Whamcloud - gitweb
LU-6068 misc: update old URLs to hpdd.intel.com
[fs/lustre-release.git] / lnet / klnds / socklnd / socklnd_cb.c
index 85e687a..7879b47 100644 (file)
@@ -1,14 +1,14 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  *
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2011, 2014, Intel Corporation.
  *
  *   Author: Zach Brown <zab@zabbo.net>
  *   Author: Peter J. Braam <braam@clusterfs.com>
  *   Author: Phil Schwan <phil@clusterfs.com>
  *   Author: Eric Barton <eric@bartonsoftware.com>
  *
- *   This file is part of Portals, http://www.sf.net/projects/sandiaportals/
+ *   This file is part of Lustre, https://wiki.hpdd.intel.com/
  *
  *   Portals is free software; you can redistribute it and/or
  *   modify it under the terms of version 2 of the GNU General Public
 #include "socklnd.h"
 
 ksock_tx_t *
-ksocknal_alloc_tx (int size)
+ksocknal_alloc_tx(int type, int size)
 {
-        ksock_tx_t *tx = NULL;
+       ksock_tx_t *tx = NULL;
 
-        if (size == KSOCK_NOOP_TX_SIZE) {
-                /* searching for a noop tx in free list */
-                spin_lock(&ksocknal_data.ksnd_tx_lock);
+       if (type == KSOCK_MSG_NOOP) {
+               LASSERT(size == KSOCK_NOOP_TX_SIZE);
 
-                if (!list_empty(&ksocknal_data.ksnd_idle_noop_txs)) {
-                        tx = list_entry(ksocknal_data.ksnd_idle_noop_txs.next,
-                                        ksock_tx_t, tx_list);
-                        LASSERT(tx->tx_desc_size == size);
-                        list_del(&tx->tx_list);
-                }
+               /* searching for a noop tx in free list */
+               spin_lock(&ksocknal_data.ksnd_tx_lock);
 
-                spin_unlock(&ksocknal_data.ksnd_tx_lock);
+               if (!list_empty(&ksocknal_data.ksnd_idle_noop_txs)) {
+                       tx = list_entry(ksocknal_data.ksnd_idle_noop_txs. \
+                                           next, ksock_tx_t, tx_list);
+                       LASSERT(tx->tx_desc_size == size);
+                       list_del(&tx->tx_list);
+               }
+
+               spin_unlock(&ksocknal_data.ksnd_tx_lock);
         }
 
         if (tx == NULL)
@@ -51,40 +53,61 @@ ksocknal_alloc_tx (int size)
         if (tx == NULL)
                 return NULL;
 
-        atomic_set(&tx->tx_refcount, 1);
-        tx->tx_desc_size = size;
-        atomic_inc(&ksocknal_data.ksnd_nactive_txs);
+       atomic_set(&tx->tx_refcount, 1);
+       tx->tx_zc_aborted = 0;
+       tx->tx_zc_capable = 0;
+       tx->tx_zc_checked = 0;
+       tx->tx_desc_size  = size;
 
-        return tx;
+       atomic_inc(&ksocknal_data.ksnd_nactive_txs);
+
+       return tx;
 }
 
-void
-ksocknal_free_tx (ksock_tx_t *tx)
+ksock_tx_t *
+ksocknal_alloc_tx_noop(__u64 cookie, int nonblk)
 {
-        atomic_dec(&ksocknal_data.ksnd_nactive_txs);
+        ksock_tx_t *tx;
+
+        tx = ksocknal_alloc_tx(KSOCK_MSG_NOOP, KSOCK_NOOP_TX_SIZE);
+        if (tx == NULL) {
+                CERROR("Can't allocate noop tx desc\n");
+                return NULL;
+        }
 
-        if (tx->tx_desc_size == KSOCK_NOOP_TX_SIZE) {
-                /* it's a noop tx */
-                spin_lock(&ksocknal_data.ksnd_tx_lock);
+        tx->tx_conn     = NULL;
+        tx->tx_lnetmsg  = NULL;
+        tx->tx_kiov     = NULL;
+        tx->tx_nkiov    = 0;
+        tx->tx_iov      = tx->tx_frags.virt.iov;
+        tx->tx_niov     = 1;
+        tx->tx_nonblk   = nonblk;
 
-                list_add(&tx->tx_list, &ksocknal_data.ksnd_idle_noop_txs);
+        socklnd_init_msg(&tx->tx_msg, KSOCK_MSG_NOOP);
+        tx->tx_msg.ksm_zc_cookies[1] = cookie;
 
-                spin_unlock(&ksocknal_data.ksnd_tx_lock);
-        } else {
-                LIBCFS_FREE(tx, tx->tx_desc_size);
-        }
+        return tx;
 }
 
+
 void
-ksocknal_init_msg(ksock_msg_t *msg, int type)
+ksocknal_free_tx (ksock_tx_t *tx)
 {
-        msg->ksm_type           = type;
-        msg->ksm_csum           = 0;
-        msg->ksm_zc_req_cookie  = 0;
-        msg->ksm_zc_ack_cookie  = 0;
+       atomic_dec(&ksocknal_data.ksnd_nactive_txs);
+
+       if (tx->tx_lnetmsg == NULL && tx->tx_desc_size == KSOCK_NOOP_TX_SIZE) {
+               /* it's a noop tx */
+               spin_lock(&ksocknal_data.ksnd_tx_lock);
+
+               list_add(&tx->tx_list, &ksocknal_data.ksnd_idle_noop_txs);
+
+               spin_unlock(&ksocknal_data.ksnd_tx_lock);
+       } else {
+               LIBCFS_FREE(tx, tx->tx_desc_size);
+       }
 }
 
-int
+static int
 ksocknal_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
 {
         struct iovec  *iov = tx->tx_iov;
@@ -107,8 +130,8 @@ ksocknal_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
         do {
                 LASSERT (tx->tx_niov > 0);
 
-                if (nob < iov->iov_len) {
-                        iov->iov_base = (void *)(((unsigned long)(iov->iov_base)) + nob);
+                if (nob < (int) iov->iov_len) {
+                       iov->iov_base += nob;
                         iov->iov_len -= nob;
                         return (rc);
                 }
@@ -121,7 +144,7 @@ ksocknal_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
         return (rc);
 }
 
-int
+static int
 ksocknal_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
 {
         lnet_kiov_t    *kiov = tx->tx_kiov;
@@ -145,13 +168,13 @@ ksocknal_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
         do {
                 LASSERT(tx->tx_nkiov > 0);
 
-                if (nob < kiov->kiov_len) {
+                if (nob < (int)kiov->kiov_len) {
                         kiov->kiov_offset += nob;
                         kiov->kiov_len -= nob;
                         return rc;
                 }
 
-                nob -= kiov->kiov_len;
+                nob -= (int)kiov->kiov_len;
                 tx->tx_kiov = ++kiov;
                 tx->tx_nkiov--;
         } while (nob != 0);
@@ -159,17 +182,18 @@ ksocknal_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
         return (rc);
 }
 
-int
-ksocknal_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
+static int
+ksocknal_transmit(ksock_conn_t *conn, ksock_tx_t *tx)
 {
-        int      rc;
-        int      bufnob;
+       int     rc;
+       int     bufnob;
 
-        if (ksocknal_data.ksnd_stall_tx != 0) {
-                cfs_pause(cfs_time_seconds(ksocknal_data.ksnd_stall_tx));
-        }
+       if (ksocknal_data.ksnd_stall_tx != 0) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_tx));
+       }
 
-        LASSERT (tx->tx_resid != 0);
+       LASSERT(tx->tx_resid != 0);
 
         rc = ksocknal_connsock_addref(conn);
         if (rc != 0) {
@@ -188,53 +212,34 @@ ksocknal_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
                         rc = ksocknal_send_kiov (conn, tx);
                 }
 
-                bufnob = SOCK_WMEM_QUEUED(conn->ksnc_sock);
+               bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
                 if (rc > 0)                     /* sent something? */
                         conn->ksnc_tx_bufnob += rc; /* account it */
 
-                if (bufnob < conn->ksnc_tx_bufnob) {
-                        /* allocated send buffer bytes < computed; infer
-                         * something got ACKed */
-                        conn->ksnc_tx_deadline =
-                                cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-                        conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
-                        conn->ksnc_tx_bufnob = bufnob;
-                        mb();
-                }
+               if (bufnob < conn->ksnc_tx_bufnob) {
+                       /* allocated send buffer bytes < computed; infer
+                        * something got ACKed */
+                       conn->ksnc_tx_deadline =
+                               cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+                       conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
+                       conn->ksnc_tx_bufnob = bufnob;
+                       smp_mb();
+               }
 
-                if (rc <= 0) { /* Didn't write anything? */
-                        ksock_sched_t *sched;
+               if (rc <= 0) { /* Didn't write anything? */
 
                         if (rc == 0) /* some stacks return 0 instead of -EAGAIN */
                                 rc = -EAGAIN;
 
-                        if (rc != -EAGAIN)
-                                break;
-
                         /* Check if EAGAIN is due to memory pressure */
-
-                        sched = conn->ksnc_scheduler;
-                        spin_lock_bh (&sched->kss_lock);
-
-                        if (!SOCK_TEST_NOSPACE(conn->ksnc_sock) &&
-                            !conn->ksnc_tx_ready) {
-                                /* SOCK_NOSPACE is set when the socket fills
-                                 * and cleared in the write_space callback
-                                 * (which also sets ksnc_tx_ready).  If
-                                 * SOCK_NOSPACE and ksnc_tx_ready are BOTH
-                                 * zero, I didn't fill the socket and
-                                 * write_space won't reschedule me, so I
-                                 * return -ENOMEM to get my caller to retry
-                                 * after a timeout */
+                        if(rc == -EAGAIN && ksocknal_lib_memory_pressure(conn))
                                 rc = -ENOMEM;
-                        }
 
-                        spin_unlock_bh (&sched->kss_lock);
                         break;
                 }
 
                 /* socket's wmem_queued now includes 'rc' bytes */
-                atomic_sub (rc, &conn->ksnc_tx_nob);
+               atomic_sub (rc, &conn->ksnc_tx_nob);
                 rc = 0;
 
         } while (tx->tx_resid != 0);
@@ -243,7 +248,7 @@ ksocknal_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
         return (rc);
 }
 
-int
+static int
 ksocknal_recv_iov (ksock_conn_t *conn)
 {
         struct iovec *iov = conn->ksnc_rx_iov;
@@ -252,7 +257,7 @@ ksocknal_recv_iov (ksock_conn_t *conn)
 
         LASSERT (conn->ksnc_rx_niov > 0);
 
-        /* Never touch conn->ksnc_rx_iov or change connection 
+       /* Never touch conn->ksnc_rx_iov or change connection
          * status inside ksocknal_lib_recv_iov */
         rc = ksocknal_lib_recv_iov(conn);
 
@@ -262,21 +267,21 @@ ksocknal_recv_iov (ksock_conn_t *conn)
         /* received something... */
         nob = rc;
 
-        conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
-        conn->ksnc_rx_deadline =
-                cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-        mb();                           /* order with setting rx_started */
-        conn->ksnc_rx_started = 1;
+       conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
+       conn->ksnc_rx_deadline =
+               cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+       smp_mb();                       /* order with setting rx_started */
+       conn->ksnc_rx_started = 1;
 
-        conn->ksnc_rx_nob_wanted -= nob;
-        conn->ksnc_rx_nob_left -= nob;
+       conn->ksnc_rx_nob_wanted -= nob;
+       conn->ksnc_rx_nob_left -= nob;
 
         do {
                 LASSERT (conn->ksnc_rx_niov > 0);
 
-                if (nob < iov->iov_len) {
+                if (nob < (int)iov->iov_len) {
                         iov->iov_len -= nob;
-                        iov->iov_base = (void *)(((unsigned long)iov->iov_base) + nob);
+                       iov->iov_base += nob;
                         return (-EAGAIN);
                 }
 
@@ -288,7 +293,7 @@ ksocknal_recv_iov (ksock_conn_t *conn)
         return (rc);
 }
 
-int
+static int
 ksocknal_recv_kiov (ksock_conn_t *conn)
 {
         lnet_kiov_t   *kiov = conn->ksnc_rx_kiov;
@@ -296,7 +301,7 @@ ksocknal_recv_kiov (ksock_conn_t *conn)
         int     rc;
         LASSERT (conn->ksnc_rx_nkiov > 0);
 
-        /* Never touch conn->ksnc_rx_kiov or change connection 
+       /* Never touch conn->ksnc_rx_kiov or change connection
          * status inside ksocknal_lib_recv_iov */
         rc = ksocknal_lib_recv_kiov(conn);
 
@@ -306,19 +311,19 @@ ksocknal_recv_kiov (ksock_conn_t *conn)
         /* received something... */
         nob = rc;
 
-        conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
-        conn->ksnc_rx_deadline =
-                cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-        mb();                           /* order with setting rx_started */
-        conn->ksnc_rx_started = 1;
+       conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
+       conn->ksnc_rx_deadline =
+               cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+       smp_mb();                       /* order with setting rx_started */
+       conn->ksnc_rx_started = 1;
 
-        conn->ksnc_rx_nob_wanted -= nob;
-        conn->ksnc_rx_nob_left -= nob;
+       conn->ksnc_rx_nob_wanted -= nob;
+       conn->ksnc_rx_nob_left -= nob;
 
         do {
                 LASSERT (conn->ksnc_rx_nkiov > 0);
 
-                if (nob < kiov->kiov_len) {
+                if (nob < (int) kiov->kiov_len) {
                         kiov->kiov_offset += nob;
                         kiov->kiov_len -= nob;
                         return -EAGAIN;
@@ -332,7 +337,7 @@ ksocknal_recv_kiov (ksock_conn_t *conn)
         return 1;
 }
 
-int
+static int
 ksocknal_receive (ksock_conn_t *conn)
 {
         /* Return 1 on success, 0 on EOF, < 0 on error.
@@ -341,9 +346,10 @@ ksocknal_receive (ksock_conn_t *conn)
         int     rc;
         ENTRY;
 
-        if (ksocknal_data.ksnd_stall_rx != 0) {
-                cfs_pause(cfs_time_seconds (ksocknal_data.ksnd_stall_rx));
-        }
+       if (ksocknal_data.ksnd_stall_rx != 0) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_rx));
+       }
 
         rc = ksocknal_connsock_addref(conn);
         if (rc != 0) {
@@ -384,7 +390,7 @@ void
 ksocknal_tx_done (lnet_ni_t *ni, ksock_tx_t *tx)
 {
         lnet_msg_t  *lnetmsg = tx->tx_lnetmsg;
-        int          rc = (tx->tx_resid == 0) ? 0 : -EIO;
+        int          rc = (tx->tx_resid == 0 && !tx->tx_zc_aborted) ? 0 : -EIO;
         ENTRY;
 
         LASSERT(ni != NULL || tx->tx_conn != NULL);
@@ -403,26 +409,26 @@ ksocknal_tx_done (lnet_ni_t *ni, ksock_tx_t *tx)
 }
 
 void
-ksocknal_txlist_done (lnet_ni_t *ni, struct list_head *txlist, int error)
+ksocknal_txlist_done(lnet_ni_t *ni, struct list_head *txlist, int error)
 {
         ksock_tx_t *tx;
 
-        while (!list_empty (txlist)) {
-                tx = list_entry (txlist->next, ksock_tx_t, tx_list);
+       while (!list_empty(txlist)) {
+               tx = list_entry(txlist->next, ksock_tx_t, tx_list);
 
                 if (error && tx->tx_lnetmsg != NULL) {
-                        CDEBUG (D_NETERROR, "Deleting packet type %d len %d %s->%s\n",
+                        CNETERR("Deleting packet type %d len %d %s->%s\n",
                                 le32_to_cpu (tx->tx_lnetmsg->msg_hdr.type),
                                 le32_to_cpu (tx->tx_lnetmsg->msg_hdr.payload_length),
                                 libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.src_nid)),
-                                libcfs_nid2str(le64_to_cpu (tx->tx_lnetmsg->msg_hdr.dest_nid)));
+                                libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.dest_nid)));
                 } else if (error) {
-                        CDEBUG (D_NETERROR, "Deleting noop packet\n");
+                        CNETERR("Deleting noop packet\n");
                 }
 
-                list_del (&tx->tx_list);
+               list_del(&tx->tx_list);
 
