNDEFINED_HOPS) ? 1 : r2->lr_hops;
+       int rc;
 
        if (r1->lr_priority < r2->lr_priority)
                return 1;
 
        if (r1->lr_priority > r2->lr_priority)
-               return -ERANGE;
+               return -1;
 
        if (r1_hops < r2_hops)
                return 1;
 
        if (r1_hops > r2_hops)
-               return -ERANGE;
-
-       if (p1->lp_txqnob < p2->lp_txqnob)
-               return 1;
-
-       if (p1->lp_txqnob > p2->lp_txqnob)
-               return -ERANGE;
+               return -1;
 
-       if (p1->lp_txcredits > p2->lp_txcredits)
-               return 1;
-
-       if (p1->lp_txcredits < p2->lp_txcredits)
-               return -ERANGE;
+       rc = lnet_compare_peers(p1, p2);
+       if (rc)
+               return rc;
 
        if (r1->lr_seq - r2->lr_seq <= 0)
                return 1;
 
-       return -ERANGE;
+       return -1;
 }
 
-static lnet_peer_t *
-lnet_find_route_locked(lnet_ni_t *ni, lnet_nid_t target, lnet_nid_t rtr_nid)
+static struct lnet_peer_ni *
+lnet_find_route_locked(struct lnet_net *net, lnet_nid_t target,
+                      lnet_nid_t rtr_nid)
 {
-       lnet_remotenet_t        *rnet;
-       lnet_route_t            *route;
-       lnet_route_t            *best_route;
-       lnet_route_t            *last_route;
-       struct lnet_peer        *lp_best;
-       struct lnet_peer        *lp;
+       struct lnet_remotenet   *rnet;
+       struct lnet_route               *route;
+       struct lnet_route               *best_route;
+       struct lnet_route               *last_route;
+       struct lnet_peer_ni     *lpni_best;
+       struct lnet_peer_ni     *lp;
        int                     rc;
 
        /* If @rtr_nid is not LNET_NID_ANY, return the gateway with
         * rtr_nid nid, otherwise find the best gateway I can use */
 
-       rnet = lnet_find_net_locked(LNET_NIDNET(target));
+       rnet = lnet_find_rnet_locked(LNET_NIDNET(target));
        if (rnet == NULL)
                return NULL;
 
-       lp_best = NULL;
+       lpni_best = NULL;
        best_route = last_route = NULL;
        list_for_each_entry(route, &rnet->lrn_routes, lr_list) {
                lp = route->lr_gateway;
@@ -1199,15 +1395,15 @@ lnet_find_route_locked(lnet_ni_t *ni, lnet_nid_t target, lnet_nid_t rtr_nid)
                if (!lnet_is_route_alive(route))
                        continue;
 
-               if (ni != NULL && lp->lp_ni != ni)
+               if (net != NULL && lp->lpni_net != net)
                        continue;
 
-               if (lp->lp_nid == rtr_nid) /* it's pre-determined router */
+               if (lp->lpni_nid == rtr_nid) /* it's pre-determined router */
                        return lp;
 
-               if (lp_best == NULL) {
+               if (lpni_best == NULL) {
                        best_route = last_route = route;
-                       lp_best = lp;
+                       lpni_best = lp;
                        continue;
                }
 
@@ -1220,7 +1416,7 @@ lnet_find_route_locked(lnet_ni_t *ni, lnet_nid_t target, lnet_nid_t rtr_nid)
                        continue;
 
                best_route = route;
-               lp_best = lp;
+               lpni_best = lp;
        }
 
        /* set sequence number on the best router to the latest sequence + 1
@@ -1228,185 +1424,726 @@ lnet_find_route_locked(lnet_ni_t *ni, lnet_nid_t target, lnet_nid_t rtr_nid)
         * harmless and functional  */
        if (best_route != NULL)
                best_route->lr_seq = last_route->lr_seq + 1;
-       return lp_best;
+       return lpni_best;
 }
 
-int
-lnet_send(lnet_nid_t src_nid, lnet_msg_t *msg, lnet_nid_t rtr_nid)
+static struct lnet_ni *
+lnet_get_best_ni(struct lnet_net *local_net, struct lnet_ni *cur_ni,
+                int md_cpt)
 {
-       lnet_nid_t              dst_nid = msg->msg_target.nid;
-       struct lnet_ni          *src_ni;
-       struct lnet_ni          *local_ni;
-       struct lnet_peer        *lp;
-       int                     cpt;
-       int                     cpt2;
-       int                     rc;
+       struct lnet_ni *ni = NULL, *best_ni = cur_ni;
+       unsigned int shortest_distance;
+       int best_credits;
 
-       /* NB: rtr_nid is set to LNET_NID_ANY for all current use-cases,
-        * but we might want to use pre-determined router for ACK/REPLY
-        * in the future */
-       /* NB: ni != NULL == interface pre-determined (ACK/REPLY) */
-       LASSERT(msg->msg_txpeer == NULL);
-       LASSERT(!msg->msg_sending);
-       LASSERT(!msg->msg_target_is_router);
-       LASSERT(!msg->msg_receiving);
+       if (best_ni == NULL) {
+               shortest_distance = UINT_MAX;
+               best_credits = INT_MIN;
+       } else {
+               shortest_distance = cfs_cpt_distance(lnet_cpt_table(), md_cpt,
+                                                    best_ni->ni_dev_cpt);
+               best_credits = atomic_read(&best_ni->ni_tx_credits);
+       }
 
-       msg->msg_sending = 1;
+       while ((ni = lnet_get_next_ni_locked(local_net, ni))) {
+               unsigned int distance;
+               int ni_credits;
 
-       LASSERT(!msg->msg_tx_committed);
-       cpt = lnet_cpt_of_nid(rtr_nid == LNET_NID_ANY ? dst_nid : rtr_nid);
- again:
-       lnet_net_lock(cpt);
+               if (!lnet_is_ni_healthy_locked(ni))
+                       continue;
+
+               ni_credits = atomic_read(&ni->ni_tx_credits);
+
+               /*
+                * calculate the distance from the CPT on which
+                * the message memory is allocated to the CPT of
+                * the NI's physical device
+                */
+               distance = cfs_cpt_distance(lnet_cpt_table(),
+                                           md_cpt,
+                                           ni->ni_dev_cpt);
+
+               /*
+                * All distances smaller than the NUMA range
+                * are treated equally.
+                */
+               if (distance < lnet_numa_range)
+                       distance = lnet_numa_range;
+
+               /*
+                * Select on shorter distance, then available
+                * credits, then round-robin.
+                */
+               if (distance > shortest_distance) {
+                       continue;
+               } else if (distance < shortest_distance) {
+                       shortest_distance = distance;
+               } else if (ni_credits < best_credits) {
+                       continue;
+               } else if (ni_credits == best_credits) {
+                       if (best_ni && (best_ni)->ni_seq <= ni->ni_seq)
+                               continue;
+               }
+               best_ni = ni;
+               best_credits = ni_credits;
+       }
 
