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LU-12646 lnet: Prefer route specified by rtr_nid
[fs/lustre-release.git] / lnet / lnet / lib-msg.c
index 19c9e77..84bf23d 100644 (file)
@@ -391,8 +391,6 @@ lnet_complete_msg_locked(struct lnet_msg *msg, int cpt)
                msg->msg_hdr.msg.ack.match_bits = msg->msg_ev.match_bits;
                msg->msg_hdr.msg.ack.mlength = cpu_to_le32(msg->msg_ev.mlength);
 
-               /* NB: we probably want to use NID of msg::msg_from as 3rd
-                * parameter (router NID) if it's routed message */
                rc = lnet_send(msg->msg_ev.target.nid, msg, msg->msg_from);
 
                lnet_net_lock(cpt);
@@ -593,6 +591,174 @@ lnet_incr_hstats(struct lnet_msg *msg, enum lnet_msg_hstatus hstatus)
        }
 }
 
+static void
+lnet_resend_msg_locked(struct lnet_msg *msg)
+{
+       msg->msg_retry_count++;
+
+       /*
+        * remove message from the active list and reset it to prepare
+        * for a resend. Two exceptions to this
+        *
+        * 1. the router case. When a message is being routed it is
+        * committed for rx when received and committed for tx when
+        * forwarded. We don't want to remove it from the active list, since
+        * code which handles receiving expects it to remain on the active
+        * list.
+        *
+        * 2. The REPLY case. Reply messages use the same message
+        * structure for the GET that was received.
+        */
+       if (!msg->msg_routing && msg->msg_type != LNET_MSG_REPLY) {
+               list_del_init(&msg->msg_activelist);
+               msg->msg_onactivelist = 0;
+       }
+       /*
+        * The msg_target.nid which was originally set
+        * when calling LNetGet() or LNetPut() might've
+        * been overwritten if we're routing this message.
+        * Call lnet_msg_decommit_tx() to return the credit
+        * this message consumed. The message will
+        * consume another credit when it gets resent.
+        */
+       msg->msg_target.nid = msg->msg_hdr.dest_nid;
+       lnet_msg_decommit_tx(msg, -EAGAIN);
+       msg->msg_sending = 0;
+       msg->msg_receiving = 0;
+       msg->msg_target_is_router = 0;
+
+       CDEBUG(D_NET, "%s->%s:%s:%s - queuing msg (%p) for resend\n",
+              libcfs_nid2str(msg->msg_hdr.src_nid),
+              libcfs_nid2str(msg->msg_hdr.dest_nid),
+              lnet_msgtyp2str(msg->msg_type),
+              lnet_health_error2str(msg->msg_health_status), msg);
+
+       list_add_tail(&msg->msg_list, the_lnet.ln_mt_resendqs[msg->msg_tx_cpt]);
+
+       complete(&the_lnet.ln_mt_wait_complete);
+}
+
+int
+lnet_check_finalize_recursion_locked(struct lnet_msg *msg,
+                                    struct list_head *containerq,
+                                    int nworkers, void **workers)
+{
+       int my_slot = -1;
+       int i;
+
+       list_add_tail(&msg->msg_list, containerq);
+
+       for (i = 0; i < nworkers; i++) {
+               if (workers[i] == current)
+                       break;
+
+               if (my_slot < 0 && workers[i] == NULL)
+                       my_slot = i;
+       }
+
+       if (i < nworkers || my_slot < 0)
+               return -1;
+
+       workers[my_slot] = current;
+
+       return my_slot;
+}
+
+int
+lnet_attempt_msg_resend(struct lnet_msg *msg)
+{
+       struct lnet_msg_container *container;
+       int my_slot;
+       int cpt;
+
+       /* we can only resend tx_committed messages */
+       LASSERT(msg->msg_tx_committed);
+
+       /* don't resend recovery messages */
+       if (msg->msg_recovery) {
+               CDEBUG(D_NET, "msg %s->%s is a recovery ping. retry# %d\n",
+                       libcfs_nid2str(msg->msg_from),
+                       libcfs_nid2str(msg->msg_target.nid),
+                       msg->msg_retry_count);
+               return -ENOTRECOVERABLE;
+       }
+
+       /*
+        * if we explicitly indicated we don't want to resend then just
+        * return
+        */
+       if (msg->msg_no_resend) {
+               CDEBUG(D_NET, "msg %s->%s requested no resend. retry# %d\n",
+                       libcfs_nid2str(msg->msg_from),
+                       libcfs_nid2str(msg->msg_target.nid),
+                       msg->msg_retry_count);
+               return -ENOTRECOVERABLE;
+       }
+
+       /* check if the message has exceeded the number of retries */
+       if (msg->msg_retry_count >= lnet_retry_count) {
+               CNETERR("msg %s->%s exceeded retry count %d\n",
+                       libcfs_nid2str(msg->msg_from),
+                       libcfs_nid2str(msg->msg_target.nid),
+                       msg->msg_retry_count);
+               return -ENOTRECOVERABLE;
+       }
+
+       cpt = msg->msg_tx_cpt;
+       lnet_net_lock(cpt);
+
+       /* check again under lock */
+       if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING) {
+               lnet_net_unlock(cpt);
+               return -ESHUTDOWN;
+       }
+
+       container = the_lnet.ln_msg_containers[cpt];
+       my_slot =
+               lnet_check_finalize_recursion_locked(msg,
+                                       &container->msc_resending,
+                                       container->msc_nfinalizers,
+                                       container->msc_resenders);
+
+       /* enough threads are resending */
+       if (my_slot == -1) {
+               lnet_net_unlock(cpt);
+               return 0;
+       }
+
+       while (!list_empty(&container->msc_resending)) {
+               msg = list_entry(container->msc_resending.next,
+                                       struct lnet_msg, msg_list);
+               list_del(&msg->msg_list);
+
+               /*
+                * resending the message will require us to call
+                * lnet_msg_decommit_tx() which will return the credit
+                * which this message holds. This could trigger another
+                * queued message to be sent. If that message fails and
+                * requires a resend we will recurse.
+                * But since at this point the slot is taken, the message
+                * will be queued in the container and dealt with
+                * later. This breaks the recursion.
+                */
+               lnet_resend_msg_locked(msg);
+       }
+
+       /*
+        * msc_resenders is an array of process pointers. Each entry holds
+        * a pointer to the current process operating on the message. An
+        * array entry is created per CPT. If the array slot is already
+        * set, then it means that there is a thread on the CPT currently
+        * resending a message.
+        * Once the thread finishes clear the slot to enable the thread to
+        * take on more resend work.
+        */
+       container->msc_resenders[my_slot] = NULL;
+       lnet_net_unlock(cpt);
+
+       return 0;
+}
+
 /*
  * Do a health check on the message:
  * return -1 if we're not going to handle the error or
@@ -604,9 +770,9 @@ static int
 lnet_health_check(struct lnet_msg *msg)
 {
        enum lnet_msg_hstatus hstatus = msg->msg_health_status;
-       bool lo = false;
-       struct lnet_ni *ni;
        struct lnet_peer_ni *lpni;
+       struct lnet_ni *ni;
+       bool lo = false;
 