-                LASSERT (atomic_read(&tx->tx_refcount) == 1);
+               LASSERT (atomic_read(&tx->tx_refcount) == 1);
                 ksocknal_tx_done (ni, tx);
         }
 }
@@ -432,74 +438,78 @@ ksocknal_check_zc_req(ksock_tx_t *tx)
 {
         ksock_conn_t   *conn = tx->tx_conn;
         ksock_peer_t   *peer = conn->ksnc_peer;
-        lnet_kiov_t    *kiov = tx->tx_kiov;
-        int             nkiov = tx->tx_nkiov;
 
-        /* Set tx_msg.ksm_zc_req_cookie to a unique non-zero cookie and add tx
+        /* Set tx_msg.ksm_zc_cookies[0] to a unique non-zero cookie and add tx
          * to ksnp_zc_req_list if some fragment of this message should be sent
          * zero-copy.  Our peer will send an ACK containing this cookie when
          * she has received this message to tell us we can signal completion.
-         * tx_msg.ksm_zc_req_cookie remains non-zero while tx is on
+         * tx_msg.ksm_zc_cookies[0] remains non-zero while tx is on
          * ksnp_zc_req_list. */
+        LASSERT (tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
+        LASSERT (tx->tx_zc_capable);
 
-        if (conn->ksnc_proto != &ksocknal_protocol_v2x ||
-            !conn->ksnc_zc_capable)
-                return;
-
-        while (nkiov > 0) {
-                if (kiov->kiov_len >= *ksocknal_tunables.ksnd_zc_min_frag)
-                        break;
-                --nkiov;
-                ++kiov;
-        }
+        tx->tx_zc_checked = 1;
 
-        if (nkiov == 0)
+        if (conn->ksnc_proto == &ksocknal_protocol_v1x ||
+            !conn->ksnc_zc_capable)
                 return;
 
         /* assign cookie and queue tx to pending list, it will be released when
-         * a matching ack is received. See ksocknal_handle_zc_ack() */
+         * a matching ack is received. See ksocknal_handle_zcack() */
 
         ksocknal_tx_addref(tx);
 
-        spin_lock(&peer->ksnp_lock);
+       spin_lock(&peer->ksnp_lock);
+
+        /* ZC_REQ is going to be pinned to the peer */
+        tx->tx_deadline =
+                cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+
+        LASSERT (tx->tx_msg.ksm_zc_cookies[0] == 0);
+
+        tx->tx_msg.ksm_zc_cookies[0] = peer->ksnp_zc_next_cookie++;
 
-        LASSERT (tx->tx_msg.ksm_zc_req_cookie == 0);
-        tx->tx_msg.ksm_zc_req_cookie = peer->ksnp_zc_next_cookie++;
-        list_add_tail(&tx->tx_zc_list, &peer->ksnp_zc_req_list);
+        if (peer->ksnp_zc_next_cookie == 0)
+                peer->ksnp_zc_next_cookie = SOCKNAL_KEEPALIVE_PING + 1;
 
-        spin_unlock(&peer->ksnp_lock);
+       list_add_tail(&tx->tx_zc_list, &peer->ksnp_zc_req_list);
+
+       spin_unlock(&peer->ksnp_lock);
 }
 
 static void
-ksocknal_unzc_req(ksock_tx_t *tx)
+ksocknal_uncheck_zc_req(ksock_tx_t *tx)
 {
-        ksock_peer_t   *peer = tx->tx_conn->ksnc_peer;
+       ksock_peer_t   *peer = tx->tx_conn->ksnc_peer;
 
-        spin_lock(&peer->ksnp_lock);
+       LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
+       LASSERT(tx->tx_zc_capable);
 
-        if (tx->tx_msg.ksm_zc_req_cookie == 0) {
-                /* Not waiting for an ACK */
-                spin_unlock(&peer->ksnp_lock);
-                return;
-        }
+       tx->tx_zc_checked = 0;
+
+       spin_lock(&peer->ksnp_lock);
 
-        tx->tx_msg.ksm_zc_req_cookie = 0;
-        list_del(&tx->tx_zc_list);
+       if (tx->tx_msg.ksm_zc_cookies[0] == 0) {
+               /* Not waiting for an ACK */
+               spin_unlock(&peer->ksnp_lock);
+               return;
+       }
 
-        spin_unlock(&peer->ksnp_lock);
+       tx->tx_msg.ksm_zc_cookies[0] = 0;
+       list_del(&tx->tx_zc_list);
 
-        ksocknal_tx_decref(tx);
+       spin_unlock(&peer->ksnp_lock);
+
+       ksocknal_tx_decref(tx);
 }
 
-int
+static int
 ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
 {
         int            rc;
 
-        if (!tx->tx_checked_zc) {
-                tx->tx_checked_zc = 1;
+        if (tx->tx_zc_capable && !tx->tx_zc_checked)
                 ksocknal_check_zc_req(tx);
-        }
 
         rc = ksocknal_transmit (conn, tx);
 
@@ -521,23 +531,23 @@ ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
                 counter++;   /* exponential backoff warnings */
                 if ((counter & (-counter)) == counter)
                         CWARN("%u ENOMEM tx %p (%u allocated)\n",
-                              counter, conn, atomic_read(&libcfs_kmemory));
+                             counter, conn, atomic_read(&libcfs_kmemory));
 
                 /* Queue on ksnd_enomem_conns for retry after a timeout */
-                spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+               spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
 
                 /* enomem list takes over scheduler's ref... */
                 LASSERT (conn->ksnc_tx_scheduled);
-                list_add_tail(&conn->ksnc_tx_list,
-                              &ksocknal_data.ksnd_enomem_conns);
-                if (!cfs_time_aftereq(cfs_time_add(cfs_time_current(),
-                                                   SOCKNAL_ENOMEM_RETRY),
-                                   ksocknal_data.ksnd_reaper_waketime))
-                        cfs_waitq_signal (&ksocknal_data.ksnd_reaper_waitq);
-
-                spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
-                return (rc);
-        }
+               list_add_tail(&conn->ksnc_tx_list,
+                                  &ksocknal_data.ksnd_enomem_conns);
+               if (!cfs_time_aftereq(cfs_time_add(cfs_time_current(),
+                                       SOCKNAL_ENOMEM_RETRY),
+                                       ksocknal_data.ksnd_reaper_waketime))
+                       wake_up(&ksocknal_data.ksnd_reaper_waitq);
+
+               spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
+               return (rc);
+       }
 
         /* Actual error */
         LASSERT (rc < 0);
@@ -545,25 +555,24 @@ ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
         if (!conn->ksnc_closing) {
                 switch (rc) {
                 case -ECONNRESET:
-                        LCONSOLE_WARN("Host %u.%u.%u.%u reset our connection "
+                       LCONSOLE_WARN("Host %pI4h reset our connection "
                                       "while we were sending data; it may have "
                                       "rebooted.\n",
-                                      HIPQUAD(conn->ksnc_ipaddr));
+                                     &conn->ksnc_ipaddr);
                         break;
                 default:
                         LCONSOLE_WARN("There was an unexpected network error "
-                                      "while writing to %u.%u.%u.%u: %d.\n",
-                                      HIPQUAD(conn->ksnc_ipaddr), rc);
+                                     "while writing to %pI4h: %d.\n",
+                                     &conn->ksnc_ipaddr, rc);
                         break;
                 }
-                CDEBUG(D_NET, "[%p] Error %d on write to %s"
-                       " ip %d.%d.%d.%d:%d\n", conn, rc,
-                       libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                       HIPQUAD(conn->ksnc_ipaddr),
-                       conn->ksnc_port);
+               CDEBUG(D_NET, "[%p] Error %d on write to %s ip %pI4h:%d\n",
+                      conn, rc, libcfs_id2str(conn->ksnc_peer->ksnp_id),
+                      &conn->ksnc_ipaddr, conn->ksnc_port);
         }
 
-        ksocknal_unzc_req(tx);
+        if (tx->tx_zc_checked)
+                ksocknal_uncheck_zc_req(tx);
 
         /* it's not an error if conn is being closed */
         ksocknal_close_conn_and_siblings (conn,
@@ -572,7 +581,7 @@ ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
         return (rc);
 }
 
-void
+static void
 ksocknal_launch_connection_locked (ksock_route_t *route)
 {
 
@@ -585,134 +594,96 @@ ksocknal_launch_connection_locked (ksock_route_t *route)
         route->ksnr_scheduled = 1;              /* scheduling conn for connd */
         ksocknal_route_addref(route);           /* extra ref for connd */
 
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
+       spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
+
+       list_add_tail(&route->ksnr_connd_list,
+                         &ksocknal_data.ksnd_connd_routes);
+       wake_up(&ksocknal_data.ksnd_connd_waitq);
+
+       spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
+}
+
+void
+ksocknal_launch_all_connections_locked (ksock_peer_t *peer)
+{
+        ksock_route_t *route;
 
-        list_add_tail (&route->ksnr_connd_list,
-                       &ksocknal_data.ksnd_connd_routes);
-        cfs_waitq_signal (&ksocknal_data.ksnd_connd_waitq);
+        /* called holding write lock on ksnd_global_lock */
+        for (;;) {
+                /* launch any/all connections that need it */
+                route = ksocknal_find_connectable_route_locked(peer);
+                if (route == NULL)
+                        return;
 
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+                ksocknal_launch_connection_locked(route);
+        }
 }
 
 ksock_conn_t *
-ksocknal_find_conn_locked (int payload_nob, ksock_peer_t *peer)
+ksocknal_find_conn_locked(ksock_peer_t *peer, ksock_tx_t *tx, int nonblk)
 {
-        struct list_head *tmp;
+       struct list_head *tmp;
+        ksock_conn_t     *conn;
         ksock_conn_t     *typed = NULL;
-        int               tnob  = 0;
         ksock_conn_t     *fallback = NULL;
+        int               tnob     = 0;
         int               fnob     = 0;
-        ksock_conn_t     *conn;
-
-        list_for_each (tmp, &peer->ksnp_conns) {
-                ksock_conn_t *c = list_entry(tmp, ksock_conn_t, ksnc_list);
-                int           hdr_nob = 0;
-#if SOCKNAL_ROUND_ROBIN
-                const int     nob = 0;
-#else
-                int           nob = atomic_read(&c->ksnc_tx_nob) +
-                                        SOCK_WMEM_QUEUED(c->ksnc_sock);
-#endif
-                LASSERT (!c->ksnc_closing);
-                LASSERT (c->ksnc_proto != NULL);
 
-                if (fallback == NULL || nob < fnob) {
-                        fallback = c;
-                        fnob     = nob;
-                }
+       list_for_each(tmp, &peer->ksnp_conns) {
+               ksock_conn_t *c  = list_entry(tmp, ksock_conn_t, ksnc_list);
+               int           nob = atomic_read(&c->ksnc_tx_nob) +
+                                       c->ksnc_sock->sk->sk_wmem_queued;
+                int           rc;
 
-                if (!*ksocknal_tunables.ksnd_typed_conns)
-                        continue;
+                LASSERT (!c->ksnc_closing);
+                LASSERT (c->ksnc_proto != NULL &&
+                         c->ksnc_proto->pro_match_tx != NULL);
 
-                if (payload_nob == 0) {
-                        /* noop packet */
-                        hdr_nob = offsetof(ksock_msg_t, ksm_u);
-                } else {
-                        /* lnet packet */
-                        hdr_nob = (c->ksnc_proto == &ksocknal_protocol_v2x)?
-                                  offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload):
-                                  sizeof(lnet_hdr_t);
-                }
+                rc = c->ksnc_proto->pro_match_tx(c, tx, nonblk);
 
-                switch (c->ksnc_type) {
+                switch (rc) {
                 default:
-                        CERROR("ksnc_type bad: %u\n", c->ksnc_type);
                         LBUG();
-                case SOCKLND_CONN_ANY:
-                        break;
-                case SOCKLND_CONN_BULK_IN:
+                case SOCKNAL_MATCH_NO: /* protocol rejected the tx */
                         continue;
-                case SOCKLND_CONN_BULK_OUT:
-                        if ((hdr_nob + payload_nob) < *ksocknal_tunables.ksnd_min_bulk)
-                                continue;
-                        break;
-                case SOCKLND_CONN_CONTROL:
-                        if ((hdr_nob + payload_nob) >= *ksocknal_tunables.ksnd_min_bulk)
-                                continue;
+
+                case SOCKNAL_MATCH_YES: /* typed connection */
+                        if (typed == NULL || tnob > nob ||
+                            (tnob == nob && *ksocknal_tunables.ksnd_round_robin &&
+                             cfs_time_after(typed->ksnc_tx_last_post, c->ksnc_tx_last_post))) {
+                                typed = c;
+                                tnob  = nob;
+                        }
                         break;
-                }
 
-                if (typed == NULL || nob < tnob) {
-                        typed = c;
-                        tnob  = nob;
+                case SOCKNAL_MATCH_MAY: /* fallback connection */
+                        if (fallback == NULL || fnob > nob ||
+                            (fnob == nob && *ksocknal_tunables.ksnd_round_robin &&
+                             cfs_time_after(fallback->ksnc_tx_last_post, c->ksnc_tx_last_post))) {
+                                fallback = c;
+                                fnob     = nob;
+                        }
+                        break;
                 }
         }
 
         /* prefer the typed selection */
         conn = (typed != NULL) ? typed : fallback;
 
-#if SOCKNAL_ROUND_ROBIN
-        if (conn != NULL) {
-                /* round-robin all else being equal */
-                list_del (&conn->ksnc_list);
-                list_add_tail (&conn->ksnc_list, &peer->ksnp_conns);
-        }
-#endif
+        if (conn != NULL)
+                conn->ksnc_tx_last_post = cfs_time_current();
+
         return conn;
 }
 
 void
-ksocknal_next_mono_tx(ksock_conn_t *conn)
-{
-        ksock_tx_t     *tx = conn->ksnc_tx_mono;
-
-        /* Called holding BH lock: conn->ksnc_scheduler->kss_lock */
-        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
-        LASSERT(!list_empty(&conn->ksnc_tx_queue));
-        LASSERT(tx != NULL);
-
-        if (tx->tx_list.next == &conn->ksnc_tx_queue) {
-                /* no more packets queued */
-                conn->ksnc_tx_mono = NULL;
-        } else {
-                conn->ksnc_tx_mono = list_entry(tx->tx_list.next, ksock_tx_t, tx_list);
-                LASSERT(conn->ksnc_tx_mono->tx_msg.ksm_type == tx->tx_msg.ksm_type);
-        }
-}
-
-int
-ksocknal_piggyback_zcack(ksock_conn_t *conn, __u64 cookie)
+ksocknal_tx_prep(ksock_conn_t *conn, ksock_tx_t *tx)
 {
-        ksock_tx_t     *tx = conn->ksnc_tx_mono;
-
-        /* Called holding BH lock: conn->ksnc_scheduler->kss_lock */
-
-        if (tx == NULL)
-                return 0;
-
-        if (tx->tx_msg.ksm_type == KSOCK_MSG_NOOP) {
-                /* tx is noop zc-ack, can't piggyback zc-ack cookie */
-                return 0;
-        }
-
-        LASSERT(tx->tx_msg.ksm_type == KSOCK_MSG_LNET);
-        LASSERT(tx->tx_msg.ksm_zc_ack_cookie == 0);
-
-        /* piggyback the zc-ack cookie */
-        tx->tx_msg.ksm_zc_ack_cookie = cookie;
-        ksocknal_next_mono_tx(conn);
+        conn->ksnc_proto->pro_pack(tx);
 
-        return 1;
+       atomic_add (tx->tx_nob, &conn->ksnc_tx_nob);
+        ksocknal_conn_addref(conn); /* +1 ref for tx */
+        tx->tx_conn = conn;
 }
 
 void
@@ -720,7 +691,7 @@ ksocknal_queue_tx_locked (ksock_tx_t *tx, ksock_conn_t *conn)
 {
         ksock_sched_t *sched = conn->ksnc_scheduler;
         ksock_msg_t   *msg = &tx->tx_msg;
-        ksock_tx_t    *ztx;
+        ksock_tx_t    *ztx = NULL;
         int            bufnob = 0;
 
         /* called holding global lock (read or irq-write) and caller may
@@ -729,133 +700,89 @@ ksocknal_queue_tx_locked (ksock_tx_t *tx, ksock_conn_t *conn)
          * ksnc_sock... */
         LASSERT(!conn->ksnc_closing);
 
-        CDEBUG (D_NET, "Sending to %s ip %d.%d.%d.%d:%d\n",
-                libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                HIPQUAD(conn->ksnc_ipaddr),
-                conn->ksnc_port);
+       CDEBUG(D_NET, "Sending to %s ip %pI4h:%d\n",
+              libcfs_id2str(conn->ksnc_peer->ksnp_id),
+              &conn->ksnc_ipaddr, conn->ksnc_port);
 