-       if (the_lnet.ln_shutdown) {
+       return best_ni;
+}
+
+/*
+ * Traffic to the LNET_RESERVED_PORTAL may not trigger peer discovery,
+ * because such traffic is required to perform discovery. We therefore
+ * exclude all GET and PUT on that portal. We also exclude all ACK and
+ * REPLY traffic, but that is because the portal is not tracked in the
+ * message structure for these message types. We could restrict this
+ * further by also checking for LNET_PROTO_PING_MATCHBITS.
+ */
+static bool
+lnet_msg_discovery(struct lnet_msg *msg)
+{
+       if (msg->msg_type == LNET_MSG_PUT) {
+               if (msg->msg_hdr.msg.put.ptl_index != LNET_RESERVED_PORTAL)
+                       return true;
+       } else if (msg->msg_type == LNET_MSG_GET) {
+               if (msg->msg_hdr.msg.get.ptl_index != LNET_RESERVED_PORTAL)
+                       return true;
+       }
+       return false;
+}
+
+static int
+lnet_select_pathway(lnet_nid_t src_nid, lnet_nid_t dst_nid,
+                   struct lnet_msg *msg, lnet_nid_t rtr_nid)
+{
+       struct lnet_ni          *best_ni;
+       struct lnet_peer_ni     *best_lpni;
+       struct lnet_peer_ni     *best_gw;
+       struct lnet_peer_ni     *lpni;
+       struct lnet_peer_ni     *final_dst;
+       struct lnet_peer        *peer;
+       struct lnet_peer_net    *peer_net;
+       struct lnet_net         *local_net;
+       int                     cpt, cpt2, rc;
+       bool                    routing;
+       bool                    routing2;
+       bool                    ni_is_pref;
+       bool                    preferred;
+       bool                    local_found;
+       int                     best_lpni_credits;
+       int                     md_cpt;
+
+       /*
+        * get an initial CPT to use for locking. The idea here is not to
+        * serialize the calls to select_pathway, so that as many
+        * operations can run concurrently as possible. To do that we use
+        * the CPT where this call is being executed. Later on when we
+        * determine the CPT to use in lnet_message_commit, we switch the
+        * lock and check if there was any configuration change.  If none,
+        * then we proceed, if there is, then we restart the operation.
+        */
+       cpt = lnet_net_lock_current();
+
+       md_cpt = lnet_cpt_of_md(msg->msg_md, msg->msg_offset);
+       if (md_cpt == CFS_CPT_ANY)
+               md_cpt = cpt;
+
+again:
+       best_ni = NULL;
+       best_lpni = NULL;
+       best_gw = NULL;
+       final_dst = NULL;
+       local_net = NULL;
+       routing = false;
+       routing2 = false;
+       local_found = false;
+
+       /*
+        * lnet_nid2peerni_locked() is the path that will find an
+        * existing peer_ni, or create one and mark it as having been
+        * created due to network traffic.
+        */
+       lpni = lnet_nid2peerni_locked(dst_nid, LNET_NID_ANY, cpt);
+       if (IS_ERR(lpni)) {
                lnet_net_unlock(cpt);
-               return -ESHUTDOWN;
+               return PTR_ERR(lpni);
        }
+       /*
+        * Now that we have a peer_ni, check if we want to discover
+        * the peer. Traffic to the LNET_RESERVED_PORTAL should not
+        * trigger discovery.
+        */
+       peer = lpni->lpni_peer_net->lpn_peer;
+       if (lnet_msg_discovery(msg) && !lnet_peer_is_uptodate(peer)) {
+               rc = lnet_discover_peer_locked(lpni, cpt, false);
+               if (rc) {
+                       lnet_peer_ni_decref_locked(lpni);
+                       lnet_net_unlock(cpt);
+                       return rc;
+               }
+               /* The peer may have changed. */
+               peer = lpni->lpni_peer_net->lpn_peer;
+               /* queue message and return */
+               msg->msg_src_nid_param = src_nid;
+               msg->msg_rtr_nid_param = rtr_nid;
+               msg->msg_sending = 0;
+               list_add_tail(&msg->msg_list, &peer->lp_dc_pendq);
+               lnet_peer_ni_decref_locked(lpni);
+               lnet_net_unlock(cpt);
 
-       if (src_nid == LNET_NID_ANY) {
-               src_ni = NULL;
-       } else {
-               src_ni = lnet_nid2ni_locked(src_nid, cpt);
-               if (src_ni == NULL) {
+               CDEBUG(D_NET, "%s pending discovery\n",
+                      libcfs_nid2str(peer->lp_primary_nid));
+
+               return LNET_DC_WAIT;
+       }
+       lnet_peer_ni_decref_locked(lpni);
+
+       /* If peer is not healthy then can not send anything to it */
+       if (!lnet_is_peer_healthy_locked(peer)) {
+               lnet_net_unlock(cpt);
+               return -EHOSTUNREACH;
+       }
+
+       /*
+        * STEP 1: first jab at determining best_ni
+        * if src_nid is explicitly specified, then best_ni is already
+        * pre-determiend for us. Otherwise we need to select the best
+        * one to use later on
+        */
+       if (src_nid != LNET_NID_ANY) {
+               best_ni = lnet_nid2ni_locked(src_nid, cpt);
+               if (!best_ni) {
                        lnet_net_unlock(cpt);
                        LCONSOLE_WARN("Can't send to %s: src %s is not a "
                                      "local nid\n", libcfs_nid2str(dst_nid),
                                      libcfs_nid2str(src_nid));
                        return -EINVAL;
                }
-               LASSERT(!msg->msg_routing);
        }
 
-       /* Is this for someone on a local network? */
-       local_ni = lnet_net2ni_locked(LNET_NIDNET(dst_nid), cpt);
+       if (msg->msg_type == LNET_MSG_REPLY ||
+           msg->msg_type == LNET_MSG_ACK ||
+           !lnet_peer_is_multi_rail(peer) ||
+           best_ni) {
+               /*
+                * for replies we want to respond on the same peer_ni we
+                * received the message on if possible. If not, then pick
+                * a peer_ni to send to
+                *
+                * if the peer is non-multi-rail then you want to send to
+                * the dst_nid provided as well.
+                *
+                * If the best_ni has already been determined, IE the
+                * src_nid has been specified, then use the
+                * destination_nid provided as well, since we're
+                * continuing a series of related messages for the same
+                * RPC.
+                *
+                * It is expected to find the lpni using dst_nid, since we
+                * created it earlier.
+                */
+               best_lpni = lnet_find_peer_ni_locked(dst_nid);
+               if (best_lpni)
+                       lnet_peer_ni_decref_locked(best_lpni);
+
+               if (best_lpni && !lnet_get_net_locked(LNET_NIDNET(dst_nid))) {
+                       /*
+                        * this lpni is not on a local network so we need
+                        * to route this reply.
+                        */
+                       best_gw = lnet_find_route_locked(NULL,
+                                                        best_lpni->lpni_nid,
+                                                        rtr_nid);
+                       if (best_gw) {
+                               /*
+                               * RULE: Each node considers only the next-hop
+                               *
+                               * We're going to route the message, so change the peer to
+                               * the router.
+                               */
+                               LASSERT(best_gw->lpni_peer_net);
+                               LASSERT(best_gw->lpni_peer_net->lpn_peer);
+                               peer = best_gw->lpni_peer_net->lpn_peer;
+
+                               /*
+                               * if the router is not multi-rail then use the best_gw
+                               * found to send the message to
+                               */
+                               if (!lnet_peer_is_multi_rail(peer))
+                                       best_lpni = best_gw;
+                               else
+                                       best_lpni = NULL;
 
-       if (local_ni != NULL) {
-               if (src_ni == NULL) {
-                       src_ni = local_ni;
-                       src_nid = src_ni->ni_nid;
-               } else if (src_ni == local_ni) {
-                       lnet_ni_decref_locked(local_ni, cpt);
-               } else {
-                       lnet_ni_decref_locked(local_ni, cpt);
-                       lnet_ni_decref_locked(src_ni, cpt);
+                               routing = true;
+                       } else {
+                               best_lpni = NULL;
+                       }
+               } else if (!best_lpni) {
                        lnet_net_unlock(cpt);
-                       LCONSOLE_WARN("No route to %s via from %s\n",
-                                     libcfs_nid2str(dst_nid),
-                                     libcfs_nid2str(src_nid));
+                       CERROR("unable to send msg_type %d to "
+                             "originating %s. Destination NID not in DB\n",
+                             msg->msg_type, libcfs_nid2str(dst_nid));
                        return -EINVAL;
                }
+       }
 