        /* if we're shutting down no point in handling health. */
        if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING)
@@ -700,7 +866,7 @@ lnet_health_check(struct lnet_msg *msg)
                lnet_handle_local_failure(ni);
                if (msg->msg_tx_committed)
                        /* add to the re-send queue */
-                       goto resend;
+                       return lnet_attempt_msg_resend(msg);
                break;
 
        /*
@@ -718,7 +884,7 @@ lnet_health_check(struct lnet_msg *msg)
        case LNET_MSG_STATUS_REMOTE_DROPPED:
                lnet_handle_remote_failure(lpni);
                if (msg->msg_tx_committed)
-                       goto resend;
+                       return lnet_attempt_msg_resend(msg);
                break;
 
        case LNET_MSG_STATUS_REMOTE_ERROR:
@@ -730,89 +896,8 @@ lnet_health_check(struct lnet_msg *msg)
                LBUG();
        }
 
-resend:
-       /* we can only resend tx_committed messages */
-       LASSERT(msg->msg_tx_committed);
-
-       /* don't resend recovery messages */
-       if (msg->msg_recovery) {
-               CDEBUG(D_NET, "msg %s->%s is a recovery ping. retry# %d\n",
-                       libcfs_nid2str(msg->msg_from),
-                       libcfs_nid2str(msg->msg_target.nid),
-                       msg->msg_retry_count);
-               return -1;
-       }
-
-       /*
-        * if we explicitly indicated we don't want to resend then just
-        * return
-        */
-       if (msg->msg_no_resend) {
-               CDEBUG(D_NET, "msg %s->%s requested no resend. retry# %d\n",
-                       libcfs_nid2str(msg->msg_from),
-                       libcfs_nid2str(msg->msg_target.nid),
-                       msg->msg_retry_count);
-               return -1;
-       }
-
-       /* check if the message has exceeded the number of retries */
-       if (msg->msg_retry_count >= lnet_retry_count) {
-               CNETERR("msg %s->%s exceeded retry count %d\n",
-                       libcfs_nid2str(msg->msg_from),
-                       libcfs_nid2str(msg->msg_target.nid),
-                       msg->msg_retry_count);
-               return -1;
-       }
-       msg->msg_retry_count++;
-
-       lnet_net_lock(msg->msg_tx_cpt);
-
-       /* check again under lock */
-       if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING) {
-               lnet_net_unlock(msg->msg_tx_cpt);
-               return -1;
-       }
-
-       /*
-        * remove message from the active list and reset it in preparation
-        * for a resend. Two exception to this
-        *
-        * 1. the router case, whe a message is committed for rx when
-        * received, then tx when it is sent. When committed to both tx and
-        * rx we don't want to remove it from the active list.
-        *
-        * 2. The REPLY case since it uses the same msg block for the GET
-        * that was received.
-        */
-       if (!msg->msg_routing && msg->msg_type != LNET_MSG_REPLY) {
-               list_del_init(&msg->msg_activelist);
-               msg->msg_onactivelist = 0;
-       }
-       /*
-        * The msg_target.nid which was originally set
-        * when calling LNetGet() or LNetPut() might've
-        * been overwritten if we're routing this message.
-        * Call lnet_return_tx_credits_locked() to return
-        * the credit this message consumed. The message will
-        * consume another credit when it gets resent.
-        */
-       msg->msg_target.nid = msg->msg_hdr.dest_nid;
-       lnet_msg_decommit_tx(msg, -EAGAIN);
-       msg->msg_sending = 0;
-       msg->msg_receiving = 0;
-       msg->msg_target_is_router = 0;
-