-        tx->tx_checked_zc = 0;
-        conn->ksnc_proto->pro_pack(tx);
+        ksocknal_tx_prep(conn, tx);
 
         /* Ensure the frags we've been given EXACTLY match the number of
          * bytes we want to send.  Many TCP/IP stacks disregard any total
-         * size parameters passed to them and just look at the frags. 
+        * size parameters passed to them and just look at the frags.
          *
          * We always expect at least 1 mapped fragment containing the
          * complete ksocknal message header. */
         LASSERT (lnet_iov_nob (tx->tx_niov, tx->tx_iov) +
-                 lnet_kiov_nob (tx->tx_nkiov, tx->tx_kiov) == tx->tx_nob);
+                 lnet_kiov_nob(tx->tx_nkiov, tx->tx_kiov) ==
+                 (unsigned int)tx->tx_nob);
         LASSERT (tx->tx_niov >= 1);
         LASSERT (tx->tx_resid == tx->tx_nob);
 
         CDEBUG (D_NET, "Packet %p type %d, nob %d niov %d nkiov %d\n",
-                tx, (tx->tx_lnetmsg != NULL)? tx->tx_lnetmsg->msg_hdr.type:
-                                              KSOCK_MSG_NOOP,
+                tx, (tx->tx_lnetmsg != NULL) ? tx->tx_lnetmsg->msg_hdr.type:
+                                               KSOCK_MSG_NOOP,
                 tx->tx_nob, tx->tx_niov, tx->tx_nkiov);
 
-        atomic_add (tx->tx_nob, &conn->ksnc_tx_nob);
-        tx->tx_conn = conn;
-        ksocknal_conn_addref(conn); /* +1 ref for tx */
-
-        /* 
-         * NB Darwin: SOCK_WMEM_QUEUED()->sock_getsockopt() will take
-         * a blockable lock(socket lock), so SOCK_WMEM_QUEUED can't be
-         * put in spinlock. 
-         */
-        bufnob = SOCK_WMEM_QUEUED(conn->ksnc_sock);
-        spin_lock_bh (&sched->kss_lock);
-
-        if (list_empty(&conn->ksnc_tx_queue) && bufnob == 0) {
-                /* First packet starts the timeout */
-                conn->ksnc_tx_deadline =
-                        cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-                conn->ksnc_tx_bufnob = 0;
-                mb();    /* order with adding to tx_queue */
-        }
+       bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
+       spin_lock_bh(&sched->kss_lock);
 
-        ztx = NULL;
+       if (list_empty(&conn->ksnc_tx_queue) && bufnob == 0) {
+               /* First packet starts the timeout */
+               conn->ksnc_tx_deadline =
+                       cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+               if (conn->ksnc_tx_bufnob > 0) /* something got ACKed */
+                       conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
+               conn->ksnc_tx_bufnob = 0;
+               smp_mb(); /* order with adding to tx_queue */
+       }
 
-        if (msg->ksm_type == KSOCK_MSG_NOOP) {
-                /* The packet is noop ZC ACK, try to piggyback the ack_cookie
-                 * on a normal packet so I don't need to send it */
-                LASSERT(msg->ksm_zc_req_cookie == 0);
-                LASSERT(msg->ksm_zc_ack_cookie != 0);
+       if (msg->ksm_type == KSOCK_MSG_NOOP) {
+               /* The packet is noop ZC ACK, try to piggyback the ack_cookie
+                * on a normal packet so I don't need to send it */
+                LASSERT (msg->ksm_zc_cookies[1] != 0);
+                LASSERT (conn->ksnc_proto->pro_queue_tx_zcack != NULL);
 
-                if (conn->ksnc_tx_mono != NULL) {
-                        if (ksocknal_piggyback_zcack(conn, msg->ksm_zc_ack_cookie)) {
-                                /* zc-ack cookie is piggybacked */
-                                atomic_sub (tx->tx_nob, &conn->ksnc_tx_nob);
-                                ztx = tx;       /* Put to freelist later */
-                        } else {
-                                /* no packet can piggyback zc-ack cookie */
-                                list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                        }
-                } else {
-                        /* It's the first mono-packet */
-                        conn->ksnc_tx_mono = tx;
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                }
+                if (conn->ksnc_proto->pro_queue_tx_zcack(conn, tx, 0))
+                        ztx = tx; /* ZC ACK piggybacked on ztx release tx later */
 
         } else {
                 /* It's a normal packet - can it piggback a noop zc-ack that
                  * has been queued already? */
-                LASSERT(msg->ksm_zc_ack_cookie == 0);
+                LASSERT (msg->ksm_zc_cookies[1] == 0);
+                LASSERT (conn->ksnc_proto->pro_queue_tx_msg != NULL);
 
-                if (conn->ksnc_proto == &ksocknal_protocol_v2x &&  /* V2.x packet */
-                    conn->ksnc_tx_mono != NULL) {
-                        if (conn->ksnc_tx_mono->tx_msg.ksm_type == KSOCK_MSG_NOOP) {
-                                /* There is a noop zc-ack can be piggybacked */
-                                ztx = conn->ksnc_tx_mono;
-
-                                msg->ksm_zc_ack_cookie = ztx->tx_msg.ksm_zc_ack_cookie;
-                                ksocknal_next_mono_tx(conn);
-
-                                /* use tx to replace the noop zc-ack packet, ztx will
-                                 * be put to freelist later */
-                                list_add(&tx->tx_list, &ztx->tx_list);
-                                list_del(&ztx->tx_list);
-
-                                atomic_sub (ztx->tx_nob, &conn->ksnc_tx_nob);
-                        } else {
-                                /* no noop zc-ack packet, just enqueue it */
-                                LASSERT(conn->ksnc_tx_mono->tx_msg.ksm_type == KSOCK_MSG_LNET);
-                                list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                        }
-
-                } else if (conn->ksnc_proto == &ksocknal_protocol_v2x) {
-                        /* it's the first mono-packet, enqueue it */
-                        conn->ksnc_tx_mono = tx;
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                } else {
-                        /* V1.x packet, just enqueue it */
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                }
+                ztx = conn->ksnc_proto->pro_queue_tx_msg(conn, tx);
+                /* ztx will be released later */
         }
 
-        if (ztx != NULL)
-                list_add_tail(&ztx->tx_list, &sched->kss_zombie_noop_txs);
-
-        if (conn->ksnc_tx_ready &&      /* able to send */
-            !conn->ksnc_tx_scheduled) { /* not scheduled to send */
-                /* +1 ref for scheduler */
-                ksocknal_conn_addref(conn);
-                list_add_tail (&conn->ksnc_tx_list,
-                               &sched->kss_tx_conns);
-                conn->ksnc_tx_scheduled = 1;
-                cfs_waitq_signal (&sched->kss_waitq);
+        if (ztx != NULL) {
+               atomic_sub (ztx->tx_nob, &conn->ksnc_tx_nob);
+               list_add_tail(&ztx->tx_list, &sched->kss_zombie_noop_txs);
         }
 
-        spin_unlock_bh (&sched->kss_lock);
+       if (conn->ksnc_tx_ready &&      /* able to send */
+           !conn->ksnc_tx_scheduled) { /* not scheduled to send */
+               /* +1 ref for scheduler */
+               ksocknal_conn_addref(conn);
+               list_add_tail(&conn->ksnc_tx_list,
+                                  &sched->kss_tx_conns);
+               conn->ksnc_tx_scheduled = 1;
+               wake_up(&sched->kss_waitq);
+       }
+
+       spin_unlock_bh(&sched->kss_lock);
 }
 
+
 ksock_route_t *
 ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
 {
-        struct list_head  *tmp;
-        ksock_route_t     *route;
+        cfs_time_t     now = cfs_time_current();
+       struct list_head    *tmp;
+        ksock_route_t *route;
 
-        list_for_each (tmp, &peer->ksnp_routes) {
-                route = list_entry (tmp, ksock_route_t, ksnr_list);
+       list_for_each(tmp, &peer->ksnp_routes) {
+               route = list_entry(tmp, ksock_route_t, ksnr_list);
 
                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
 
@@ -866,11 +793,17 @@ ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
                 if ((ksocknal_route_mask() & ~route->ksnr_connected) == 0)
                         continue;
 
-                /* too soon to retry this guy? */
                 if (!(route->ksnr_retry_interval == 0 || /* first attempt */
-                      cfs_time_aftereq (cfs_time_current(),
-                                        route->ksnr_timeout)))
+                      cfs_time_aftereq(now, route->ksnr_timeout))) {
+                        CDEBUG(D_NET,
+                              "Too soon to retry route %pI4h "
+                               "(cnted %d, interval %ld, %ld secs later)\n",
+                              &route->ksnr_ipaddr,
+                               route->ksnr_connected,
+                               route->ksnr_retry_interval,
+                               cfs_duration_sec(route->ksnr_timeout - now));
                         continue;
+                }
 
                 return (route);
         }
@@ -881,11 +814,11 @@ ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
 ksock_route_t *
 ksocknal_find_connecting_route_locked (ksock_peer_t *peer)
 {
-        struct list_head  *tmp;
+       struct list_head        *tmp;
         ksock_route_t     *route;
 
-        list_for_each (tmp, &peer->ksnp_routes) {
-                route = list_entry (tmp, ksock_route_t, ksnr_list);
+       list_for_each(tmp, &peer->ksnp_routes) {
+               route = list_entry(tmp, ksock_route_t, ksnr_list);
 
                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
 
@@ -901,44 +834,41 @@ ksocknal_launch_packet (lnet_ni_t *ni, ksock_tx_t *tx, lnet_process_id_t id)
 {
         ksock_peer_t     *peer;
         ksock_conn_t     *conn;
-        ksock_route_t    *route;
-        rwlock_t         *g_lock;
+       rwlock_t     *g_lock;
         int               retry;
         int               rc;
 
         LASSERT (tx->tx_conn == NULL);
-        LASSERT (tx->tx_lnetmsg != NULL);
 
         g_lock = &ksocknal_data.ksnd_global_lock;
 
         for (retry = 0;; retry = 1) {
-#if !SOCKNAL_ROUND_ROBIN
-                read_lock (g_lock);
+               read_lock(g_lock);
                 peer = ksocknal_find_peer_locked(ni, id);
                 if (peer != NULL) {
                         if (ksocknal_find_connectable_route_locked(peer) == NULL) {
-                                conn = ksocknal_find_conn_locked (tx->tx_lnetmsg->msg_len, peer);
+                                conn = ksocknal_find_conn_locked(peer, tx, tx->tx_nonblk);
                                 if (conn != NULL) {
                                         /* I've got no routes that need to be
                                          * connecting and I do have an actual
                                          * connection... */
                                         ksocknal_queue_tx_locked (tx, conn);
-                                        read_unlock (g_lock);
+                                       read_unlock(g_lock);
                                         return (0);
                                 }
                         }
                 }
 
                 /* I'll need a write lock... */
-                read_unlock (g_lock);
-#endif
-                write_lock_bh (g_lock);
+               read_unlock(g_lock);
+
+               write_lock_bh(g_lock);
 
                 peer = ksocknal_find_peer_locked(ni, id);
                 if (peer != NULL)
                         break;
 
-                write_unlock_bh (g_lock);
+               write_unlock_bh(g_lock);
 
                 if ((id.pid & LNET_PID_USERFLAG) != 0) {
                         CERROR("Refusing to create a connection to "
@@ -961,41 +891,39 @@ ksocknal_launch_packet (lnet_ni_t *ni, ksock_tx_t *tx, lnet_process_id_t id)
                 }
         }
 
-        for (;;) {
-                /* launch any/all connections that need it */
-                route = ksocknal_find_connectable_route_locked (peer);
-                if (route == NULL)
-                        break;
-
-                ksocknal_launch_connection_locked (route);
-        }
+        ksocknal_launch_all_connections_locked(peer);
 
-        conn = ksocknal_find_conn_locked (tx->tx_lnetmsg->msg_len, peer);
+        conn = ksocknal_find_conn_locked(peer, tx, tx->tx_nonblk);
         if (conn != NULL) {
                 /* Connection exists; queue message on it */
                 ksocknal_queue_tx_locked (tx, conn);
-                write_unlock_bh (g_lock);
+               write_unlock_bh(g_lock);
                 return (0);
         }
 
         if (peer->ksnp_accepting > 0 ||
             ksocknal_find_connecting_route_locked (peer) != NULL) {
+                /* the message is going to be pinned to the peer */
+                tx->tx_deadline =
+                        cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
+
                 /* Queue the message until a connection is established */
-                list_add_tail (&tx->tx_list, &peer->ksnp_tx_queue);
-                write_unlock_bh (g_lock);
+               list_add_tail(&tx->tx_list, &peer->ksnp_tx_queue);
+               write_unlock_bh(g_lock);
                 return 0;
         }
 
-        write_unlock_bh (g_lock);
+       write_unlock_bh(g_lock);
 
         /* NB Routes may be ignored if connections to them failed recently */
-        CDEBUG(D_NETERROR, "No usable routes to %s\n", libcfs_id2str(id));
+        CNETERR("No usable routes to %s\n", libcfs_id2str(id));
         return (-EHOSTUNREACH);
 }
 
 int
 ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 {
+        int               mpflag = 1;
         int               type = lntmsg->msg_type;
         lnet_process_id_t target = lntmsg->msg_target;
         unsigned int      payload_niov = lntmsg->msg_niov;
@@ -1013,23 +941,27 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
         CDEBUG(D_NET, "sending %u bytes in %d frags to %s\n",
                payload_nob, payload_niov, libcfs_id2str(target));
 
-        LASSERT (payload_nob == 0 || payload_niov > 0);
-        LASSERT (payload_niov <= LNET_MAX_IOV);
-        /* payload is either all vaddrs or all pages */
-        LASSERT (!(payload_kiov != NULL && payload_iov != NULL));
-        LASSERT (!in_interrupt ());
-
-        if (payload_iov != NULL)
-                desc_size = offsetof(ksock_tx_t,
-                                     tx_frags.virt.iov[1 + payload_niov]);
-        else
-                desc_size = offsetof(ksock_tx_t,
-                                     tx_frags.paged.kiov[payload_niov]);
-
-        tx = ksocknal_alloc_tx(desc_size);
+       LASSERT (payload_nob == 0 || payload_niov > 0);
+       LASSERT (payload_niov <= LNET_MAX_IOV);
+       /* payload is either all vaddrs or all pages */
+       LASSERT (!(payload_kiov != NULL && payload_iov != NULL));
+       LASSERT (!in_interrupt ());
+
+       if (payload_iov != NULL)
+               desc_size = offsetof(ksock_tx_t,
+                                    tx_frags.virt.iov[1 + payload_niov]);
+       else
+               desc_size = offsetof(ksock_tx_t,
+                                    tx_frags.paged.kiov[payload_niov]);
+
+        if (lntmsg->msg_vmflush)
+                mpflag = cfs_memory_pressure_get_and_set();
+        tx = ksocknal_alloc_tx(KSOCK_MSG_LNET, desc_size);
         if (tx == NULL) {
                 CERROR("Can't allocate tx desc type %d size %d\n",
                        type, desc_size);
+                if (lntmsg->msg_vmflush)
+                        cfs_memory_pressure_restore(mpflag);
                 return (-ENOMEM);
         }
 
@@ -1051,12 +983,18 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
                 tx->tx_nkiov = lnet_extract_kiov(payload_niov, tx->tx_kiov,
                                                  payload_niov, payload_kiov,
                                                  payload_offset, payload_nob);
+
+                if (payload_nob >= *ksocknal_tunables.ksnd_zc_min_payload)
+                        tx->tx_zc_capable = 1;
         }
 
-        ksocknal_init_msg(&tx->tx_msg, KSOCK_MSG_LNET);
+        socklnd_init_msg(&tx->tx_msg, KSOCK_MSG_LNET);
 
         /* The first fragment will be set later in pro_pack */
         rc = ksocknal_launch_packet(ni, tx, target);
+        if (!mpflag)
+                cfs_memory_pressure_restore(mpflag);
+
         if (rc == 0)
                 return (0);
 
@@ -1065,25 +1003,25 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 }
 
 int
-ksocknal_thread_start (int (*fn)(void *arg), void *arg)
+ksocknal_thread_start(int (*fn)(void *arg), void *arg, char *name)
 {
-        long          pid = cfs_kernel_thread (fn, arg, 0);
+       struct task_struct *task = kthread_run(fn, arg, name);
 
-        if (pid < 0)
-                return ((int)pid);
+       if (IS_ERR(task))
+               return PTR_ERR(task);
 