-               LASSERT(src_nid != LNET_NID_ANY);
-               lnet_msg_commit(msg, cpt);
-
-               if (!msg->msg_routing)
-                       msg->msg_hdr.src_nid = cpu_to_le64(src_nid);
-
-               if (src_ni == the_lnet.ln_loni) {
-                       /* No send credit hassles with LOLND */
+       /*
+        * We must use a consistent source address when sending to a
+        * non-MR peer. However, a non-MR peer can have multiple NIDs
+        * on multiple networks, and we may even need to talk to this
+        * peer on multiple networks -- certain types of
+        * load-balancing configuration do this.
+        *
+        * So we need to pick the NI the peer prefers for this
+        * particular network.
+        */
+       if (!lnet_peer_is_multi_rail(peer)) {
+               if (!best_lpni) {
                        lnet_net_unlock(cpt);
-                       lnet_ni_send(src_ni, msg);
+                       CERROR("no route to %s\n",
+                              libcfs_nid2str(dst_nid));
+                       return -EHOSTUNREACH;
+               }
 
-                       lnet_net_lock(cpt);
-                       lnet_ni_decref_locked(src_ni, cpt);
-                       lnet_net_unlock(cpt);
-                       return 0;
+               /* best ni is already set if src_nid was provided */
+               if (!best_ni) {
+                       /* Get the target peer_ni */
+                       peer_net = lnet_peer_get_net_locked(peer,
+                                       LNET_NIDNET(best_lpni->lpni_nid));
+                       LASSERT(peer_net != NULL);
+                       list_for_each_entry(lpni, &peer_net->lpn_peer_nis,
+                                           lpni_peer_nis) {
+                               if (lpni->lpni_pref_nnids == 0)
+                                       continue;
+                               LASSERT(lpni->lpni_pref_nnids == 1);
+                               best_ni = lnet_nid2ni_locked(
+                                               lpni->lpni_pref.nid, cpt);
+                               break;
+                       }
                }
+               /* if best_ni is still not set just pick one */
+               if (!best_ni) {
+                       best_ni = lnet_net2ni_locked(
+                               best_lpni->lpni_net->net_id, cpt);
+                       /* If there is no best_ni we don't have a route */
+                       if (!best_ni) {
+                               lnet_net_unlock(cpt);
+                               CERROR("no path to %s from net %s\n",
+                                       libcfs_nid2str(best_lpni->lpni_nid),
+                                       libcfs_net2str(best_lpni->lpni_net->net_id));
+                               return -EHOSTUNREACH;
+                       }
+                       lpni = list_entry(peer_net->lpn_peer_nis.next,
+                                       struct lnet_peer_ni,
+                                       lpni_peer_nis);
+               }
+               /* Set preferred NI if necessary. */
+               if (lpni->lpni_pref_nnids == 0)
+                       lnet_peer_ni_set_non_mr_pref_nid(lpni, best_ni->ni_nid);
+       }
 
-               rc = lnet_nid2peer_locked(&lp, dst_nid, cpt);
-               /* lp has ref on src_ni; lose mine */
-               lnet_ni_decref_locked(src_ni, cpt);
-               if (rc != 0) {
-                       lnet_net_unlock(cpt);
-                       LCONSOLE_WARN("Error %d finding peer %s\n", rc,
-                                     libcfs_nid2str(dst_nid));
-                       /* ENOMEM or shutting down */
-                       return rc;
+       /*
+        * if we already found a best_ni because src_nid is specified and
+        * best_lpni because we are replying to a message then just send
+        * the message
+        */
+       if (best_ni && best_lpni)
+               goto send;
+
+       /*
+        * If we already found a best_ni because src_nid is specified then
+        * pick the peer then send the message
+        */
+       if (best_ni)
+               goto pick_peer;
+
+       /*
+        * pick the best_ni by going through all the possible networks of
+        * that peer and see which local NI is best suited to talk to that
+        * peer.
+        *
+        * Locally connected networks will always be preferred over
+        * a routed network. If there are only routed paths to the peer,
+        * then the best route is chosen. If all routes are equal then
+        * they are used in round robin.
+        */
+       list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) {
+               if (!lnet_is_peer_net_healthy_locked(peer_net))
+                       continue;
+
+               local_net = lnet_get_net_locked(peer_net->lpn_net_id);
+               if (!local_net && !routing && !local_found) {
+                       struct lnet_peer_ni *net_gw;
+
+                       lpni = list_entry(peer_net->lpn_peer_nis.next,
+                                         struct lnet_peer_ni,
+                                         lpni_peer_nis);
+
+                       net_gw = lnet_find_route_locked(NULL,
+                                                       lpni->lpni_nid,
+                                                       rtr_nid);
+                       if (!net_gw)
+                               continue;
+
+                       if (best_gw) {
+                               /*
+                                * lnet_find_route_locked() call
+                                * will return the best_Gw on the
+                                * lpni->lpni_nid network.
+                                * However, best_gw and net_gw can
+                                * be on different networks.
+                                * Therefore need to compare them
+                                * to pick the better of either.
+                                */
+                               if (lnet_compare_peers(best_gw, net_gw) > 0)
+                                       continue;
+                               if (best_gw->lpni_gw_seq <= net_gw->lpni_gw_seq)
+                                       continue;
+                       }
+                       best_gw = net_gw;
+                       final_dst = lpni;
+
+                       routing2 = true;
+               } else {
+                       best_gw = NULL;
+                       final_dst = NULL;
+                       routing2 = false;
+                       local_found = true;
                }
-               LASSERT(lp->lp_ni == src_ni);
-       } else {
-               /* sending to a remote network */
-               lp = lnet_find_route_locked(src_ni, dst_nid, rtr_nid);
-               if (lp == NULL) {
-                       if (src_ni != NULL)
-                               lnet_ni_decref_locked(src_ni, cpt);
-                       lnet_net_unlock(cpt);
 