-       CDEBUG(D_NET, "%s->%s:%s:%s - queuing for resend\n",
-              libcfs_nid2str(msg->msg_hdr.src_nid),
-              libcfs_nid2str(msg->msg_hdr.dest_nid),
-              lnet_msgtyp2str(msg->msg_type),
-              lnet_health_error2str(hstatus));
-
-       list_add_tail(&msg->msg_list, the_lnet.ln_mt_resendqs[msg->msg_tx_cpt]);
-       lnet_net_unlock(msg->msg_tx_cpt);
-
-       wake_up(&the_lnet.ln_mt_waitq);
-       return 0;
+       /* no resend is needed */
+       return -1;
 }
 
 static void
@@ -951,7 +1036,6 @@ lnet_finalize(struct lnet_msg *msg, int status)
        int my_slot;
        int cpt;
        int rc;
-       int i;
 
        LASSERT(!in_interrupt());
 
@@ -974,7 +1058,6 @@ lnet_finalize(struct lnet_msg *msg, int status)
                 * put on the resend queue.
                 */
                if (!lnet_health_check(msg))
-                       /* Message is queued for resend */
                        return;
        }
 
@@ -1006,27 +1089,20 @@ again:
        lnet_net_lock(cpt);
 
        container = the_lnet.ln_msg_containers[cpt];
-       list_add_tail(&msg->msg_list, &container->msc_finalizing);
 
        /* Recursion breaker.  Don't complete the message here if I am (or
         * enough other threads are) already completing messages */
+       my_slot = lnet_check_finalize_recursion_locked(msg,
+                                               &container->msc_finalizing,
+                                               container->msc_nfinalizers,
+                                               container->msc_finalizers);
 
-       my_slot = -1;
-       for (i = 0; i < container->msc_nfinalizers; i++) {
-               if (container->msc_finalizers[i] == current)
-                       break;
-
-               if (my_slot < 0 && container->msc_finalizers[i] == NULL)
-                       my_slot = i;
-       }
-
-       if (i < container->msc_nfinalizers || my_slot < 0) {
+       /* enough threads are resending */
+       if (my_slot == -1) {
                lnet_net_unlock(cpt);
                return;
        }
 
-       container->msc_finalizers[my_slot] = current;
-
        rc = 0;
        while (!list_empty(&container->msc_finalizing)) {
                msg = list_entry(container->msc_finalizing.next,
@@ -1084,6 +1160,13 @@ lnet_msg_container_cleanup(struct lnet_msg_container *container)
                            sizeof(*container->msc_finalizers));
                container->msc_finalizers = NULL;
        }
+
+       if (container->msc_resenders != NULL) {
+               LIBCFS_FREE(container->msc_resenders,
+                           container->msc_nfinalizers *
+                           sizeof(*container->msc_resenders));
+               container->msc_resenders = NULL;
+       }
        container->msc_init = 0;
 }
 
@@ -1096,6 +1179,7 @@ lnet_msg_container_setup(struct lnet_msg_container *container, int cpt)
 
        INIT_LIST_HEAD(&container->msc_active);
        INIT_LIST_HEAD(&container->msc_finalizing);
+       INIT_LIST_HEAD(&container->msc_resending);
 
        /* number of CPUs */
        container->msc_nfinalizers = cfs_cpt_weight(lnet_cpt_table(), cpt);
@@ -1112,6 +1196,16 @@ lnet_msg_container_setup(struct lnet_msg_container *container, int cpt)
                return -ENOMEM;
        }
 
+       LIBCFS_CPT_ALLOC(container->msc_resenders, lnet_cpt_table(), cpt,
+                        container->msc_nfinalizers *
+                        sizeof(*container->msc_resenders));
+
+       if (container->msc_resenders == NULL) {
+               CERROR("Failed to allocate message resenders\n");
+               lnet_msg_container_cleanup(container);
+               return -ENOMEM;
+       }
+
        return rc;
 }