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
-        ksocknal_data.ksnd_nthreads++;
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
-        return (0);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
+       ksocknal_data.ksnd_nthreads++;
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+       return 0;
 }
 
 void
 ksocknal_thread_fini (void)
 {
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
         ksocknal_data.ksnd_nthreads--;
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
 }
 
 int
@@ -1102,12 +1040,13 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
                 ksocknal_lib_eager_ack(conn);
         }
 
-        if (nob_to_skip == 0) {         /* right at next packet boundary now */
-                conn->ksnc_rx_started = 0;
-                mb ();                          /* racing with timeout thread */
+       if (nob_to_skip == 0) {         /* right at next packet boundary now */
+               conn->ksnc_rx_started = 0;
+               smp_mb();                       /* racing with timeout thread */
 
-                switch (conn->ksnc_proto->pro_version) {
-                case  KSOCK_PROTO_V2:
+               switch (conn->ksnc_proto->pro_version) {
+               case  KSOCK_PROTO_V2:
+               case  KSOCK_PROTO_V3:
                         conn->ksnc_rx_state = SOCKNAL_RX_KSM_HEADER;
                         conn->ksnc_rx_iov = (struct iovec *)&conn->ksnc_rx_iov_space;
                         conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg;
@@ -1167,101 +1106,14 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
         return (0);
 }
 
-/* (Sink) handle incoming ZC request from sender */
-static int
-ksocknal_handle_zc_req(ksock_peer_t *peer, __u64 cookie)
-{
-        ksock_conn_t   *conn;
-        ksock_tx_t     *tx;
-        ksock_sched_t  *sched;
-        int             rc;
-
-        read_lock (&ksocknal_data.ksnd_global_lock);
-
-        conn = ksocknal_find_conn_locked (0, peer);
-        if (conn == NULL) {
-                read_unlock (&ksocknal_data.ksnd_global_lock);
-                CERROR("Can't find connection to send zcack.\n");
-                return -ECONNRESET;
-        }
-
-        sched = conn->ksnc_scheduler;
-
-        spin_lock_bh (&sched->kss_lock);
-        rc = ksocknal_piggyback_zcack(conn, cookie);
-        spin_unlock_bh (&sched->kss_lock);
-
-        read_unlock (&ksocknal_data.ksnd_global_lock);
-        if (rc) {
-                /* Ack cookie is piggybacked */
-                return 0;
-        }
-
-        tx = ksocknal_alloc_tx(KSOCK_NOOP_TX_SIZE);
-        if (tx == NULL) {
-                CERROR("Can't allocate noop tx desc\n");
-                return -ENOMEM;
-        }
-
-        tx->tx_conn     = NULL;
-        tx->tx_lnetmsg  = NULL;
-        tx->tx_kiov     = NULL;
-        tx->tx_nkiov    = 0;
-        tx->tx_iov      = tx->tx_frags.virt.iov;
-        tx->tx_niov     = 1;
-
-        ksocknal_init_msg(&tx->tx_msg, KSOCK_MSG_NOOP);
-        tx->tx_msg.ksm_zc_ack_cookie = cookie; /* incoming cookie */
-
-        read_lock (&ksocknal_data.ksnd_global_lock);
-
-        conn = ksocknal_find_conn_locked (0, peer);
-        if (conn == NULL) {
-                read_unlock (&ksocknal_data.ksnd_global_lock);
-                ksocknal_free_tx(tx);
-                CERROR("Can't find connection to send zcack.\n");
-                return -ECONNRESET;
-        }
-        ksocknal_queue_tx_locked(tx, conn);
-
-        read_unlock (&ksocknal_data.ksnd_global_lock);
-
-        return 0;
-}
-
-/* (Sender) handle ZC_ACK from sink */
 static int
-ksocknal_handle_zc_ack(ksock_peer_t *peer, __u64 cookie)
-{
-        ksock_tx_t             *tx;
-        struct list_head       *ctmp;
-
-        spin_lock(&peer->ksnp_lock);
-
-        list_for_each(ctmp, &peer->ksnp_zc_req_list) {
-                tx = list_entry (ctmp, ksock_tx_t, tx_zc_list);
-                if (tx->tx_msg.ksm_zc_req_cookie != cookie)
-                        continue;
-
-                tx->tx_msg.ksm_zc_req_cookie = 0;
-                list_del(&tx->tx_zc_list);
-
-                spin_unlock(&peer->ksnp_lock);
-
-                ksocknal_tx_decref(tx);
-                return 0;
-        }
-        spin_unlock(&peer->ksnp_lock);
-
-        return -EPROTO;
-}
-
-int
 ksocknal_process_receive (ksock_conn_t *conn)
 {
-        int           rc;
+        lnet_hdr_t        *lhdr;
+        lnet_process_id_t *id;
+        int                rc;
 
-        LASSERT (atomic_read(&conn->ksnc_conn_refcount) > 0);
+       LASSERT (atomic_read(&conn->ksnc_conn_refcount) > 0);
 
         /* NB: sched lock NOT held */
         /* SOCKNAL_RX_LNET_HEADER is here for backward compatability */
@@ -1273,22 +1125,23 @@ ksocknal_process_receive (ksock_conn_t *conn)
         if (conn->ksnc_rx_nob_wanted != 0) {
                 rc = ksocknal_receive(conn);
 
-                if (rc <= 0) {
-                        LASSERT (rc != -EAGAIN);
+               if (rc <= 0) {
+                       lnet_process_id_t ksnp_id = conn->ksnc_peer->ksnp_id;
 
-                        if (rc == 0)
-                                CDEBUG (D_NET, "[%p] EOF from %s"
-                                        " ip %d.%d.%d.%d:%d\n", conn,
-                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                        HIPQUAD(conn->ksnc_ipaddr),
-                                        conn->ksnc_port);
-                        else if (!conn->ksnc_closing)
-                                CERROR ("[%p] Error %d on read from %s"
-                                        " ip %d.%d.%d.%d:%d\n",
-                                        conn, rc,
-                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                        HIPQUAD(conn->ksnc_ipaddr),
+                       LASSERT(rc != -EAGAIN);
+
+                       if (rc == 0)
+                               CDEBUG(D_NET, "[%p] EOF from %s "
+                                      "ip %pI4h:%d\n", conn,
+                                       libcfs_id2str(ksnp_id),
+                                       &conn->ksnc_ipaddr,
                                         conn->ksnc_port);
+                       else if (!conn->ksnc_closing)
+                               CERROR("[%p] Error %d on read from %s "
+                                      "ip %pI4h:%d\n", conn, rc,
+                                      libcfs_id2str(ksnp_id),
+                                      &conn->ksnc_ipaddr,
+                                      conn->ksnc_port);
 
                         /* it's not an error if conn is being closed */
                         ksocknal_close_conn_and_siblings (conn,
@@ -1306,8 +1159,18 @@ ksocknal_process_receive (ksock_conn_t *conn)
                 if (conn->ksnc_flip) {
                         __swab32s(&conn->ksnc_msg.ksm_type);
                         __swab32s(&conn->ksnc_msg.ksm_csum);
-                        __swab64s(&conn->ksnc_msg.ksm_zc_req_cookie);
-                        __swab64s(&conn->ksnc_msg.ksm_zc_ack_cookie);
+                        __swab64s(&conn->ksnc_msg.ksm_zc_cookies[0]);
+                        __swab64s(&conn->ksnc_msg.ksm_zc_cookies[1]);
+                }
+
+                if (conn->ksnc_msg.ksm_type != KSOCK_MSG_NOOP &&
+                    conn->ksnc_msg.ksm_type != KSOCK_MSG_LNET) {
+                        CERROR("%s: Unknown message type: %x\n",
+                               libcfs_id2str(conn->ksnc_peer->ksnp_id),
+                               conn->ksnc_msg.ksm_type);
+                        ksocknal_new_packet(conn, 0);
+                        ksocknal_close_conn_and_siblings(conn, -EPROTO);
+                        return (-EPROTO);
                 }
 
                 if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP &&
@@ -1322,15 +1185,21 @@ ksocknal_process_receive (ksock_conn_t *conn)
                         return (-EIO);
                 }
 
-                if (conn->ksnc_msg.ksm_zc_ack_cookie != 0) {
-                        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
+                if (conn->ksnc_msg.ksm_zc_cookies[1] != 0) {
+                        __u64 cookie = 0;
+
+                        LASSERT (conn->ksnc_proto != &ksocknal_protocol_v1x);
+
+                        if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP)
+                                cookie = conn->ksnc_msg.ksm_zc_cookies[0];
+
+                        rc = conn->ksnc_proto->pro_handle_zcack(conn, cookie,
+                                               conn->ksnc_msg.ksm_zc_cookies[1]);
 
-                        rc = ksocknal_handle_zc_ack(conn->ksnc_peer,
-                                                    conn->ksnc_msg.ksm_zc_ack_cookie);
                         if (rc != 0) {
-                                CERROR("%s: Unknown zero copy ACK cookie: "LPU64"\n",
+                                CERROR("%s: Unknown ZC-ACK cookie: "LPU64", "LPU64"\n",
                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                       conn->ksnc_msg.ksm_zc_ack_cookie);
+                                       cookie, conn->ksnc_msg.ksm_zc_cookies[1]);
                                 ksocknal_new_packet(conn, 0);
                                 ksocknal_close_conn_and_siblings(conn, -EPROTO);
                                 return (rc);
@@ -1341,7 +1210,6 @@ ksocknal_process_receive (ksock_conn_t *conn)
                         ksocknal_new_packet (conn, 0);
                         return 0;       /* NOOP is done and just return */
                 }
-                LASSERT (conn->ksnc_msg.ksm_type == KSOCK_MSG_LNET);
 
                 conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
                 conn->ksnc_rx_nob_wanted = sizeof(ksock_lnet_msg_t);
@@ -1363,8 +1231,8 @@ ksocknal_process_receive (ksock_conn_t *conn)
 
                 if ((conn->ksnc_peer->ksnp_id.pid & LNET_PID_USERFLAG) != 0) {
                         /* Userspace peer */
-                        lnet_process_id_t *id = &conn->ksnc_peer->ksnp_id;
-                        lnet_hdr_t        *lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
+                        lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
+                        id   = &conn->ksnc_peer->ksnp_id;
 
                         /* Substitute process ID assigned at connection time */
                         lhdr->src_pid = cpu_to_le32(id->pid);
@@ -1408,14 +1276,20 @@ ksocknal_process_receive (ksock_conn_t *conn)
                         rc = -EIO;
                 }
 
-                lnet_finalize(conn->ksnc_peer->ksnp_ni, conn->ksnc_cookie, rc);
+                if (rc == 0 && conn->ksnc_msg.ksm_zc_cookies[0] != 0) {
+                        LASSERT(conn->ksnc_proto != &ksocknal_protocol_v1x);
+
+                        lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
+                        id   = &conn->ksnc_peer->ksnp_id;
 
-                if (rc == 0 && conn->ksnc_msg.ksm_zc_req_cookie != 0) {
-                        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
-                        rc = ksocknal_handle_zc_req(conn->ksnc_peer,
-                                                    conn->ksnc_msg.ksm_zc_req_cookie);
+                        rc = conn->ksnc_proto->pro_handle_zcreq(conn,
+                                        conn->ksnc_msg.ksm_zc_cookies[0],
+                                        *ksocknal_tunables.ksnd_nonblk_zcack ||
+                                        le64_to_cpu(lhdr->src_nid) != id->nid);
                 }
 
+                lnet_finalize(conn->ksnc_peer->ksnp_ni, conn->ksnc_cookie, rc);
+
                 if (rc != 0) {
                         ksocknal_new_packet(conn, 0);
                         ksocknal_close_conn_and_siblings (conn, rc);
@@ -1475,14 +1349,14 @@ ksocknal_recv (lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
 
         LASSERT (conn->ksnc_rx_scheduled);
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
 
-        switch (conn->ksnc_rx_state) {
-        case SOCKNAL_RX_PARSE_WAIT:
-                list_add_tail(&conn->ksnc_rx_list, &sched->kss_rx_conns);
-                cfs_waitq_signal (&sched->kss_waitq);
-                LASSERT (conn->ksnc_rx_ready);
-                break;
+       switch (conn->ksnc_rx_state) {
+       case SOCKNAL_RX_PARSE_WAIT:
+               list_add_tail(&conn->ksnc_rx_list, &sched->kss_rx_conns);
+               wake_up(&sched->kss_waitq);
+               LASSERT(conn->ksnc_rx_ready);
+               break;
 
         case SOCKNAL_RX_PARSE:
                 /* scheduler hasn't noticed I'm parsing yet */
@@ -1491,62 +1365,58 @@ ksocknal_recv (lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
 
         conn->ksnc_rx_state = SOCKNAL_RX_LNET_PAYLOAD;
 
-        spin_unlock_bh (&sched->kss_lock);
-        ksocknal_conn_decref(conn);
-        return (0);
+       spin_unlock_bh(&sched->kss_lock);
+       ksocknal_conn_decref(conn);
+       return 0;
 }
 
 static inline int
 ksocknal_sched_cansleep(ksock_sched_t *sched)
 {
-        int           rc;
+       int           rc;
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
 
-        rc = (!ksocknal_data.ksnd_shuttingdown &&
-              list_empty(&sched->kss_rx_conns) &&
-              list_empty(&sched->kss_tx_conns));
+       rc = (!ksocknal_data.ksnd_shuttingdown &&
+             list_empty(&sched->kss_rx_conns) &&
+             list_empty(&sched->kss_tx_conns));
 
-        spin_unlock_bh (&sched->kss_lock);
-        return (rc);
+       spin_unlock_bh(&sched->kss_lock);
+       return rc;
 }
 
-int ksocknal_scheduler (void *arg)
+int ksocknal_scheduler(void *arg)
 {
-        ksock_sched_t     *sched = (ksock_sched_t *)arg;
-        ksock_conn_t      *conn;
-        ksock_tx_t        *tx;
-        int                rc;
-        int                nloops = 0;
-        int                id = sched - ksocknal_data.ksnd_schedulers;
-        char               name[16];
+       struct ksock_sched_info *info;
+       ksock_sched_t           *sched;
+       ksock_conn_t            *conn;
+       ksock_tx_t              *tx;
+       int                     rc;
+       int                     nloops = 0;
+       long                    id = (long)arg;
 
-        snprintf (name, sizeof (name),"socknal_sd%02d", id);
-        cfs_daemonize (name);
-        cfs_block_allsigs ();
+       info = ksocknal_data.ksnd_sched_info[KSOCK_THREAD_CPT(id)];
+       sched = &info->ksi_scheds[KSOCK_THREAD_SID(id)];
 
-#if defined(CONFIG_SMP) && defined(CPU_AFFINITY)
-        id = ksocknal_sched2cpu(id);
-        if (cpu_online(id)) {
-                cpumask_t m = CPU_MASK_NONE;
-                cpu_set(id, m);
-                set_cpus_allowed(current, m);
-        } else {
-                CERROR ("Can't set CPU affinity for %s to %d\n", name, id);
-        }
-#endif /* CONFIG_SMP && CPU_AFFINITY */
+       cfs_block_allsigs();
 
-        spin_lock_bh (&sched->kss_lock);
+       rc = cfs_cpt_bind(lnet_cpt_table(), info->ksi_cpt);
+       if (rc != 0) {
+               CERROR("Can't set CPT affinity to %d: %d\n",
+                      info->ksi_cpt, rc);
+       }
+
+       spin_lock_bh(&sched->kss_lock);
 
         while (!ksocknal_data.ksnd_shuttingdown) {
                 int did_something = 0;
 
                 /* Ensure I progress everything semi-fairly */
 
-                if (!list_empty (&sched->kss_rx_conns)) {
-                        conn = list_entry(sched->kss_rx_conns.next,
-                                          ksock_conn_t, ksnc_rx_list);
-                        list_del(&conn->ksnc_rx_list);
+               if (!list_empty(&sched->kss_rx_conns)) {
+                       conn = list_entry(sched->kss_rx_conns.next,
+                                              ksock_conn_t, ksnc_rx_list);
+                       list_del(&conn->ksnc_rx_list);
 
                         LASSERT(conn->ksnc_rx_scheduled);
                         LASSERT(conn->ksnc_rx_ready);
@@ -1556,11 +1426,11 @@ int ksocknal_scheduler (void *arg)
                          * data_ready can set it any time after we release
                          * kss_lock. */
                         conn->ksnc_rx_ready = 0;
-                        spin_unlock_bh (&sched->kss_lock);
+                       spin_unlock_bh(&sched->kss_lock);
 
-                        rc = ksocknal_process_receive(conn);
+                       rc = ksocknal_process_receive(conn);
 