-                       LCONSOLE_WARN("No route to %s via %s "
-                                     "(all routers down)\n",
-                                     libcfs_id2str(msg->msg_target),
-                                     libcfs_nid2str(src_nid));
+               /*
+                * a gw on this network is found, but there could be
+                * other better gateways on other networks. So don't pick
+                * the best_ni until we determine the best_gw.
+                */
+               if (best_gw)
+                       continue;
+
+               /* if no local_net found continue */
+               if (!local_net)
+                       continue;
+
+               /*
+                * Iterate through the NIs in this local Net and select
+                * the NI to send from. The selection is determined by
+                * these 3 criterion in the following priority:
+                *      1. NUMA
+                *      2. NI available credits
+                *      3. Round Robin
+                */
+               best_ni = lnet_get_best_ni(local_net, best_ni, md_cpt);
+       }
+
+       if (!best_ni && !best_gw) {
+               lnet_net_unlock(cpt);
+               LCONSOLE_WARN("No local ni found to send from to %s\n",
+                       libcfs_nid2str(dst_nid));
+               return -EINVAL;
+       }
+
+       if (!best_ni) {
+               best_ni = lnet_get_best_ni(best_gw->lpni_net, best_ni, md_cpt);
+               LASSERT(best_gw && best_ni);
+
+               /*
+                * We're going to route the message, so change the peer to
+                * the router.
+                */
+               LASSERT(best_gw->lpni_peer_net);
+               LASSERT(best_gw->lpni_peer_net->lpn_peer);
+               best_gw->lpni_gw_seq++;
+               peer = best_gw->lpni_peer_net->lpn_peer;
+       }
+
+       /*
+        * Now that we selected the NI to use increment its sequence
+        * number so the Round Robin algorithm will detect that it has
+        * been used and pick the next NI.
+        */
+       best_ni->ni_seq++;
+
+pick_peer:
+       /*
+        * At this point the best_ni is on a local network on which
+        * the peer has a peer_ni as well
+        */
+       peer_net = lnet_peer_get_net_locked(peer,
+                                           best_ni->ni_net->net_id);
+       /*
+        * peer_net is not available or the src_nid is explicitly defined
+        * and the peer_net for that src_nid is unhealthy. find a route to
+        * the destination nid.
+        */
+       if (!peer_net ||
+           (src_nid != LNET_NID_ANY &&
+            !lnet_is_peer_net_healthy_locked(peer_net))) {
+               best_gw = lnet_find_route_locked(best_ni->ni_net,
+                                                dst_nid,
+                                                rtr_nid);
+               /*
+                * if no route is found for that network then
+                * move onto the next peer_ni in the peer
+                */
+               if (!best_gw) {
+                       lnet_net_unlock(cpt);
+                       LCONSOLE_WARN("No route to peer from %s\n",
+                               libcfs_nid2str(best_ni->ni_nid));
                        return -EHOSTUNREACH;
                }
 
-               /* rtr_nid is LNET_NID_ANY or NID of pre-determined router,
-                * it's possible that rtr_nid isn't LNET_NID_ANY and lp isn't
-                * pre-determined router, this can happen if router table
-                * was changed when we release the lock */
-               if (rtr_nid != lp->lp_nid) {
-                       cpt2 = lnet_cpt_of_nid_locked(lp->lp_nid);
-                       if (cpt2 != cpt) {
-                               if (src_ni != NULL)
-                                       lnet_ni_decref_locked(src_ni, cpt);
-                               lnet_net_unlock(cpt);
+               CDEBUG(D_NET, "Best route to %s via %s for %s %d\n",
+                       libcfs_nid2str(dst_nid),
+                       libcfs_nid2str(best_gw->lpni_nid),
+                       lnet_msgtyp2str(msg->msg_type), msg->msg_len);
 
-                               rtr_nid = lp->lp_nid;
-                               cpt = cpt2;
-                               goto again;
+               routing2 = true;
+               /*
+                * RULE: Each node considers only the next-hop
+                *
+                * We're going to route the message, so change the peer to
+                * the router.
+                */
+               LASSERT(best_gw->lpni_peer_net);
+               LASSERT(best_gw->lpni_peer_net->lpn_peer);
+               peer = best_gw->lpni_peer_net->lpn_peer;
+       } else if (!lnet_is_peer_net_healthy_locked(peer_net)) {
+               /*
+                * this peer_net is unhealthy but we still have an opportunity
+                * to find another peer_net that we can use
+                */
+               __u32 net_id = peer_net->lpn_net_id;
+               LCONSOLE_WARN("peer net %s unhealthy\n",
+                             libcfs_net2str(net_id));
+               goto again;
+       }
+
+       /*
+        * Look at the peer NIs for the destination peer that connect
+        * to the chosen net. If a peer_ni is preferred when using the
+        * best_ni to communicate, we use that one. If there is no
+        * preferred peer_ni, or there are multiple preferred peer_ni,
+        * the available transmit credits are used. If the transmit
+        * credits are equal, we round-robin over the peer_ni.
+        */
+       lpni = NULL;
+       best_lpni_credits = INT_MIN;
+       preferred = false;
+       best_lpni = NULL;
+       while ((lpni = lnet_get_next_peer_ni_locked(peer, peer_net, lpni))) {
+               /*
+                * if this peer ni is not healthy just skip it, no point in
+                * examining it further
+                */
+               if (!lnet_is_peer_ni_healthy_locked(lpni))
+                       continue;
+               ni_is_pref = lnet_peer_is_pref_nid_locked(lpni,
+                                                         best_ni->ni_nid);
+
+               /* if this is a preferred peer use it */
+               if (!preferred && ni_is_pref) {
+                       preferred = true;
+               } else if (preferred && !ni_is_pref) {
+                       /*
+                        * this is not the preferred peer so let's ignore
+                        * it.
+                        */
+                       continue;
+               } else if (lpni->lpni_txcredits < best_lpni_credits) {
+                       /*
+                        * We already have a peer that has more credits
+                        * available than this one. No need to consider
+                        * this peer further.
+                        */
+                       continue;
+               } else if (lpni->lpni_txcredits == best_lpni_credits) {
+                       /*
+                        * The best peer found so far and the current peer
+                        * have the same number of available credits let's
+                        * make sure to select between them using Round
+                        * Robin
+                        */
+                       if (best_lpni) {
+                               if (best_lpni->lpni_seq <= lpni->lpni_seq)
+                                       continue;
                        }
                }
 
-               CDEBUG(D_NET, "Best route to %s via %s for %s %d\n",
-                      libcfs_nid2str(dst_nid), libcfs_nid2str(lp->lp_nid),
-                      lnet_msgtyp2str(msg->msg_type), msg->msg_len);
+               best_lpni = lpni;
+               best_lpni_credits = lpni->lpni_txcredits;
+       }
 
-               if (src_ni == NULL) {
-                       src_ni = lp->lp_ni;
-                       src_nid = src_ni->ni_nid;
-               } else {
-                       LASSERT(src_ni == lp->lp_ni);
-                       lnet_ni_decref_locked(src_ni, cpt);
-               }
+       /* if we still can't find a peer ni then we can't reach it */
+       if (!best_lpni) {
+               __u32 net_id = (peer_net) ? peer_net->lpn_net_id :
+                       LNET_NIDNET(dst_nid);
+               lnet_net_unlock(cpt);
+               LCONSOLE_WARN("no peer_ni found on peer net %s\n",
+                               libcfs_net2str(net_id));
+               return -EHOSTUNREACH;
+       }
 
-               lnet_peer_addref_locked(lp);
 
-               LASSERT(src_nid != LNET_NID_ANY);
+send:
+       /* Shortcut for loopback. */
+       if (best_ni == the_lnet.ln_loni) {
+               /* No send credit hassles with LOLND */
+               lnet_ni_addref_locked(best_ni, cpt);
+               msg->msg_hdr.dest_nid = cpu_to_le64(best_ni->ni_nid);
+               if (!msg->msg_routing)
+                       msg->msg_hdr.src_nid = cpu_to_le64(best_ni->ni_nid);
+               msg->msg_target.nid = best_ni->ni_nid;
                lnet_msg_commit(msg, cpt);
+               msg->msg_txni = best_ni;
+               lnet_net_unlock(cpt);
 