-                        spin_lock_bh (&sched->kss_lock);
+                       spin_lock_bh(&sched->kss_lock);
 
                         /* I'm the only one that can clear this flag */
                         LASSERT(conn->ksnc_rx_scheduled);
@@ -1576,8 +1446,8 @@ int ksocknal_scheduler (void *arg)
                                 conn->ksnc_rx_state = SOCKNAL_RX_PARSE_WAIT;
                         } else if (conn->ksnc_rx_ready) {
                                 /* reschedule for rx */
-                                list_add_tail (&conn->ksnc_rx_list,
-                                               &sched->kss_rx_conns);
+                               list_add_tail(&conn->ksnc_rx_list,
+                                                   &sched->kss_rx_conns);
                         } else {
                                 conn->ksnc_rx_scheduled = 0;
                                 /* drop my ref */
@@ -1587,40 +1457,41 @@ int ksocknal_scheduler (void *arg)
                         did_something = 1;
                 }
 
-                if (!list_empty (&sched->kss_tx_conns)) {
-                        CFS_LIST_HEAD    (zlist);
+               if (!list_empty(&sched->kss_tx_conns)) {
+                       struct list_head zlist = LIST_HEAD_INIT(zlist);
 
-                        if (!list_empty(&sched->kss_zombie_noop_txs)) {
-                                list_add(&zlist, &sched->kss_zombie_noop_txs);
-                                list_del_init(&sched->kss_zombie_noop_txs);
+                       if (!list_empty(&sched->kss_zombie_noop_txs)) {
+                               list_add(&zlist,
+                                             &sched->kss_zombie_noop_txs);
+                               list_del_init(&sched->kss_zombie_noop_txs);
                         }
 
-                        conn = list_entry(sched->kss_tx_conns.next,
-                                          ksock_conn_t, ksnc_tx_list);
-                        list_del (&conn->ksnc_tx_list);
+                       conn = list_entry(sched->kss_tx_conns.next,
+                                              ksock_conn_t, ksnc_tx_list);
+                       list_del(&conn->ksnc_tx_list);
 
                         LASSERT(conn->ksnc_tx_scheduled);
                         LASSERT(conn->ksnc_tx_ready);
-                        LASSERT(!list_empty(&conn->ksnc_tx_queue));
+                       LASSERT(!list_empty(&conn->ksnc_tx_queue));
 
-                        tx = list_entry(conn->ksnc_tx_queue.next,
-                                        ksock_tx_t, tx_list);
+                       tx = list_entry(conn->ksnc_tx_queue.next,
+                                            ksock_tx_t, tx_list);
 
-                        if (conn->ksnc_tx_mono == tx)
-                                ksocknal_next_mono_tx(conn);
+                        if (conn->ksnc_tx_carrier == tx)
+                                ksocknal_next_tx_carrier(conn);
 
                         /* dequeue now so empty list => more to send */
-                        list_del(&tx->tx_list);
+                       list_del(&tx->tx_list);
 
                         /* Clear tx_ready in case send isn't complete.  Do
                          * it BEFORE we call process_transmit, since
                          * write_space can set it any time after we release
                          * kss_lock. */
                         conn->ksnc_tx_ready = 0;
-                        spin_unlock_bh (&sched->kss_lock);
+                       spin_unlock_bh(&sched->kss_lock);
 
-                        if (!list_empty(&zlist)) {
-                                /* free zombie noop txs, it's fast because 
+                       if (!list_empty(&zlist)) {
+                               /* free zombie noop txs, it's fast because
                                  * noop txs are just put in freelist */
                                 ksocknal_txlist_done(NULL, &zlist, 0);
                         }
@@ -1629,13 +1500,14 @@ int ksocknal_scheduler (void *arg)
 
                         if (rc == -ENOMEM || rc == -EAGAIN) {
                                 /* Incomplete send: replace tx on HEAD of tx_queue */
-                                spin_lock_bh (&sched->kss_lock);
-                                list_add (&tx->tx_list, &conn->ksnc_tx_queue);
-                        } else {
-                                /* Complete send; tx -ref */
-                                ksocknal_tx_decref (tx);
-
-                                spin_lock_bh (&sched->kss_lock);
+                               spin_lock_bh(&sched->kss_lock);
+                               list_add(&tx->tx_list,
+                                            &conn->ksnc_tx_queue);
+                       } else {
+                               /* Complete send; tx -ref */
+                               ksocknal_tx_decref(tx);
+
+                               spin_lock_bh(&sched->kss_lock);
                                 /* assume space for more */
                                 conn->ksnc_tx_ready = 1;
                         }
@@ -1644,10 +1516,10 @@ int ksocknal_scheduler (void *arg)
                                 /* Do nothing; after a short timeout, this
                                  * conn will be reposted on kss_tx_conns. */
                         } else if (conn->ksnc_tx_ready &&
-                                   !list_empty (&conn->ksnc_tx_queue)) {
+                                  !list_empty(&conn->ksnc_tx_queue)) {
                                 /* reschedule for tx */
-                                list_add_tail (&conn->ksnc_tx_list,
-                                               &sched->kss_tx_conns);
+                               list_add_tail(&conn->ksnc_tx_list,
+                                                   &sched->kss_tx_conns);
                         } else {
                                 conn->ksnc_tx_scheduled = 0;
                                 /* drop my ref */
@@ -1658,27 +1530,27 @@ int ksocknal_scheduler (void *arg)
                 }
                 if (!did_something ||           /* nothing to do */
                     ++nloops == SOCKNAL_RESCHED) { /* hogging CPU? */
-                        spin_unlock_bh (&sched->kss_lock);
+                       spin_unlock_bh(&sched->kss_lock);
 
                         nloops = 0;
 
                         if (!did_something) {   /* wait for something to do */
-                                rc = wait_event_interruptible_exclusive(
-                                        sched->kss_waitq,
-                                        !ksocknal_sched_cansleep(sched));
-                                LASSERT (rc == 0);
-                        } else {
-                                our_cond_resched();
-                        }
-
-                        spin_lock_bh (&sched->kss_lock);
-                }
-        }
-
-        spin_unlock_bh (&sched->kss_lock);
-        ksocknal_thread_fini ();
-        return (0);
-}
+                               rc = wait_event_interruptible_exclusive(
+                                       sched->kss_waitq,
+                                       !ksocknal_sched_cansleep(sched));
+                               LASSERT (rc == 0);
+                       } else {
+                               cond_resched();
+                       }
+
+                       spin_lock_bh(&sched->kss_lock);
+               }
+       }
+
+       spin_unlock_bh(&sched->kss_lock);
+       ksocknal_thread_fini();
+       return 0;
+}
 
 /*
  * Add connection to kss_rx_conns of scheduler
@@ -1686,72 +1558,85 @@ int ksocknal_scheduler (void *arg)
  */
 void ksocknal_read_callback (ksock_conn_t *conn)
 {
-        ksock_sched_t *sched;
-        ENTRY;
+       ksock_sched_t *sched;
+       ENTRY;
 
-        sched = conn->ksnc_scheduler;
+       sched = conn->ksnc_scheduler;
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
 
-        conn->ksnc_rx_ready = 1;
+       conn->ksnc_rx_ready = 1;
 
-        if (!conn->ksnc_rx_scheduled) {  /* not being progressed */
-                list_add_tail(&conn->ksnc_rx_list,
-                              &sched->kss_rx_conns);
-                conn->ksnc_rx_scheduled = 1;
-                /* extra ref for scheduler */
-                ksocknal_conn_addref(conn);
+       if (!conn->ksnc_rx_scheduled) {  /* not being progressed */
+               list_add_tail(&conn->ksnc_rx_list,
+                                 &sched->kss_rx_conns);
+               conn->ksnc_rx_scheduled = 1;
+               /* extra ref for scheduler */
+               ksocknal_conn_addref(conn);
 
-                cfs_waitq_signal (&sched->kss_waitq);
-        }
-        spin_unlock_bh (&sched->kss_lock);
+               wake_up (&sched->kss_waitq);
+       }
+       spin_unlock_bh(&sched->kss_lock);
 
-        EXIT;
+       EXIT;
 }
 
 /*
  * Add connection to kss_tx_conns of scheduler
  * and wakeup the scheduler.
  */
-void ksocknal_write_callback (ksock_conn_t *conn)
+void ksocknal_write_callback(ksock_conn_t *conn)
 {
-        ksock_sched_t *sched;
-        ENTRY;
+       ksock_sched_t *sched;
+       ENTRY;
 
-        sched = conn->ksnc_scheduler;
+       sched = conn->ksnc_scheduler;
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
 
-        conn->ksnc_tx_ready = 1;
+       conn->ksnc_tx_ready = 1;
 
-        if (!conn->ksnc_tx_scheduled && // not being progressed 
-            !list_empty(&conn->ksnc_tx_queue)){//packets to send 
-                list_add_tail (&conn->ksnc_tx_list,
-                               &sched->kss_tx_conns);
-                conn->ksnc_tx_scheduled = 1;
-                /* extra ref for scheduler */
-                ksocknal_conn_addref(conn);
+       if (!conn->ksnc_tx_scheduled && /* not being progressed */
+           !list_empty(&conn->ksnc_tx_queue)) { /* packets to send */
+               list_add_tail(&conn->ksnc_tx_list, &sched->kss_tx_conns);
+               conn->ksnc_tx_scheduled = 1;
+               /* extra ref for scheduler */
+               ksocknal_conn_addref(conn);
 
-                cfs_waitq_signal (&sched->kss_waitq);
-        }
+               wake_up(&sched->kss_waitq);
+       }
 
-        spin_unlock_bh (&sched->kss_lock);
+       spin_unlock_bh(&sched->kss_lock);
 
-        EXIT;
+       EXIT;
 }
 
-ksock_proto_t *
+static ksock_proto_t *
 ksocknal_parse_proto_version (ksock_hello_msg_t *hello)
 {
-        if ((hello->kshm_magic   == LNET_PROTO_MAGIC &&
-             hello->kshm_version == KSOCK_PROTO_V2) ||
-            (hello->kshm_magic   == __swab32(LNET_PROTO_MAGIC) &&
-             hello->kshm_version == __swab32(KSOCK_PROTO_V2))) {
+        __u32   version = 0;
+
+        if (hello->kshm_magic == LNET_PROTO_MAGIC)
+                version = hello->kshm_version;
+        else if (hello->kshm_magic == __swab32(LNET_PROTO_MAGIC))
+                version = __swab32(hello->kshm_version);
+
+        if (version != 0) {
 #if SOCKNAL_VERSION_DEBUG
-                if (*ksocknal_tunables.ksnd_protocol != 2)
+                if (*ksocknal_tunables.ksnd_protocol == 1)
+                        return NULL;
+
+                if (*ksocknal_tunables.ksnd_protocol == 2 &&
+                    version == KSOCK_PROTO_V3)
                         return NULL;
 #endif
-                return &ksocknal_protocol_v2x;
+                if (version == KSOCK_PROTO_V2)
+                        return &ksocknal_protocol_v2x;
+
+                if (version == KSOCK_PROTO_V3)
+                        return &ksocknal_protocol_v3x;
+
+                return NULL;
         }
 
         if (hello->kshm_magic == le32_to_cpu(LNET_PROTO_TCP_MAGIC)) {
@@ -1768,349 +1653,19 @@ ksocknal_parse_proto_version (ksock_hello_msg_t *hello)
         return NULL;
 }
 
-static int
-ksocknal_send_hello_v1 (ksock_conn_t *conn, ksock_hello_msg_t *hello)
-{
-        cfs_socket_t        *sock = conn->ksnc_sock;
-        lnet_hdr_t          *hdr;
-        lnet_magicversion_t *hmv;
-        int                  rc;
-        int                  i;
-
-        CLASSERT(sizeof(lnet_magicversion_t) == offsetof(lnet_hdr_t, src_nid));
-
-        LIBCFS_ALLOC(hdr, sizeof(*hdr));
-        if (hdr == NULL) {
-                CERROR("Can't allocate lnet_hdr_t\n");
-                return -ENOMEM;
-        }
-
-        hmv = (lnet_magicversion_t *)&hdr->dest_nid;
-
-        /* Re-organize V2.x message header to V1.x (lnet_hdr_t)
-         * header and send out */
-        hmv->magic         = cpu_to_le32 (LNET_PROTO_TCP_MAGIC);
-        hmv->version_major = cpu_to_le16 (KSOCK_PROTO_V1_MAJOR);
-        hmv->version_minor = cpu_to_le16 (KSOCK_PROTO_V1_MINOR);
-
-        if (the_lnet.ln_testprotocompat != 0) {
-                /* single-shot proto check */
-                LNET_LOCK();
-                if ((the_lnet.ln_testprotocompat & 1) != 0) {
-                        hmv->version_major++;   /* just different! */
-                        the_lnet.ln_testprotocompat &= ~1;
-                }
-                if ((the_lnet.ln_testprotocompat & 2) != 0) {
-                        hmv->magic = LNET_PROTO_MAGIC;
-                        the_lnet.ln_testprotocompat &= ~2;
-                }
-                LNET_UNLOCK();
-        }
-
-        hdr->src_nid        = cpu_to_le64 (hello->kshm_src_nid);
-        hdr->src_pid        = cpu_to_le32 (hello->kshm_src_pid);
-        hdr->type           = cpu_to_le32 (LNET_MSG_HELLO);
-        hdr->payload_length = cpu_to_le32 (hello->kshm_nips * sizeof(__u32));
-        hdr->msg.hello.type = cpu_to_le32 (hello->kshm_ctype);
-        hdr->msg.hello.incarnation = cpu_to_le64 (hello->kshm_src_incarnation);
-
-        rc = libcfs_sock_write(sock, hdr, sizeof(*hdr), lnet_acceptor_timeout());
-
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO hdr to %u.%u.%u.%u/%d\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-                goto out;
-        }
-
-        if (hello->kshm_nips == 0)
-                goto out;
-
-        for (i = 0; i < hello->kshm_nips; i++) {
-                hello->kshm_ips[i] = __cpu_to_le32 (hello->kshm_ips[i]);
-        }
-
-        rc = libcfs_sock_write(sock, hello->kshm_ips,
-                               hello->kshm_nips * sizeof(__u32),
-                               lnet_acceptor_timeout());
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO payload (%d)"
-                        " to %u.%u.%u.%u/%d\n", rc, hello->kshm_nips,
-                        HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-        }
-out:
-        LIBCFS_FREE(hdr, sizeof(*hdr));
-
-        return rc;
-}
-
-static int
-ksocknal_send_hello_v2 (ksock_conn_t *conn, ksock_hello_msg_t *hello)
-{
-        cfs_socket_t   *sock = conn->ksnc_sock;
-        int             rc;
-
-        hello->kshm_magic       = LNET_PROTO_MAGIC;
-        hello->kshm_version     = KSOCK_PROTO_V2;
-
-        if (the_lnet.ln_testprotocompat != 0) {
-                /* single-shot proto check */
-                LNET_LOCK();
-                if ((the_lnet.ln_testprotocompat & 1) != 0) {
-                        hello->kshm_version++;   /* just different! */
-                        the_lnet.ln_testprotocompat &= ~1;
-                }
-                LNET_UNLOCK();
-        }
-
-        rc = libcfs_sock_write(sock, hello, offsetof(ksock_hello_msg_t, kshm_ips),
-                               lnet_acceptor_timeout());
-
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO hdr to %u.%u.%u.%u/%d\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-                return rc;
-        }
-
-        if (hello->kshm_nips == 0)
-                return 0;
-
-        rc = libcfs_sock_write(sock, hello->kshm_ips,
-                               hello->kshm_nips * sizeof(__u32),
-                               lnet_acceptor_timeout());
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO payload (%d)"
-                        " to %u.%u.%u.%u/%d\n", rc, hello->kshm_nips,
-                        HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-        }
-
-        return rc;
-}
-
-static int
-ksocknal_recv_hello_v1(ksock_conn_t *conn, ksock_hello_msg_t *hello,int timeout)
-{
-        cfs_socket_t        *sock = conn->ksnc_sock;
-        lnet_hdr_t          *hdr;
-        int                  rc;
-        int                  i;
-
-        LIBCFS_ALLOC(hdr, sizeof(*hdr));
-        if (hdr == NULL) {
-                CERROR("Can't allocate lnet_hdr_t\n");
-                return -ENOMEM;
-        }
-
-        rc = libcfs_sock_read(sock, &hdr->src_nid,
-                              sizeof (*hdr) - offsetof (lnet_hdr_t, src_nid),
-                              timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading rest of HELLO hdr from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                goto out;
-        }
-
-        /* ...and check we got what we expected */
-        if (hdr->type != cpu_to_le32 (LNET_MSG_HELLO)) {
-                CERROR ("Expecting a HELLO hdr,"
-                        " but got type %d from %u.%u.%u.%u\n",
-                        le32_to_cpu (hdr->type),
-                        HIPQUAD(conn->ksnc_ipaddr));
-                rc = -EPROTO;
-                goto out;
-        }
-
-        hello->kshm_src_nid         = le64_to_cpu (hdr->src_nid);
-        hello->kshm_src_pid         = le32_to_cpu (hdr->src_pid);
-        hello->kshm_src_incarnation = le64_to_cpu (hdr->msg.hello.incarnation);
-        hello->kshm_ctype           = le32_to_cpu (hdr->msg.hello.type);
-        hello->kshm_nips            = le32_to_cpu (hdr->payload_length) /
-                                         sizeof (__u32);
-
-        if (hello->kshm_nips > LNET_MAX_INTERFACES) {
-                CERROR("Bad nips %d from ip %u.%u.%u.%u\n",
-                       hello->kshm_nips, HIPQUAD(conn->ksnc_ipaddr));
-                rc = -EPROTO;
-                goto out;
-        }
-
-        if (hello->kshm_nips == 0)
-                goto out;
-
-        rc = libcfs_sock_read(sock, hello->kshm_ips,
-                              hello->kshm_nips * sizeof(__u32), timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading IPs from ip %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                goto out;
-        }
-
-        for (i = 0; i < hello->kshm_nips; i++) {
-                hello->kshm_ips[i] = __le32_to_cpu(hello->kshm_ips[i]);
-
-                if (hello->kshm_ips[i] == 0) {
-                        CERROR("Zero IP[%d] from ip %u.%u.%u.%u\n",
-                               i, HIPQUAD(conn->ksnc_ipaddr));
-                        rc = -EPROTO;
-                        break;
-                }
-        }
-out:
-        LIBCFS_FREE(hdr, sizeof(*hdr));
-
-        return rc;
-}
-
-static int
-ksocknal_recv_hello_v2 (ksock_conn_t *conn, ksock_hello_msg_t *hello, int timeout)
-{
-        cfs_socket_t      *sock = conn->ksnc_sock;
-        int                rc;
-        int                i;
-
-        if (hello->kshm_magic == LNET_PROTO_MAGIC)
-                conn->ksnc_flip = 0;
-        else
-                conn->ksnc_flip = 1;
-
-        rc = libcfs_sock_read(sock, &hello->kshm_src_nid,
-                              offsetof(ksock_hello_msg_t, kshm_ips) -
-                                       offsetof(ksock_hello_msg_t, kshm_src_nid),
-                              timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                return rc;
-        }
-
-        if (conn->ksnc_flip) {
-                __swab32s(&hello->kshm_src_pid);
-                __swab64s(&hello->kshm_src_nid);
-                __swab32s(&hello->kshm_dst_pid);
-                __swab64s(&hello->kshm_dst_nid);
-                __swab64s(&hello->kshm_src_incarnation);
-                __swab64s(&hello->kshm_dst_incarnation);
-                __swab32s(&hello->kshm_ctype);
-                __swab32s(&hello->kshm_nips);
-        }
-
-        if (hello->kshm_nips > LNET_MAX_INTERFACES) {
-                CERROR("Bad nips %d from ip %u.%u.%u.%u\n",
-                       hello->kshm_nips, HIPQUAD(conn->ksnc_ipaddr));
-                return -EPROTO;
-        }
-
-        if (hello->kshm_nips == 0)
-                return 0;
-
-        rc = libcfs_sock_read(sock, hello->kshm_ips,
-                              hello->kshm_nips * sizeof(__u32), timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading IPs from ip %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                return rc;
-        }
-
-        for (i = 0; i < hello->kshm_nips; i++) {
-                if (conn->ksnc_flip)
-                        __swab32s(&hello->kshm_ips[i]);
-
-                if (hello->kshm_ips[i] == 0) {
-                        CERROR("Zero IP[%d] from ip %u.%u.%u.%u\n",
-                               i, HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
-        }
-
-        return 0;
-}
-
-static void
-ksocknal_pack_msg_v1(ksock_tx_t *tx)
-{
-        /* V1.x has no KSOCK_MSG_NOOP */
-        LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
-        LASSERT(tx->tx_lnetmsg != NULL);
-
-        tx->tx_iov[0].iov_base = (void *)&tx->tx_lnetmsg->msg_hdr;
-        tx->tx_iov[0].iov_len  = sizeof(lnet_hdr_t);
-
-        tx->tx_resid = tx->tx_nob = tx->tx_lnetmsg->msg_len + sizeof(lnet_hdr_t);
-}
-
-static void
-ksocknal_pack_msg_v2(ksock_tx_t *tx)
-{
-        tx->tx_iov[0].iov_base = (void *)&tx->tx_msg;
-
-        if (tx->tx_lnetmsg != NULL) {
-                LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
-
-                tx->tx_msg.ksm_u.lnetmsg.ksnm_hdr = tx->tx_lnetmsg->msg_hdr;
-                tx->tx_iov[0].iov_len = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload);
-                tx->tx_resid = tx->tx_nob = offsetof(ksock_msg_t,  ksm_u.lnetmsg.ksnm_payload) +
-                                            tx->tx_lnetmsg->msg_len;
-        } else {
-                LASSERT(tx->tx_msg.ksm_type == KSOCK_MSG_NOOP);
-
-                tx->tx_iov[0].iov_len = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_hdr);
-                tx->tx_resid = tx->tx_nob = offsetof(ksock_msg_t,  ksm_u.lnetmsg.ksnm_hdr);
-        }
-        /* Don't checksum before start sending, because packet can be piggybacked with ACK */
-}
-
-static void
-ksocknal_unpack_msg_v1(ksock_msg_t *msg)
-{
-        msg->ksm_type           = KSOCK_MSG_LNET;
-        msg->ksm_csum           = 0;
-        msg->ksm_zc_req_cookie  = 0;
-        msg->ksm_zc_ack_cookie  = 0;
-}
-
-static void
-ksocknal_unpack_msg_v2(ksock_msg_t *msg)
-{
-        return;  /* Do nothing */
-}
-
-ksock_proto_t  ksocknal_protocol_v1x =
-{
-        KSOCK_PROTO_V1,
-        ksocknal_send_hello_v1,
-        ksocknal_recv_hello_v1,
-        ksocknal_pack_msg_v1,
-        ksocknal_unpack_msg_v1
-};
-
-ksock_proto_t  ksocknal_protocol_v2x =
-{
-        KSOCK_PROTO_V2,
-        ksocknal_send_hello_v2,
-        ksocknal_recv_hello_v2,
-        ksocknal_pack_msg_v2,
-        ksocknal_unpack_msg_v2
-};
-
 int
 ksocknal_send_hello (lnet_ni_t *ni, ksock_conn_t *conn,
                      lnet_nid_t peer_nid, ksock_hello_msg_t *hello)
 {
         /* CAVEAT EMPTOR: this byte flips 'ipaddrs' */
         ksock_net_t         *net = (ksock_net_t *)ni->ni_data;
-        lnet_nid_t           srcnid;
 
-        LASSERT (0 <= hello->kshm_nips && hello->kshm_nips <= LNET_MAX_INTERFACES);
+        LASSERT (hello->kshm_nips <= LNET_MAX_INTERFACES);
 
         /* rely on caller to hold a ref on socket so it wouldn't disappear */
         LASSERT (conn->ksnc_proto != NULL);
 
-        srcnid = lnet_ptlcompat_srcnid(ni->ni_nid, peer_nid);
-
-        hello->kshm_src_nid         = srcnid;
+        hello->kshm_src_nid         = ni->ni_nid;
         hello->kshm_dst_nid         = peer_nid;
         hello->kshm_src_pid         = the_lnet.ln_pid;
 
@@ -2120,7 +1675,7 @@ ksocknal_send_hello (lnet_ni_t *ni, ksock_conn_t *conn,
         return conn->ksnc_proto->pro_send_hello(conn, hello);
 }
 
-int
+static int
 ksocknal_invert_type(int type)
 {
         switch (type)
@@ -2147,7 +1702,7 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
          *        EALREADY   lost connection race
          *        EPROTO     protocol version mismatch
          */
-        cfs_socket_t        *sock = conn->ksnc_sock;
+       struct socket        *sock = conn->ksnc_sock;
         int                  active = (conn->ksnc_proto != NULL);
         int                  timeout;
         int                  proto_match;
@@ -2155,16 +1710,17 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
         ksock_proto_t       *proto;
         lnet_process_id_t    recv_id;
 
-        /* socket type set on active connections - not set on passive */
-        LASSERT (!active == !(conn->ksnc_type != SOCKLND_CONN_NONE));
+       /* socket type set on active connections - not set on passive */
+       LASSERT(!active == !(conn->ksnc_type != SOCKLND_CONN_NONE));
 
-        timeout = active ? *ksocknal_tunables.ksnd_timeout :
-                            lnet_acceptor_timeout();
+       timeout = active ? *ksocknal_tunables.ksnd_timeout :
+                           lnet_acceptor_timeout();
 
-        rc = libcfs_sock_read(sock, &hello->kshm_magic, sizeof (hello->kshm_magic), timeout);
+       rc = lnet_sock_read(sock, &hello->kshm_magic,
+                           sizeof(hello->kshm_magic), timeout);
         if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
+               CERROR("Error %d reading HELLO from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
                 LASSERT (rc < 0);
                 return rc;
         }
@@ -2173,50 +1729,18 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
             hello->kshm_magic != __swab32(LNET_PROTO_MAGIC) &&
             hello->kshm_magic != le32_to_cpu (LNET_PROTO_TCP_MAGIC)) {
                 /* Unexpected magic! */
-                if (active ||
-                    the_lnet.ln_ptlcompat == 0) {
-                        CERROR ("Bad magic(1) %#08x (%#08x expected) from "
-                                "%u.%u.%u.%u\n", __cpu_to_le32 (hello->kshm_magic),
-                                LNET_PROTO_TCP_MAGIC,
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
-
-                /* When portals compatibility is set, I may be passed a new
-                 * connection "blindly" by the acceptor, and I have to
-                 * determine if my peer has sent an acceptor connection request
-                 * or not.  This isn't a 'hello', so I'll get the acceptor to
-                 * look at it... */
-                rc = lnet_accept(ni, sock, hello->kshm_magic);
-                if (rc != 0)
-                        return -EPROTO;
-
-                /* ...and if it's OK I'm back to looking for a 'hello'... */
-                rc = libcfs_sock_read(sock, &hello->kshm_magic, 
-                                      sizeof (hello->kshm_magic), timeout);
-                if (rc != 0) {
-                        CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                                rc, HIPQUAD(conn->ksnc_ipaddr));
-                        LASSERT (rc < 0);
-                        return rc;
-                }
-
-                /* Only need to check V1.x magic */
-                if (hello->kshm_magic != le32_to_cpu (LNET_PROTO_TCP_MAGIC)) {
-                        CERROR ("Bad magic(2) %#08x (%#08x expected) from "
-                                "%u.%u.%u.%u\n", __cpu_to_le32 (hello->kshm_magic),
-                                LNET_PROTO_TCP_MAGIC,
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
+                CERROR ("Bad magic(1) %#08x (%#08x expected) from "
+                       "%pI4h\n", __cpu_to_le32 (hello->kshm_magic),
+                       LNET_PROTO_TCP_MAGIC, &conn->ksnc_ipaddr);
+                return -EPROTO;
         }
 
-        rc = libcfs_sock_read(sock, &hello->kshm_version,
-                              sizeof(hello->kshm_version), timeout);
+       rc = lnet_sock_read(sock, &hello->kshm_version,
+                           sizeof(hello->kshm_version), timeout);
         if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0);
+               CERROR("Error %d reading HELLO from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
+               LASSERT(rc < 0);
                 return rc;
         }
 
@@ -2224,19 +1748,19 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
         if (proto == NULL) {
                 if (!active) {
                         /* unknown protocol from peer, tell peer my protocol */
-                        conn->ksnc_proto = &ksocknal_protocol_v2x;
+                        conn->ksnc_proto = &ksocknal_protocol_v3x;
 #if SOCKNAL_VERSION_DEBUG
-                        if (*ksocknal_tunables.ksnd_protocol != 2)
+                        if (*ksocknal_tunables.ksnd_protocol == 2)
+                                conn->ksnc_proto = &ksocknal_protocol_v2x;
+                        else if (*ksocknal_tunables.ksnd_protocol == 1)
                                 conn->ksnc_proto = &ksocknal_protocol_v1x;
 #endif
                         hello->kshm_nips = 0;
                         ksocknal_send_hello(ni, conn, ni->ni_nid, hello);
                 }
 
-                CERROR ("Unknown protocol version (%d.x expected)"
-                        " from %u.%u.%u.%u\n",
-                        conn->ksnc_proto->pro_version,
-                        HIPQUAD(conn->ksnc_ipaddr));
+               CERROR("Unknown protocol version (%d.x expected) from %pI4h\n",
+                      conn->ksnc_proto->pro_version, &conn->ksnc_ipaddr);
 
                 return -EPROTO;
         }
@@ -2247,8 +1771,8 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
         /* receive the rest of hello message anyway */
         rc = conn->ksnc_proto->pro_recv_hello(conn, hello, timeout);
         if (rc != 0) {
-                CERROR("Error %d reading or checking hello from from %u.%u.%u.%u\n",
-                       rc, HIPQUAD(conn->ksnc_ipaddr));
+               CERROR("Error %d reading or checking hello from from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
                 LASSERT (rc < 0);
                 return rc;
         }
@@ -2257,7 +1781,7 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
 
         if (hello->kshm_src_nid == LNET_NID_ANY) {
                 CERROR("Expecting a HELLO hdr with a NID, but got LNET_NID_ANY"
-                       "from %u.%u.%u.%u\n", HIPQUAD(conn->ksnc_ipaddr));
+                      "from %pI4h\n", &conn->ksnc_ipaddr);
                 return -EPROTO;
         }
 
@@ -2268,38 +1792,31 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
                 recv_id.nid = LNET_MKNID(LNET_NIDNET(ni->ni_nid), conn->ksnc_ipaddr);
         } else {
                 recv_id.nid = hello->kshm_src_nid;
-
-                if (the_lnet.ln_ptlcompat > 1 && /* portals peers may exist */
-                    LNET_NIDNET(recv_id.nid) == 0) /* this is one */
-                        recv_id.pid = the_lnet.ln_pid; /* give it a sensible pid */
-                else
-                        recv_id.pid = hello->kshm_src_pid;
-
+                recv_id.pid = hello->kshm_src_pid;
         }
 
         if (!active) {
                 *peerid = recv_id;
 
-                /* peer determines type */
-                conn->ksnc_type = ksocknal_invert_type(hello->kshm_ctype);
-                if (conn->ksnc_type == SOCKLND_CONN_NONE) {
-                        CERROR ("Unexpected type %d from %s ip %u.%u.%u.%u\n",
-                                hello->kshm_ctype, libcfs_id2str(*peerid),
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
-
-                return 0;
-        }
+               /* peer determines type */
+               conn->ksnc_type = ksocknal_invert_type(hello->kshm_ctype);
+               if (conn->ksnc_type == SOCKLND_CONN_NONE) {
+                       CERROR("Unexpected type %d from %s ip %pI4h\n",
+                              hello->kshm_ctype, libcfs_id2str(*peerid),
+                              &conn->ksnc_ipaddr);
+                       return -EPROTO;
+               }
+               return 0;
+       }
 
         if (peerid->pid != recv_id.pid ||
-            !lnet_ptlcompat_matchnid(peerid->nid, recv_id.nid)) {
+            peerid->nid != recv_id.nid) {
                 LCONSOLE_ERROR_MSG(0x130, "Connected successfully to %s on host"
-                                   " %u.%u.%u.%u, but they claimed they were "
+                                  " %pI4h, but they claimed they were "
                                    "%s; please check your Lustre "
                                    "configuration.\n",
                                    libcfs_id2str(*peerid),
-                                   HIPQUAD(conn->ksnc_ipaddr),
+                                  &conn->ksnc_ipaddr,
                                    libcfs_id2str(recv_id));
                 return -EPROTO;
         }
@@ -2309,25 +1826,24 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
                 return proto_match ? EALREADY : EPROTO;
         }
 