-               if (!msg->msg_routing) {
-                       /* I'm the source and now I know which NI to send on */
-                       msg->msg_hdr.src_nid = cpu_to_le64(src_nid);
+               return LNET_CREDIT_OK;
+       }
+
+       routing = routing || routing2;
+
+       /*
+        * Increment sequence number of the peer selected so that we
+        * pick the next one in Round Robin.
+        */
+       best_lpni->lpni_seq++;
+
+       /*
+        * grab a reference on the peer_ni so it sticks around even if
+        * we need to drop and relock the lnet_net_lock below.
+        */
+       lnet_peer_ni_addref_locked(best_lpni);
+
+       /*
+        * Use lnet_cpt_of_nid() to determine the CPT used to commit the
+        * message. This ensures that we get a CPT that is correct for
+        * the NI when the NI has been restricted to a subset of all CPTs.
+        * If the selected CPT differs from the one currently locked, we
+        * must unlock and relock the lnet_net_lock(), and then check whether
+        * the configuration has changed. We don't have a hold on the best_ni
+        * yet, and it may have vanished.
+        */
+       cpt2 = lnet_cpt_of_nid_locked(best_lpni->lpni_nid, best_ni);
+       if (cpt != cpt2) {
+               __u32 seq = lnet_get_dlc_seq_locked();
+               lnet_net_unlock(cpt);
+               cpt = cpt2;
+               lnet_net_lock(cpt);
+               if (seq != lnet_get_dlc_seq_locked()) {
+                       lnet_peer_ni_decref_locked(best_lpni);
+                       goto again;
                }
+       }
+
+       /*
+        * store the best_lpni in the message right away to avoid having
+        * to do the same operation under different conditions
+        */
+       msg->msg_txpeer = best_lpni;
+       msg->msg_txni = best_ni;
+
+       /*
+        * grab a reference for the best_ni since now it's in use in this
+        * send. the reference will need to be dropped when the message is
+        * finished in lnet_finalize()
+        */
+       lnet_ni_addref_locked(msg->msg_txni, cpt);
+
+       /*
+        * Always set the target.nid to the best peer picked. Either the
+        * nid will be one of the preconfigured NIDs, or the same NID as
+        * what was originally set in the target or it will be the NID of
+        * a router if this message should be routed
+        */
+       msg->msg_target.nid = msg->msg_txpeer->lpni_nid;
+
+       /*
+        * lnet_msg_commit assigns the correct cpt to the message, which
+        * is used to decrement the correct refcount on the ni when it's
+        * time to return the credits
+        */
+       lnet_msg_commit(msg, cpt);
+
+       /*
+        * If we are routing the message then we don't need to overwrite
+        * the src_nid since it would've been set at the origin. Otherwise
+        * we are the originator so we need to set it.
+        */
+       if (!msg->msg_routing)
+               msg->msg_hdr.src_nid = cpu_to_le64(msg->msg_txni->ni_nid);
 
+       if (routing) {
                msg->msg_target_is_router = 1;
-               msg->msg_target.nid = lp->lp_nid;
                msg->msg_target.pid = LNET_PID_LUSTRE;
+               /*
+                * since we're routing we want to ensure that the
+                * msg_hdr.dest_nid is set to the final destination. When
+                * the router receives this message it knows how to route
+                * it.
+                */
+               msg->msg_hdr.dest_nid =
+                       cpu_to_le64(final_dst ? final_dst->lpni_nid : dst_nid);
+       } else {
+               /*
+                * if we're not routing set the dest_nid to the best peer
+                * ni that we picked earlier in the algorithm.
+                */
+               msg->msg_hdr.dest_nid = cpu_to_le64(msg->msg_txpeer->lpni_nid);
        }
 
-       /* 'lp' is our best choice of peer */
-
-       LASSERT(!msg->msg_peertxcredit);
-       LASSERT(!msg->msg_txcredit);
-       LASSERT(msg->msg_txpeer == NULL);
+       rc = lnet_post_send_locked(msg, 0);
 
-       msg->msg_txpeer = lp;                   /* msg takes my ref on lp */
+       if (!rc)
+               CDEBUG(D_NET, "TRACE: %s(%s:%s) -> %s(%s:%s) : %s\n",
+                      libcfs_nid2str(msg->msg_hdr.src_nid),
+                      libcfs_nid2str(msg->msg_txni->ni_nid),
+                      libcfs_nid2str(src_nid),
+                      libcfs_nid2str(msg->msg_hdr.dest_nid),
+                      libcfs_nid2str(dst_nid),
+                      libcfs_nid2str(msg->msg_txpeer->lpni_nid),
+                      lnet_msgtyp2str(msg->msg_type));
 
-       rc = lnet_post_send_locked(msg, 0);
        lnet_net_unlock(cpt);
 
+       return rc;
+}
+
+int
+lnet_send(lnet_nid_t src_nid, struct lnet_msg *msg, lnet_nid_t rtr_nid)
+{
+       lnet_nid_t              dst_nid = msg->msg_target.nid;
+       int                     rc;
+
+       /*
+        * NB: rtr_nid is set to LNET_NID_ANY for all current use-cases,
+        * but we might want to use pre-determined router for ACK/REPLY
+        * in the future
+        */
+       /* NB: ni != NULL == interface pre-determined (ACK/REPLY) */
+       LASSERT (msg->msg_txpeer == NULL);
+       LASSERT (!msg->msg_sending);
+       LASSERT (!msg->msg_target_is_router);
+       LASSERT (!msg->msg_receiving);
+
+       msg->msg_sending = 1;
+
+       LASSERT(!msg->msg_tx_committed);
+
+       rc = lnet_select_pathway(src_nid, dst_nid, msg, rtr_nid);
        if (rc < 0)
                return rc;
 
        if (rc == LNET_CREDIT_OK)
-               lnet_ni_send(src_ni, msg);
+               lnet_ni_send(msg->msg_txni, msg);
 
-       return 0; /* rc == LNET_CREDIT_OK or LNET_CREDIT_WAIT */
+       /* rc == LNET_CREDIT_OK or LNET_CREDIT_WAIT or LNET_DC_WAIT */
+       return 0;
 }
 
 void
-lnet_drop_message(lnet_ni_t *ni, int cpt, void *private, unsigned int nob)
+lnet_drop_message(struct lnet_ni *ni, int cpt, void *private, unsigned int nob,
+                 __u32 msg_type)
 {
        lnet_net_lock(cpt);
+       lnet_incr_stats(&ni->ni_stats, msg_type, LNET_STATS_TYPE_DROP);
        the_lnet.ln_counters[cpt]->drop_count++;
        the_lnet.ln_counters[cpt]->drop_length += nob;
        lnet_net_unlock(cpt);
@@ -1415,9 +2152,9 @@ lnet_drop_message(lnet_ni_t *ni, int cpt, void *private, unsigned int nob)
 }
 
 static void
-lnet_recv_put(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_recv_put(struct lnet_ni *ni, struct lnet_msg *msg)
 {
-       lnet_hdr_t      *hdr = &msg->msg_hdr;
+       struct lnet_hdr *hdr = &msg->msg_hdr;
 
        if (msg->msg_wanted != 0)
                lnet_setpayloadbuffer(msg);
@@ -1434,9 +2171,9 @@ lnet_recv_put(lnet_ni_t *ni, lnet_msg_t *msg)
 }
 
 static int
-lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_parse_put(struct lnet_ni *ni, struct lnet_msg *msg)
 {
-       lnet_hdr_t              *hdr = &msg->msg_hdr;
+       struct lnet_hdr         *hdr = &msg->msg_hdr;
        struct lnet_match_info  info;
        int                     rc;
        bool                    ready_delay;
@@ -1446,15 +2183,17 @@ lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg)
        hdr->msg.put.ptl_index  = le32_to_cpu(hdr->msg.put.ptl_index);
        hdr->msg.put.offset     = le32_to_cpu(hdr->msg.put.offset);
 
-       info.mi_id.nid  = hdr->src_nid;
+       /* Primary peer NID. */
+       info.mi_id.nid  = msg->msg_initiator;
        info.mi_id.pid  = hdr->src_pid;
        info.mi_opc     = LNET_MD_OP_PUT;
        info.mi_portal  = hdr->msg.put.ptl_index;
        info.mi_rlength = hdr->payload_length;
        info.mi_roffset = hdr->msg.put.offset;
        info.mi_mbits   = hdr->msg.put.match_bits;
+       info.mi_cpt     = lnet_cpt_of_nid(msg->msg_rxpeer->lpni_nid, ni);
 