-        if (ksocknal_invert_type(hello->kshm_ctype) != conn->ksnc_type) {
-                CERROR ("Mismatched types: me %d, %s ip %u.%u.%u.%u %d\n",
-                        conn->ksnc_type, libcfs_id2str(*peerid), 
-                        HIPQUAD(conn->ksnc_ipaddr),
-                        hello->kshm_ctype);
-                return -EPROTO;
-        }
-
-        return 0;
+       if (ksocknal_invert_type(hello->kshm_ctype) != conn->ksnc_type) {
+               CERROR("Mismatched types: me %d, %s ip %pI4h %d\n",
+                      conn->ksnc_type, libcfs_id2str(*peerid),
+                      &conn->ksnc_ipaddr,
+                      hello->kshm_ctype);
+               return -EPROTO;
+       }
+       return 0;
 }
 
-void
+static int
 ksocknal_connect (ksock_route_t *route)
 {
-        CFS_LIST_HEAD    (zombies);
+       struct list_head        zombies = LIST_HEAD_INIT(zombies);
         ksock_peer_t     *peer = route->ksnr_peer;
         int               type;
         int               wanted;
-        cfs_socket_t     *sock;
+       struct socket     *sock;
         cfs_time_t        deadline;
         int               retry_later = 0;
         int               rc = 0;
@@ -2335,7 +1851,7 @@ ksocknal_connect (ksock_route_t *route)
         deadline = cfs_time_add(cfs_time_current(),
                                 cfs_time_seconds(*ksocknal_tunables.ksnd_timeout));
 
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
 
         LASSERT (route->ksnr_scheduled);
         LASSERT (!route->ksnr_connecting);
@@ -2375,7 +1891,7 @@ ksocknal_connect (ksock_route_t *route)
                         type = SOCKLND_CONN_BULK_OUT;
                 }
 
-                write_unlock_bh (&ksocknal_data.ksnd_global_lock);
+               write_unlock_bh(&ksocknal_data.ksnd_global_lock);
 
                 if (cfs_time_aftereq(cfs_time_current(), deadline)) {
                         rc = -ETIMEDOUT;
@@ -2406,7 +1922,7 @@ ksocknal_connect (ksock_route_t *route)
                         CDEBUG(D_NET, "peer %s: conn race, retry later.\n",
                                libcfs_nid2str(peer->ksnp_id.nid));
 
-                write_lock_bh (&ksocknal_data.ksnd_global_lock);
+               write_lock_bh(&ksocknal_data.ksnd_global_lock);
         }
 
         route->ksnr_scheduled = 0;
@@ -2415,14 +1931,27 @@ ksocknal_connect (ksock_route_t *route)
         if (retry_later) {
                 /* re-queue for attention; this frees me up to handle
                  * the peer's incoming connection request */
+
+                if (rc == EALREADY ||
+                    (rc == 0 && peer->ksnp_accepting > 0)) {
+                        /* We want to introduce a delay before next
+                         * attempt to connect if we lost conn race,
+                         * but the race is resolved quickly usually,
+                         * so min_reconnectms should be good heuristic */
+                        route->ksnr_retry_interval =
+                                cfs_time_seconds(*ksocknal_tunables.ksnd_min_reconnectms)/1000;
+                        route->ksnr_timeout = cfs_time_add(cfs_time_current(),
+                                                           route->ksnr_retry_interval);
+                }
+
                 ksocknal_launch_connection_locked(route);
         }
 
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
-        return;
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+        return retry_later;
 
  failed:
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
 
         route->ksnr_scheduled = 0;
         route->ksnr_connecting = 0;
@@ -2440,165 +1969,322 @@ ksocknal_connect (ksock_route_t *route)
         route->ksnr_timeout = cfs_time_add(cfs_time_current(),
                                            route->ksnr_retry_interval);
 
-        if (!list_empty(&peer->ksnp_tx_queue) &&
+       if (!list_empty(&peer->ksnp_tx_queue) &&
             peer->ksnp_accepting == 0 &&
             ksocknal_find_connecting_route_locked(peer) == NULL) {
+                ksock_conn_t *conn;
+
                 /* ksnp_tx_queue is queued on a conn on successful
-                 * connection */
-                LASSERT (list_empty (&peer->ksnp_conns));
+                 * connection for V1.x and V2.x */
+               if (!list_empty(&peer->ksnp_conns)) {
+                       conn = list_entry(peer->ksnp_conns.next,
+                                              ksock_conn_t, ksnc_list);
+                        LASSERT (conn->ksnc_proto == &ksocknal_protocol_v3x);
+                }
 
                 /* take all the blocked packets while I've got the lock and
                  * complete below... */
-                list_add(&zombies, &peer->ksnp_tx_queue);
-                list_del_init(&peer->ksnp_tx_queue);
+               list_splice_init(&peer->ksnp_tx_queue, &zombies);
         }
 
 #if 0           /* irrelevent with only eager routes */
         if (!route->ksnr_deleted) {
                 /* make this route least-favourite for re-selection */
-                list_del(&route->ksnr_list);
-                list_add_tail(&route->ksnr_list, &peer->ksnp_routes);
+               list_del(&route->ksnr_list);
+               list_add_tail(&route->ksnr_list, &peer->ksnp_routes);
         }
 #endif
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
 
         ksocknal_peer_failed(peer);
         ksocknal_txlist_done(peer->ksnp_ni, &zombies, 1);
+        return 0;
 }
 
-static inline int
-ksocknal_connd_connect_route_locked(void)
+/*
+ * check whether we need to create more connds.
+ * It will try to create new thread if it's necessary, @timeout can
+ * be updated if failed to create, so caller wouldn't keep try while
+ * running out of resource.
+ */
+static int
+ksocknal_connd_check_start(long sec, long *timeout)
 {
-        /* Only handle an outgoing connection request if there is someone left
-         * to handle incoming connections */
-        return !list_empty(&ksocknal_data.ksnd_connd_routes) &&
-                ((ksocknal_data.ksnd_connd_connecting + 1) <
-                 *ksocknal_tunables.ksnd_nconnds);
+       char name[16];
+        int rc;
+        int total = ksocknal_data.ksnd_connd_starting +
+                    ksocknal_data.ksnd_connd_running;
+
+        if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+                /* still in initializing */
+                return 0;
+        }
+
+        if (total >= *ksocknal_tunables.ksnd_nconnds_max ||
+            total > ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV) {
+                /* can't create more connd, or still have enough
+                 * threads to handle more connecting */
+                return 0;
+        }
+
+        if (list_empty(&ksocknal_data.ksnd_connd_routes)) {
+                /* no pending connecting request */
+                return 0;
+        }
+
+        if (sec - ksocknal_data.ksnd_connd_failed_stamp <= 1) {
+                /* may run out of resource, retry later */
+                *timeout = cfs_time_seconds(1);
+                return 0;
+        }
+
+        if (ksocknal_data.ksnd_connd_starting > 0) {
+                /* serialize starting to avoid flood */
+                return 0;
+        }
+
+        ksocknal_data.ksnd_connd_starting_stamp = sec;
+        ksocknal_data.ksnd_connd_starting++;
+       spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
+
+       /* NB: total is the next id */
+       snprintf(name, sizeof(name), "socknal_cd%02d", total);
+       rc = ksocknal_thread_start(ksocknal_connd, NULL, name);
+
+       spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
+        if (rc == 0)
+                return 1;
+
+        /* we tried ... */
+        LASSERT(ksocknal_data.ksnd_connd_starting > 0);
+        ksocknal_data.ksnd_connd_starting--;
+        ksocknal_data.ksnd_connd_failed_stamp = cfs_time_current_sec();
+
+        return 1;
 }
 
-static inline int
-ksocknal_connd_ready(void)
+/*
+ * check whether current thread can exit, it will return 1 if there are too
+ * many threads and no creating in past 120 seconds.
+ * Also, this function may update @timeout to make caller come back
+ * again to recheck these conditions.
+ */
+static int
+ksocknal_connd_check_stop(long sec, long *timeout)
 {
-        int            rc;
+        int val;
+
+        if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+                /* still in initializing */
+                return 0;
+        }
 
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
+        if (ksocknal_data.ksnd_connd_starting > 0) {
+                /* in progress of starting new thread */
+                return 0;
+        }
+
+        if (ksocknal_data.ksnd_connd_running <=
+            *ksocknal_tunables.ksnd_nconnds) { /* can't shrink */
+                return 0;
+        }
 
-        rc = ksocknal_data.ksnd_shuttingdown ||
-             !list_empty(&ksocknal_data.ksnd_connd_connreqs) ||
-             ksocknal_connd_connect_route_locked();
+        /* created thread in past 120 seconds? */
+        val = (int)(ksocknal_data.ksnd_connd_starting_stamp +
+                    SOCKNAL_CONND_TIMEOUT - sec);
 
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+        *timeout = (val > 0) ? cfs_time_seconds(val) :
+                               cfs_time_seconds(SOCKNAL_CONND_TIMEOUT);
+        if (val > 0)
+                return 0;
+
+        /* no creating in past 120 seconds */
 
-        return rc;
+        return ksocknal_data.ksnd_connd_running >
+               ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV;
+}
+
+/* Go through connd_routes queue looking for a route that we can process
+ * right now, @timeout_p can be updated if we need to come back later */
+static ksock_route_t *
+ksocknal_connd_get_route_locked(signed long *timeout_p)
+{
+       ksock_route_t *route;
+       cfs_time_t     now;
+
+       now = cfs_time_current();
+
+       /* connd_routes can contain both pending and ordinary routes */
+       list_for_each_entry(route, &ksocknal_data.ksnd_connd_routes,
+                                ksnr_connd_list) {
+
+               if (route->ksnr_retry_interval == 0 ||
+                   cfs_time_aftereq(now, route->ksnr_timeout))
+                       return route;
+
+               if (*timeout_p == MAX_SCHEDULE_TIMEOUT ||
+                   (int)*timeout_p > (int)(route->ksnr_timeout - now))
+                       *timeout_p = (int)(route->ksnr_timeout - now);
+       }
+
+       return NULL;
 }
 
 int
 ksocknal_connd (void *arg)
 {
-        long               id = (long)arg;
-        char               name[16];
-        ksock_connreq_t   *cr;
-        ksock_route_t     *route;
+       spinlock_t    *connd_lock = &ksocknal_data.ksnd_connd_lock;
+       ksock_connreq_t   *cr;
+       wait_queue_t     wait;
+       int                nloops = 0;
+       int                cons_retry = 0;
 
-        snprintf (name, sizeof (name), "socknal_cd%02ld", id);
-        cfs_daemonize (name);
-        cfs_block_allsigs ();
+       cfs_block_allsigs();
 
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
+       init_waitqueue_entry(&wait, current);
 
-        while (!ksocknal_data.ksnd_shuttingdown) {
+       spin_lock_bh(connd_lock);
 
-                if (!list_empty(&ksocknal_data.ksnd_connd_connreqs)) {
-                        /* Connection accepted by the listener */
-                        cr = list_entry(ksocknal_data.ksnd_connd_connreqs.next,
-                                        ksock_connreq_t, ksncr_list);
+       LASSERT(ksocknal_data.ksnd_connd_starting > 0);
+       ksocknal_data.ksnd_connd_starting--;
+       ksocknal_data.ksnd_connd_running++;
 
-                        list_del(&cr->ksncr_list);
-                        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+       while (!ksocknal_data.ksnd_shuttingdown) {
+               ksock_route_t *route = NULL;
+               long sec = cfs_time_current_sec();
+               long timeout = MAX_SCHEDULE_TIMEOUT;
+               int  dropped_lock = 0;
 
-                        ksocknal_create_conn(cr->ksncr_ni, NULL,
-                                             cr->ksncr_sock, SOCKLND_CONN_NONE);
-                        lnet_ni_decref(cr->ksncr_ni);
-                        LIBCFS_FREE(cr, sizeof(*cr));
+               if (ksocknal_connd_check_stop(sec, &timeout)) {
+                       /* wakeup another one to check stop */
+                       wake_up(&ksocknal_data.ksnd_connd_waitq);
+                       break;
+               }
 
-                        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
+                if (ksocknal_connd_check_start(sec, &timeout)) {
+                        /* created new thread */
+                        dropped_lock = 1;
                 }
 
-                if (ksocknal_connd_connect_route_locked()) {
-                        /* Connection request */
-                        route = list_entry (ksocknal_data.ksnd_connd_routes.next,
-                                            ksock_route_t, ksnr_connd_list);
+               if (!list_empty(&ksocknal_data.ksnd_connd_connreqs)) {
+                        /* Connection accepted by the listener */
+                       cr = list_entry(ksocknal_data.ksnd_connd_connreqs. \
+                                            next, ksock_connreq_t, ksncr_list);
 
-                        list_del (&route->ksnr_connd_list);
-                        ksocknal_data.ksnd_connd_connecting++;
-                        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+                       list_del(&cr->ksncr_list);
+                       spin_unlock_bh(connd_lock);
+                       dropped_lock = 1;
 
-                        ksocknal_connect (route);
-                        ksocknal_route_decref(route);
+                       ksocknal_create_conn(cr->ksncr_ni, NULL,
+                                            cr->ksncr_sock, SOCKLND_CONN_NONE);
+                       lnet_ni_decref(cr->ksncr_ni);
+                       LIBCFS_FREE(cr, sizeof(*cr));
 
-                        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-                        ksocknal_data.ksnd_connd_connecting--;
+                       spin_lock_bh(connd_lock);
                 }
 
-                spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
-
-                wait_event_interruptible_exclusive(
-                        ksocknal_data.ksnd_connd_waitq,
-                        ksocknal_connd_ready());
-
-                spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-        }
+                /* Only handle an outgoing connection request if there
+                 * is a thread left to handle incoming connections and
+                 * create new connd */
+                if (ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV <
+                    ksocknal_data.ksnd_connd_running) {
+                        route = ksocknal_connd_get_route_locked(&timeout);
+                }
+                if (route != NULL) {
+                       list_del(&route->ksnr_connd_list);
+                        ksocknal_data.ksnd_connd_connecting++;
+                       spin_unlock_bh(connd_lock);
+                        dropped_lock = 1;
+
+                        if (ksocknal_connect(route)) {
+                                /* consecutive retry */
+                                if (cons_retry++ > SOCKNAL_INSANITY_RECONN) {
+                                        CWARN("massive consecutive "
+                                             "re-connecting to %pI4h\n",
+                                             &route->ksnr_ipaddr);
+                                        cons_retry = 0;
+                                }
+                        } else {
+                                cons_retry = 0;
+                        }
 
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+                        ksocknal_route_decref(route);
 
-        ksocknal_thread_fini ();
-        return (0);
+                       spin_lock_bh(connd_lock);
+                       ksocknal_data.ksnd_connd_connecting--;
+               }
+
+               if (dropped_lock) {
+                       if (++nloops < SOCKNAL_RESCHED)
+                               continue;
+                       spin_unlock_bh(connd_lock);
+                       nloops = 0;
+                       cond_resched();
+                       spin_lock_bh(connd_lock);
+                       continue;
+               }
+
+               /* Nothing to do for 'timeout'  */
+               set_current_state(TASK_INTERRUPTIBLE);
+               add_wait_queue_exclusive(&ksocknal_data.ksnd_connd_waitq, &wait);
+               spin_unlock_bh(connd_lock);
+
+               nloops = 0;
+               schedule_timeout(timeout);
+
+               set_current_state(TASK_RUNNING);
+               remove_wait_queue(&ksocknal_data.ksnd_connd_waitq, &wait);
+               spin_lock_bh(connd_lock);
+       }
+       ksocknal_data.ksnd_connd_running--;
+       spin_unlock_bh(connd_lock);
+
+       ksocknal_thread_fini();
+       return 0;
 }
 
-ksock_conn_t *
+static ksock_conn_t *
 ksocknal_find_timed_out_conn (ksock_peer_t *peer)
 {
         /* We're called with a shared lock on ksnd_global_lock */
         ksock_conn_t      *conn;
-        struct list_head  *ctmp;
+       struct list_head        *ctmp;
 
-        list_for_each (ctmp, &peer->ksnp_conns) {
+       list_for_each(ctmp, &peer->ksnp_conns) {
                 int     error;
-                conn = list_entry (ctmp, ksock_conn_t, ksnc_list);
+               conn = list_entry(ctmp, ksock_conn_t, ksnc_list);
 
                 /* Don't need the {get,put}connsock dance to deref ksnc_sock */
                 LASSERT (!conn->ksnc_closing);
 
-                /* SOCK_ERROR will reset error code of socket in
-                 * some platform (like Darwin8.x) */
-                error = SOCK_ERROR(conn->ksnc_sock);
+               error = conn->ksnc_sock->sk->sk_err;
                 if (error != 0) {
                         ksocknal_conn_addref(conn);
 