-       msg->msg_rx_ready_delay = ni->ni_lnd->lnd_eager_recv == NULL;
+       msg->msg_rx_ready_delay = ni->ni_net->net_lnd->lnd_eager_recv == NULL;
        ready_delay = msg->msg_rx_ready_delay;
 
  again:
@@ -1491,12 +2230,13 @@ lnet_parse_put(lnet_ni_t *ni, lnet_msg_t *msg)
 }
 
 static int
-lnet_parse_get(lnet_ni_t *ni, lnet_msg_t *msg, int rdma_get)
+lnet_parse_get(struct lnet_ni *ni, struct lnet_msg *msg, int rdma_get)
 {
-       struct lnet_match_info  info;
-       lnet_hdr_t              *hdr = &msg->msg_hdr;
+       struct lnet_match_info info;
+       struct lnet_hdr *hdr = &msg->msg_hdr;
+       struct lnet_process_id source_id;
        struct lnet_handle_wire reply_wmd;
-       int                     rc;
+       int rc;
 
        /* Convert get fields to host byte order */
        hdr->msg.get.match_bits   = le64_to_cpu(hdr->msg.get.match_bits);
@@ -1504,13 +2244,17 @@ lnet_parse_get(lnet_ni_t *ni, lnet_msg_t *msg, int rdma_get)
        hdr->msg.get.sink_length  = le32_to_cpu(hdr->msg.get.sink_length);
        hdr->msg.get.src_offset   = le32_to_cpu(hdr->msg.get.src_offset);
 
-       info.mi_id.nid  = hdr->src_nid;
+       source_id.nid = hdr->src_nid;
+       source_id.pid = hdr->src_pid;
+       /* Primary peer NID */
+       info.mi_id.nid  = msg->msg_initiator;
        info.mi_id.pid  = hdr->src_pid;
        info.mi_opc     = LNET_MD_OP_GET;
        info.mi_portal  = hdr->msg.get.ptl_index;
        info.mi_rlength = hdr->msg.get.sink_length;
        info.mi_roffset = hdr->msg.get.src_offset;
        info.mi_mbits   = hdr->msg.get.match_bits;
+       info.mi_cpt     = lnet_cpt_of_nid(msg->msg_rxpeer->lpni_nid, ni);
 
        rc = lnet_ptl_match_md(&info, msg);
        if (rc == LNET_MATCHMD_DROP) {
@@ -1527,7 +2271,7 @@ lnet_parse_get(lnet_ni_t *ni, lnet_msg_t *msg, int rdma_get)
 
        reply_wmd = hdr->msg.get.return_wmd;
 
-       lnet_prep_send(msg, LNET_MSG_REPLY, info.mi_id,
+       lnet_prep_send(msg, LNET_MSG_REPLY, source_id,
                       msg->msg_offset, msg->msg_wanted);
 
        msg->msg_hdr.msg.reply.dst_wmd = reply_wmd;
@@ -1549,19 +2293,19 @@ lnet_parse_get(lnet_ni_t *ni, lnet_msg_t *msg, int rdma_get)
                       libcfs_nid2str(ni->ni_nid),
                       libcfs_id2str(info.mi_id), rc);
 
-               lnet_finalize(ni, msg, rc);
+               lnet_finalize(msg, rc);
        }
 
        return 0;
 }
 
 static int
-lnet_parse_reply(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_parse_reply(struct lnet_ni *ni, struct lnet_msg *msg)
 {
        void             *private = msg->msg_private;
-       lnet_hdr_t       *hdr = &msg->msg_hdr;
-       lnet_process_id_t src = {0};
-       lnet_libmd_t     *md;
+       struct lnet_hdr  *hdr = &msg->msg_hdr;
+       struct lnet_process_id src = {0};
+       struct lnet_libmd        *md;
        int               rlength;
        int               mlength;
        int                     cpt;
@@ -1623,11 +2367,11 @@ lnet_parse_reply(lnet_ni_t *ni, lnet_msg_t *msg)
 }
 
 static int
-lnet_parse_ack(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_parse_ack(struct lnet_ni *ni, struct lnet_msg *msg)
 {
-       lnet_hdr_t       *hdr = &msg->msg_hdr;
-       lnet_process_id_t src = {0};
-       lnet_libmd_t     *md;
+       struct lnet_hdr  *hdr = &msg->msg_hdr;
+       struct lnet_process_id src = {0};
+       struct lnet_libmd        *md;
        int                     cpt;
 
        src.nid = hdr->src_nid;
@@ -1678,16 +2422,16 @@ lnet_parse_ack(lnet_ni_t *ni, lnet_msg_t *msg)
  * \retval -ve                 error code
  */
 int
-lnet_parse_forward_locked(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_parse_forward_locked(struct lnet_ni *ni, struct lnet_msg *msg)
 {
        int     rc = 0;
 
        if (!the_lnet.ln_routing)
                return -ECANCELED;
 
-       if (msg->msg_rxpeer->lp_rtrcredits <= 0 ||
+       if (msg->msg_rxpeer->lpni_rtrcredits <= 0 ||
            lnet_msg2bufpool(msg)->rbp_credits <= 0) {
-               if (ni->ni_lnd->lnd_eager_recv == NULL) {
+               if (ni->ni_net->net_lnd->lnd_eager_recv == NULL) {
                        msg->msg_rx_ready_delay = 1;
                } else {
                        lnet_net_unlock(msg->msg_rx_cpt);
@@ -1702,7 +2446,7 @@ lnet_parse_forward_locked(lnet_ni_t *ni, lnet_msg_t *msg)
 }
 
 int
-lnet_parse_local(lnet_ni_t *ni, lnet_msg_t *msg)
+lnet_parse_local(struct lnet_ni *ni, struct lnet_msg *msg)
 {
        int     rc;
 
@@ -1748,18 +2492,18 @@ lnet_msgtyp2str (int type)
 }
 
 void
-lnet_print_hdr(lnet_hdr_t * hdr)
+lnet_print_hdr(struct lnet_hdr *hdr)
 {
-       lnet_process_id_t src = {0};
-       lnet_process_id_t dst = {0};
+       struct lnet_process_id src = {
+               .nid = hdr->src_nid,
+               .pid = hdr->src_pid,
+       };
+       struct lnet_process_id dst = {
+               .nid = hdr->dest_nid,
+               .pid = hdr->dest_pid,
+       };
        char *type_str = lnet_msgtyp2str(hdr->type);
 
-       src.nid = hdr->src_nid;
-       src.pid = hdr->src_pid;
-
-       dst.nid = hdr->dest_nid;
-       dst.pid = hdr->dest_pid;
-
        CWARN("P3 Header at %p of type %s\n", hdr, type_str);
        CWARN("    From %s\n", libcfs_id2str(src));
        CWARN("    To   %s\n", libcfs_id2str(dst));
@@ -1810,7 +2554,7 @@ lnet_print_hdr(lnet_hdr_t * hdr)
 }
 
 int
-lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
+lnet_parse(struct lnet_ni *ni, struct lnet_hdr *hdr, lnet_nid_t from_nid,
           void *private, int rdma_req)
 {
        int             rc = 0;
@@ -1820,8 +2564,9 @@ lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
        lnet_pid_t     dest_pid;
        lnet_nid_t     dest_nid;
        lnet_nid_t     src_nid;
-       __u32          payload_length;
-       __u32          type;
+       struct lnet_peer_ni *lpni;
+       __u32          payload_length;
+       __u32          type;
 