                         switch (error) {
                         case ECONNRESET:
-                                CDEBUG(D_NETERROR, "A connection with %s "
-                                       "(%u.%u.%u.%u:%d) was reset; "
-                                       "it may have rebooted.\n",
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("A connection with %s "
+                                       "(%pI4h:%d) was reset; "
+                                        "it may have rebooted.\n",
+                                        libcfs_id2str(peer->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         case ETIMEDOUT:
-                                CDEBUG(D_NETERROR, "A connection with %s "
-                                       "(%u.%u.%u.%u:%d) timed out; the "
-                                       "network or node may be down.\n",
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("A connection with %s "
+                                       "(%pI4h:%d) timed out; the "
+                                        "network or node may be down.\n",
+                                        libcfs_id2str(peer->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         default:
-                                CDEBUG(D_NETERROR, "An unexpected network error %d "
-                                       "occurred with %s "
-                                       "(%u.%u.%u.%u:%d\n", error,
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("An unexpected network error %d "
+                                        "occurred with %s "
+                                       "(%pI4h:%d\n", error,
+                                        libcfs_id2str(peer->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         }
 
@@ -2610,30 +2296,28 @@ ksocknal_find_timed_out_conn (ksock_peer_t *peer)
                                      conn->ksnc_rx_deadline)) {
                         /* Timed out incomplete incoming message */
                         ksocknal_conn_addref(conn);
-                        CDEBUG(D_NETERROR, "Timeout receiving from %s "
-                               "(%u.%u.%u.%u:%d), state %d wanted %d left %d\n",
-                               libcfs_id2str(peer->ksnp_id),
-                               HIPQUAD(conn->ksnc_ipaddr),
-                               conn->ksnc_port,
-                               conn->ksnc_rx_state,
-                               conn->ksnc_rx_nob_wanted,
-                               conn->ksnc_rx_nob_left);
+                       CNETERR("Timeout receiving from %s (%pI4h:%d), "
+                                "state %d wanted %d left %d\n",
+                                libcfs_id2str(peer->ksnp_id),
+                               &conn->ksnc_ipaddr,
+                                conn->ksnc_port,
+                                conn->ksnc_rx_state,
+                                conn->ksnc_rx_nob_wanted,
+                                conn->ksnc_rx_nob_left);
                         return (conn);
                 }
 
-                if ((!list_empty(&conn->ksnc_tx_queue) ||
-                     SOCK_WMEM_QUEUED(conn->ksnc_sock) != 0) &&
+               if ((!list_empty(&conn->ksnc_tx_queue) ||
+                    conn->ksnc_sock->sk->sk_wmem_queued != 0) &&
                     cfs_time_aftereq(cfs_time_current(),
                                      conn->ksnc_tx_deadline)) {
                         /* Timed out messages queued for sending or
                          * buffered in the socket's send buffer */
                         ksocknal_conn_addref(conn);
-                        CDEBUG(D_NETERROR, "Timeout sending data to %s "
-                               "(%u.%u.%u.%u:%d) the network or that "
-                               "node may be down.\n",
-                               libcfs_id2str(peer->ksnp_id),
-                               HIPQUAD(conn->ksnc_ipaddr),
-                               conn->ksnc_port);
+                       CNETERR("Timeout sending data to %s (%pI4h:%d) "
+                                "the network or that node may be down.\n",
+                                libcfs_id2str(peer->ksnp_id),
+                               &conn->ksnc_ipaddr, conn->ksnc_port);
                         return (conn);
                 }
         }
@@ -2641,26 +2325,123 @@ ksocknal_find_timed_out_conn (ksock_peer_t *peer)
         return (NULL);
 }
 
-void
+static inline void
+ksocknal_flush_stale_txs(ksock_peer_t *peer)
+{
+        ksock_tx_t        *tx;
+       struct list_head        stale_txs = LIST_HEAD_INIT(stale_txs);
+
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
+
+       while (!list_empty(&peer->ksnp_tx_queue)) {
+               tx = list_entry(peer->ksnp_tx_queue.next,
+                                     ksock_tx_t, tx_list);
+
+                if (!cfs_time_aftereq(cfs_time_current(),
+                                      tx->tx_deadline))
+                        break;
+
+               list_del(&tx->tx_list);
+               list_add_tail(&tx->tx_list, &stale_txs);
+        }
+
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+
+        ksocknal_txlist_done(peer->ksnp_ni, &stale_txs, 1);
+}
+
+static int
+ksocknal_send_keepalive_locked(ksock_peer_t *peer)
+__must_hold(&ksocknal_data.ksnd_global_lock)
+{
+        ksock_sched_t  *sched;
+        ksock_conn_t   *conn;
+        ksock_tx_t     *tx;
+
+       /* last_alive will be updated by create_conn */
+       if (list_empty(&peer->ksnp_conns))
+                return 0;
+
+        if (peer->ksnp_proto != &ksocknal_protocol_v3x)
+                return 0;
+
+        if (*ksocknal_tunables.ksnd_keepalive <= 0 ||
+            cfs_time_before(cfs_time_current(),
+                            cfs_time_add(peer->ksnp_last_alive,
+                                         cfs_time_seconds(*ksocknal_tunables.ksnd_keepalive))))
+                return 0;
+
+        if (cfs_time_before(cfs_time_current(),
+                            peer->ksnp_send_keepalive))
+                return 0;
+
+        /* retry 10 secs later, so we wouldn't put pressure
+         * on this peer if we failed to send keepalive this time */
+        peer->ksnp_send_keepalive = cfs_time_shift(10);
+
+        conn = ksocknal_find_conn_locked(peer, NULL, 1);
+        if (conn != NULL) {
+                sched = conn->ksnc_scheduler;
+
+               spin_lock_bh(&sched->kss_lock);
+               if (!list_empty(&conn->ksnc_tx_queue)) {
+                       spin_unlock_bh(&sched->kss_lock);
+                       /* there is an queued ACK, don't need keepalive */
+                       return 0;
+               }
+
+               spin_unlock_bh(&sched->kss_lock);
+       }
+
+       read_unlock(&ksocknal_data.ksnd_global_lock);
+
+       /* cookie = 1 is reserved for keepalive PING */
+       tx = ksocknal_alloc_tx_noop(1, 1);
+       if (tx == NULL) {
+               read_lock(&ksocknal_data.ksnd_global_lock);
+               return -ENOMEM;
+       }
+
+       if (ksocknal_launch_packet(peer->ksnp_ni, tx, peer->ksnp_id) == 0) {
+               read_lock(&ksocknal_data.ksnd_global_lock);
+               return 1;
+       }
+
+       ksocknal_free_tx(tx);
+       read_lock(&ksocknal_data.ksnd_global_lock);
+
+       return -EIO;
+}
+
+
+static void
 ksocknal_check_peer_timeouts (int idx)
 {
-        struct list_head *peers = &ksocknal_data.ksnd_peers[idx];
-        struct list_head *ptmp;
+       struct list_head       *peers = &ksocknal_data.ksnd_peers[idx];
         ksock_peer_t     *peer;
         ksock_conn_t     *conn;
+        ksock_tx_t       *tx;
 
  again:
         /* NB. We expect to have a look at all the peers and not find any
          * connections to time out, so we just use a shared lock while we
          * take a look... */
-        read_lock (&ksocknal_data.ksnd_global_lock);
+       read_lock(&ksocknal_data.ksnd_global_lock);
+
+       list_for_each_entry(peer, peers, ksnp_list) {
+                cfs_time_t  deadline = 0;
+                int         resid = 0;
+                int         n     = 0;
+
+                if (ksocknal_send_keepalive_locked(peer) != 0) {
+                       read_unlock(&ksocknal_data.ksnd_global_lock);
+                        goto again;
+                }
 
-        list_for_each (ptmp, peers) {
-                peer = list_entry (ptmp, ksock_peer_t, ksnp_list);
                 conn = ksocknal_find_timed_out_conn (peer);
 
                 if (conn != NULL) {
-                        read_unlock (&ksocknal_data.ksnd_global_lock);
+                       read_unlock(&ksocknal_data.ksnd_global_lock);
 
                         ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
 
@@ -2670,85 +2451,146 @@ ksocknal_check_peer_timeouts (int idx)
                         ksocknal_conn_decref(conn);
                         goto again;
                 }
+
+                /* we can't process stale txs right here because we're
+                 * holding only shared lock */
+               if (!list_empty(&peer->ksnp_tx_queue)) {
+                        ksock_tx_t *tx =
+                               list_entry(peer->ksnp_tx_queue.next,
+                                                ksock_tx_t, tx_list);
+
+                        if (cfs_time_aftereq(cfs_time_current(),
+                                             tx->tx_deadline)) {
+
+                                ksocknal_peer_addref(peer);
+                               read_unlock(&ksocknal_data.ksnd_global_lock);
+
+                                ksocknal_flush_stale_txs(peer);
+
+                                ksocknal_peer_decref(peer);
+                                goto again;
+                        }
+                }
+
+               if (list_empty(&peer->ksnp_zc_req_list))
+                        continue;
+
+               spin_lock(&peer->ksnp_lock);
+               list_for_each_entry(tx, &peer->ksnp_zc_req_list, tx_zc_list) {
+                        if (!cfs_time_aftereq(cfs_time_current(),
+                                              tx->tx_deadline))
+                                break;
+                        /* ignore the TX if connection is being closed */
+                        if (tx->tx_conn->ksnc_closing)
+                                continue;
+                        n++;
+                }
+
+                if (n == 0) {
+                       spin_unlock(&peer->ksnp_lock);
+                        continue;
+                }
+
+               tx = list_entry(peer->ksnp_zc_req_list.next,
+                                    ksock_tx_t, tx_zc_list);
+                deadline = tx->tx_deadline;
+                resid    = tx->tx_resid;
+                conn     = tx->tx_conn;
+                ksocknal_conn_addref(conn);
+
+               spin_unlock(&peer->ksnp_lock);
+               read_unlock(&ksocknal_data.ksnd_global_lock);
+
+                CERROR("Total %d stale ZC_REQs for peer %s detected; the "
+                       "oldest(%p) timed out %ld secs ago, "
+                       "resid: %d, wmem: %d\n",
+                       n, libcfs_nid2str(peer->ksnp_id.nid), tx,
+                       cfs_duration_sec(cfs_time_current() - deadline),
+                      resid, conn->ksnc_sock->sk->sk_wmem_queued);
+
+                ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
+                ksocknal_conn_decref(conn);
+                goto again;
         }
 
-        read_unlock (&ksocknal_data.ksnd_global_lock);
+       read_unlock(&ksocknal_data.ksnd_global_lock);
 }
 
-int
-ksocknal_reaper (void *arg)
+int ksocknal_reaper(void *arg)
 {
-        cfs_waitlink_t     wait;
-        ksock_conn_t      *conn;
-        ksock_sched_t     *sched;
-        struct list_head   enomem_conns;
+       wait_queue_t     wait;
+       ksock_conn_t      *conn;
+       ksock_sched_t     *sched;
+       struct list_head         enomem_conns;
         int                nenomem_conns;
         cfs_duration_t     timeout;
         int                i;
         int                peer_index = 0;
         cfs_time_t         deadline = cfs_time_current();
 
-        cfs_daemonize ("socknal_reaper");
         cfs_block_allsigs ();
 
-        CFS_INIT_LIST_HEAD(&enomem_conns);
-        cfs_waitlink_init (&wait);
+       INIT_LIST_HEAD(&enomem_conns);
+       init_waitqueue_entry(&wait, current);
 
-        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
 
         while (!ksocknal_data.ksnd_shuttingdown) {
 
-                if (!list_empty (&ksocknal_data.ksnd_deathrow_conns)) {
-                        conn = list_entry (ksocknal_data.ksnd_deathrow_conns.next,
-                                           ksock_conn_t, ksnc_list);
-                        list_del (&conn->ksnc_list);
+               if (!list_empty(&ksocknal_data.ksnd_deathrow_conns)) {
+                       conn = list_entry(ksocknal_data. \
+                                               ksnd_deathrow_conns.next,
+                                               ksock_conn_t, ksnc_list);
+                       list_del(&conn->ksnc_list);
 
-                        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-                        ksocknal_terminate_conn (conn);
-                        ksocknal_conn_decref(conn);
+                       ksocknal_terminate_conn(conn);
+                       ksocknal_conn_decref(conn);
 
-                        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
                         continue;
                 }
 
-                if (!list_empty (&ksocknal_data.ksnd_zombie_conns)) {
-                        conn = list_entry (ksocknal_data.ksnd_zombie_conns.next,
-                                           ksock_conn_t, ksnc_list);
-                        list_del (&conn->ksnc_list);
+               if (!list_empty(&ksocknal_data.ksnd_zombie_conns)) {
+                       conn = list_entry(ksocknal_data.ksnd_zombie_conns.\
+                                               next, ksock_conn_t, ksnc_list);
+                       list_del(&conn->ksnc_list);
 
-                        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-                        ksocknal_destroy_conn (conn);
+                       ksocknal_destroy_conn(conn);
 
-                        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
                         continue;
                 }
 
-                if (!list_empty (&ksocknal_data.ksnd_enomem_conns)) {
-                        list_add(&enomem_conns, &ksocknal_data.ksnd_enomem_conns);
-                        list_del_init(&ksocknal_data.ksnd_enomem_conns);
+               if (!list_empty(&ksocknal_data.ksnd_enomem_conns)) {
+                       list_add(&enomem_conns,
+                                     &ksocknal_data.ksnd_enomem_conns);
+                       list_del_init(&ksocknal_data.ksnd_enomem_conns);
                 }
 
-                spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+               spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
                 /* reschedule all the connections that stalled with ENOMEM... */
                 nenomem_conns = 0;
-                while (!list_empty (&enomem_conns)) {
-                        conn = list_entry (enomem_conns.next,
-                                           ksock_conn_t, ksnc_tx_list);
-                        list_del (&conn->ksnc_tx_list);
+               while (!list_empty(&enomem_conns)) {
+                       conn = list_entry(enomem_conns.next,
+                                               ksock_conn_t, ksnc_tx_list);
+                       list_del(&conn->ksnc_tx_list);
 
                         sched = conn->ksnc_scheduler;
 
-                        spin_lock_bh (&sched->kss_lock);
+                       spin_lock_bh(&sched->kss_lock);
 
-                        LASSERT (conn->ksnc_tx_scheduled);
-                        conn->ksnc_tx_ready = 1;
-                        list_add_tail(&conn->ksnc_tx_list, &sched->kss_tx_conns);
-                        cfs_waitq_signal (&sched->kss_waitq);
+                       LASSERT(conn->ksnc_tx_scheduled);
+                       conn->ksnc_tx_ready = 1;
+                       list_add_tail(&conn->ksnc_tx_list,
+                                         &sched->kss_tx_conns);
+                       wake_up(&sched->kss_waitq);
 
-                        spin_unlock_bh (&sched->kss_lock);
+                       spin_unlock_bh(&sched->kss_lock);
                         nenomem_conns++;
                 }
 
@@ -2790,22 +2632,22 @@ ksocknal_reaper (void *arg)
                 ksocknal_data.ksnd_reaper_waketime =
                         cfs_time_add(cfs_time_current(), timeout);
 
-                set_current_state (TASK_INTERRUPTIBLE);
-                cfs_waitq_add (&ksocknal_data.ksnd_reaper_waitq, &wait);
+                       set_current_state(TASK_INTERRUPTIBLE);
+               add_wait_queue(&ksocknal_data.ksnd_reaper_waitq, &wait);
 
-                if (!ksocknal_data.ksnd_shuttingdown &&
-                    list_empty (&ksocknal_data.ksnd_deathrow_conns) &&
-                    list_empty (&ksocknal_data.ksnd_zombie_conns))
-                        cfs_waitq_timedwait (&wait, CFS_TASK_INTERRUPTIBLE, timeout);
+               if (!ksocknal_data.ksnd_shuttingdown &&
+                   list_empty(&ksocknal_data.ksnd_deathrow_conns) &&
+                   list_empty(&ksocknal_data.ksnd_zombie_conns))
+                       schedule_timeout(timeout);
 
-                set_current_state (TASK_RUNNING);
-                cfs_waitq_del (&ksocknal_data.ksnd_reaper_waitq, &wait);
+               set_current_state(TASK_RUNNING);
+               remove_wait_queue(&ksocknal_data.ksnd_reaper_waitq, &wait);
 
-                spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
-        }
+               spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
+       }
 
-        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-        ksocknal_thread_fini ();
-        return (0);
+       ksocknal_thread_fini();
+       return 0;
 }