        LASSERT (!in_interrupt ());
 
@@ -1832,7 +2577,14 @@ lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
        payload_length = le32_to_cpu(hdr->payload_length);
 
        for_me = (ni->ni_nid == dest_nid);
-       cpt = lnet_cpt_of_nid(from_nid);
+       cpt = lnet_cpt_of_nid(from_nid, ni);
+
+       CDEBUG(D_NET, "TRACE: %s(%s) <- %s : %s - %s\n",
+               libcfs_nid2str(dest_nid),
+               libcfs_nid2str(ni->ni_nid),
+               libcfs_nid2str(src_nid),
+               lnet_msgtyp2str(type),
+               (for_me) ? "for me" : "routed");
 
        switch (type) {
        case LNET_MSG_ACK:
@@ -1981,19 +2733,24 @@ lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
        }
 
        lnet_net_lock(cpt);
-       rc = lnet_nid2peer_locked(&msg->msg_rxpeer, from_nid, cpt);
-       if (rc != 0) {
+       lpni = lnet_nid2peerni_locked(from_nid, ni->ni_nid, cpt);
+       if (IS_ERR(lpni)) {
                lnet_net_unlock(cpt);
                CERROR("%s, src %s: Dropping %s "
-                      "(error %d looking up sender)\n",
+                      "(error %ld looking up sender)\n",
                       libcfs_nid2str(from_nid), libcfs_nid2str(src_nid),
-                      lnet_msgtyp2str(type), rc);
+                      lnet_msgtyp2str(type), PTR_ERR(lpni));
                lnet_msg_free(msg);
                if (rc == -ESHUTDOWN)
                        /* We are shutting down.  Don't do anything more */
                        return 0;
                goto drop;
        }
+       msg->msg_rxpeer = lpni;
+       msg->msg_rxni = ni;
+       lnet_ni_addref_locked(ni, cpt);
+       /* Multi-Rail: Primary NID of source. */
+       msg->msg_initiator = lnet_peer_primary_nid_locked(src_nid);
 
        if (lnet_isrouter(msg->msg_rxpeer)) {
                lnet_peer_set_alive(msg->msg_rxpeer);
@@ -2040,10 +2797,10 @@ lnet_parse(lnet_ni_t *ni, lnet_hdr_t *hdr, lnet_nid_t from_nid,
 
  free_drop:
        LASSERT(msg->msg_md == NULL);
-       lnet_finalize(ni, msg, rc);
+       lnet_finalize(msg, rc);
 
  drop:
-       lnet_drop_message(ni, cpt, private, payload_length);
+       lnet_drop_message(ni, cpt, private, payload_length, type);
        return 0;
 }
 EXPORT_SYMBOL(lnet_parse);
@@ -2052,10 +2809,10 @@ void
 lnet_drop_delayed_msg_list(struct list_head *head, char *reason)
 {
        while (!list_empty(head)) {
-               lnet_process_id_t       id = {0};
-               lnet_msg_t              *msg;
+               struct lnet_process_id id = {0};
+               struct lnet_msg *msg;
 
-               msg = list_entry(head->next, lnet_msg_t, msg_list);
+               msg = list_entry(head->next, struct lnet_msg, msg_list);
                list_del(&msg->msg_list);
 
                id.nid = msg->msg_hdr.src_nid;
@@ -2078,15 +2835,15 @@ lnet_drop_delayed_msg_list(struct list_head *head, char *reason)
                 * called lnet_drop_message(), so I just hang onto msg as well
                 * until that's done */
 
-               lnet_drop_message(msg->msg_rxpeer->lp_ni,
-                                 msg->msg_rxpeer->lp_cpt,
-                                 msg->msg_private, msg->msg_len);
+               lnet_drop_message(msg->msg_rxni, msg->msg_rx_cpt,
+                                 msg->msg_private, msg->msg_len,
+                                 msg->msg_type);
                /*
                 * NB: message will not generate event because w/o attached MD,
                 * but we still should give error code so lnet_msg_decommit()
                 * can skip counters operations and other checks.
                 */
-               lnet_finalize(msg->msg_rxpeer->lp_ni, msg, -ENOENT);
+               lnet_finalize(msg, -ENOENT);
        }
 }
 
@@ -2094,10 +2851,10 @@ void
 lnet_recv_delayed_msg_list(struct list_head *head)
 {
        while (!list_empty(head)) {
-               lnet_msg_t        *msg;
-               lnet_process_id_t  id;
+               struct lnet_msg *msg;
+               struct lnet_process_id id;
 
-               msg = list_entry(head->next, lnet_msg_t, msg_list);
+               msg = list_entry(head->next, struct lnet_msg, msg_list);
                list_del(&msg->msg_list);
 
                /* md won't disappear under me, since each msg
@@ -2109,6 +2866,7 @@ lnet_recv_delayed_msg_list(struct list_head *head)
                LASSERT(msg->msg_rx_delayed);
                LASSERT(msg->msg_md != NULL);
                LASSERT(msg->msg_rxpeer != NULL);
+               LASSERT(msg->msg_rxni != NULL);
                LASSERT(msg->msg_hdr.type == LNET_MSG_PUT);
 
                CDEBUG(D_NET, "Resuming delayed PUT from %s portal %d "
@@ -2118,7 +2876,7 @@ lnet_recv_delayed_msg_list(struct list_head *head)
                        msg->msg_hdr.msg.put.offset,
                        msg->msg_hdr.payload_length);
 
-               lnet_recv_put(msg->msg_rxpeer->lp_ni, msg);
+               lnet_recv_put(msg->msg_rxni, msg);
        }
 }
 
@@ -2164,11 +2922,11 @@ lnet_recv_delayed_msg_list(struct list_head *head)
  * \retval -ENOMEM Memory allocation failure.
  * \retval -ENOENT Invalid MD object.
  *
- * \see lnet_event_t::hdr_data and lnet_event_kind_t.
+ * \see struct lnet_event::hdr_data and lnet_event_kind_t.
  */
 int
-LNetPut(lnet_nid_t self, lnet_handle_md_t mdh, lnet_ack_req_t ack,
-       lnet_process_id_t target, unsigned int portal,
+LNetPut(lnet_nid_t self, struct lnet_handle_md mdh, enum lnet_ack_req ack,
+       struct lnet_process_id target, unsigned int portal,
        __u64 match_bits, unsigned int offset,
        __u64 hdr_data)
 {
@@ -2188,7 +2946,7 @@ LNetPut(lnet_nid_t self, lnet_handle_md_t mdh, lnet_ack_req_t ack,
 
        msg = lnet_msg_alloc();
        if (msg == NULL) {
-               CERROR("Dropping PUT to %s: ENOMEM on lnet_msg_t\n",
+               CERROR("Dropping PUT to %s: ENOMEM on struct lnet_msg\n",
                       libcfs_id2str(target));
                return -ENOMEM;
        }
@@ -2243,7 +3001,7 @@ LNetPut(lnet_nid_t self, lnet_handle_md_t mdh, lnet_ack_req_t ack,
        if (rc != 0) {
                CNETERR("Error sending PUT to %s: %d\n",
                        libcfs_id2str(target), rc);
-               lnet_finalize(NULL, msg, rc);
+               lnet_finalize(msg, rc);
        }
 
        /* completion will be signalled by an event */
@@ -2251,20 +3009,21 @@ LNetPut(lnet_nid_t self, lnet_handle_md_t mdh, lnet_ack_req_t ack,
 }
 EXPORT_SYMBOL(LNetPut);
 
-lnet_msg_t *
-lnet_create_reply_msg (lnet_ni_t *ni, lnet_msg_t *getmsg)
+/*
+ * The LND can DMA direct to the GET md (i.e. no REPLY msg).  This
+ * returns a msg for the LND to pass to lnet_finalize() when the sink
+ * data has been received.
+ *
+ * CAVEAT EMPTOR: 'getmsg' is the original GET, which is freed when
+ * lnet_finalize() is called on it, so the LND must call this first
+ */
+struct lnet_msg *
+lnet_create_reply_msg(struct lnet_ni *ni, struct lnet_msg *getmsg)
 {
-       /* The LND can DMA direct to the GET md (i.e. no REPLY msg).  This
-        * returns a msg for the LND to pass to lnet_finalize() when the sink
-        * data has been received.
-        *
-        * CAVEAT EMPTOR: 'getmsg' is the original GET, which is freed when
-        * lnet_finalize() is called on it, so the LND must call this first */
-
-       struct lnet_msg         *msg = lnet_msg_alloc();
-       struct lnet_libmd       *getmd = getmsg->msg_md;
-       lnet_process_id_t       peer_id = getmsg->msg_target;
-       int                     cpt;
+       struct lnet_msg *msg = lnet_msg_alloc();
+       struct lnet_libmd *getmd = getmsg->msg_md;
+       struct lnet_process_id peer_id = getmsg->msg_target;
+       int cpt;
 
        LASSERT(!getmsg->msg_target_is_router);
        LASSERT(!getmsg->msg_routing);
@@ -2294,6 +3053,7 @@ lnet_create_reply_msg (lnet_ni_t *ni, lnet_msg_t *getmsg)
               libcfs_nid2str(ni->ni_nid), libcfs_id2str(peer_id), getmd);
 
        /* setup information for lnet_build_msg_event */
+       msg->msg_initiator = getmsg->msg_txpeer->lpni_peer_net->lpn_peer->lp_primary_nid;
        msg->msg_from = peer_id.nid;
        msg->msg_type = LNET_MSG_GET; /* flag this msg as an "optimized" GET */
        msg->msg_hdr.src_nid = peer_id.nid;
@@ -2303,7 +3063,7 @@ lnet_create_reply_msg (lnet_ni_t *ni, lnet_msg_t *getmsg)
        lnet_msg_attach_md(msg, getmd, getmd->md_offset, getmd->md_length);
        lnet_res_unlock(cpt);
 
-       cpt = lnet_cpt_of_nid(peer_id.nid);
+       cpt = lnet_cpt_of_nid(peer_id.nid, ni);
 
        lnet_net_lock(cpt);
        lnet_msg_commit(msg, cpt);
@@ -2314,9 +3074,10 @@ lnet_create_reply_msg (lnet_ni_t *ni, lnet_msg_t *getmsg)
        return msg;
 
  drop:
-       cpt = lnet_cpt_of_nid(peer_id.nid);
+       cpt = lnet_cpt_of_nid(peer_id.nid, ni);
 
        lnet_net_lock(cpt);
+       lnet_incr_stats(&ni->ni_stats, LNET_MSG_GET, LNET_STATS_TYPE_DROP);
        the_lnet.ln_counters[cpt]->drop_count++;
        the_lnet.ln_counters[cpt]->drop_length += getmd->md_length;
        lnet_net_unlock(cpt);
@@ -2329,7 +3090,8 @@ lnet_create_reply_msg (lnet_ni_t *ni, lnet_msg_t *getmsg)
 EXPORT_SYMBOL(lnet_create_reply_msg);
 
 void
-lnet_set_reply_msg_len(lnet_ni_t *ni, lnet_msg_t *reply, unsigned int len)
+lnet_set_reply_msg_len(struct lnet_ni *ni, struct lnet_msg *reply,
+                      unsigned int len)
 {
        /* Set the REPLY length, now the RDMA that elides the REPLY message has
         * completed and I know it. */
@@ -2366,8 +3128,8 @@ EXPORT_SYMBOL(lnet_set_reply_msg_len);
  * \retval -ENOENT Invalid MD object.
  */
 int
-LNetGet(lnet_nid_t self, lnet_handle_md_t mdh,
-       lnet_process_id_t target, unsigned int portal,
+LNetGet(lnet_nid_t self, struct lnet_handle_md mdh,
+       struct lnet_process_id target, unsigned int portal,
        __u64 match_bits, unsigned int offset)
 {
        struct lnet_msg         *msg;
@@ -2387,7 +3149,7 @@ LNetGet(lnet_nid_t self, lnet_handle_md_t mdh,
 
        msg = lnet_msg_alloc();
        if (msg == NULL) {
-               CERROR("Dropping GET to %s: ENOMEM on lnet_msg_t\n",
+               CERROR("Dropping GET to %s: ENOMEM on struct lnet_msg\n",
                       libcfs_id2str(target));
                return -ENOMEM;
        }
@@ -2435,7 +3197,7 @@ LNetGet(lnet_nid_t self, lnet_handle_md_t mdh,
        if (rc < 0) {
                CNETERR("Error sending GET to %s: %d\n",
                        libcfs_id2str(target), rc);
-               lnet_finalize(NULL, msg, rc);
+               lnet_finalize(msg, rc);
        }
 
        /* completion will be signalled by an event */
@@ -2461,8 +3223,8 @@ int
 LNetDist(lnet_nid_t dstnid, lnet_nid_t *srcnidp, __u32 *orderp)
 {
        struct list_head        *e;
-       struct lnet_ni          *ni;
-       lnet_remotenet_t        *rnet;
+       struct lnet_ni *ni = NULL;
+       struct lnet_remotenet *rnet;
        __u32                   dstnet = LNET_NIDNET(dstnid);
        int                     hops;
        int                     cpt;
@@ -2478,9 +3240,7 @@ LNetDist(lnet_nid_t dstnid, lnet_nid_t *srcnidp, __u32 *orderp)
 
        cpt = lnet_net_lock_current();
 
-       list_for_each(e, &the_lnet.ln_nis) {
-               ni = list_entry(e, lnet_ni_t, ni_list);
-
+       while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
                if (ni->ni_nid == dstnid) {
                        if (srcnidp != NULL)
                                *srcnidp = dstnid;
@@ -2516,11 +3276,11 @@ LNetDist(lnet_nid_t dstnid, lnet_nid_t *srcnidp, __u32 *orderp)
 
        rn_list = lnet_net2rnethash(dstnet);
        list_for_each(e, rn_list) {
-               rnet = list_entry(e, lnet_remotenet_t, lrn_list);
+               rnet = list_entry(e, struct lnet_remotenet, lrn_list);
 
                if (rnet->lrn_net == dstnet) {
-                       lnet_route_t *route;
-                       lnet_route_t *shortest = NULL;
+                       struct lnet_route *route;
+                       struct lnet_route *shortest = NULL;
                        __u32 shortest_hops = LNET_UNDEFINED_HOPS;
                        __u32 route_hops;
 
@@ -2540,8 +3300,12 @@ LNetDist(lnet_nid_t dstnid, lnet_nid_t *srcnidp, __u32 *orderp)
 
                        LASSERT(shortest != NULL);
                        hops = shortest_hops;
-                       if (srcnidp != NULL)
-                               *srcnidp = shortest->lr_gateway->lp_ni->ni_nid;
+                       if (srcnidp != NULL) {
+                               ni = lnet_get_next_ni_locked(
+                                       shortest->lr_gateway->lpni_net,
+                                       NULL);
+                               *srcnidp = ni->ni_nid;
+                       }
                        if (orderp != NULL)
                                *orderp = order;
                        lnet_net_unlock(cpt);