LU-12646 lnet: Prefer route specified by rtr_nid

Restore an optimization that was initially added under LU-11413. For
routed REPLY and ACK we should preferably use the same router from
which the GET/PUT was receieved.

Cray-bug-id: LUS-8008
Test-Parameters: trivial
Signed-off-by: Chris Horn <hornc@cray.com>
Change-Id: Ia3059cddf70e1c477d90acdd90c13b4c5a292f4f
Reviewed-on: https://review.whamcloud.com/35737
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lnet/lnet/lib-move.c b/lnet/lnet/lib-move.c
index 262e432..3d9bed4 100644 (file)
--- a/lnet/lnet/lib-move.c
+++ b/lnet/lnet/lib-move.c
@@ -1516,7 +1516,7 @@ lnet_compare_routes(struct lnet_route *r1, struct lnet_route *r2,
 
 static struct lnet_route *
 lnet_find_route_locked(struct lnet_net *net, __u32 remote_net,
 
 static struct lnet_route *
 lnet_find_route_locked(struct lnet_net *net, __u32 remote_net,

-                      lnet_nid_t rtr_nid, struct lnet_route **prev_route,
+                      struct lnet_route **prev_route,

                       struct lnet_peer_ni **gwni)
 {
        struct lnet_peer_ni *best_gw_ni = NULL;
                       struct lnet_peer_ni **gwni)
 {
        struct lnet_peer_ni *best_gw_ni = NULL;


@@ -1528,9 +1528,6 @@ lnet_find_route_locked(struct lnet_net *net, __u32 remote_net,
        struct lnet_peer *lp;
        int rc;
 
        struct lnet_peer *lp;
        int rc;
 

-       /* If @rtr_nid is not LNET_NID_ANY, return the gateway with
-        * rtr_nid nid, otherwise find the best gateway I can use */
-

        rnet = lnet_find_rnet_locked(remote_net);
        if (rnet == NULL)
                return NULL;
        rnet = lnet_find_rnet_locked(remote_net);
        if (rnet == NULL)
                return NULL;


@@ -1847,13 +1844,14 @@ lnet_handle_send(struct lnet_send_data *sd)
        rc = lnet_post_send_locked(msg, 0);
 
        if (!rc)
        rc = lnet_post_send_locked(msg, 0);
 
        if (!rc)

-               CDEBUG(D_NET, "TRACE: %s(%s:%s) -> %s(%s:%s) : %s try# %d\n",
+               CDEBUG(D_NET, "TRACE: %s(%s:%s) -> %s(%s:%s) %s : %s try# %d\n",

                       libcfs_nid2str(msg->msg_hdr.src_nid),
                       libcfs_nid2str(msg->msg_txni->ni_nid),
                       libcfs_nid2str(sd->sd_src_nid),
                       libcfs_nid2str(msg->msg_hdr.dest_nid),
                       libcfs_nid2str(sd->sd_dst_nid),
                       libcfs_nid2str(msg->msg_txpeer->lpni_nid),
                       libcfs_nid2str(msg->msg_hdr.src_nid),
                       libcfs_nid2str(msg->msg_txni->ni_nid),
                       libcfs_nid2str(sd->sd_src_nid),
                       libcfs_nid2str(msg->msg_hdr.dest_nid),
                       libcfs_nid2str(sd->sd_dst_nid),
                       libcfs_nid2str(msg->msg_txpeer->lpni_nid),

+                      libcfs_nid2str(sd->sd_rtr_nid),

                       lnet_msgtyp2str(msg->msg_type), msg->msg_retry_count);
 
        return rc;
                       lnet_msgtyp2str(msg->msg_type), msg->msg_retry_count);
 
        return rc;


@@ -2028,69 +2026,90 @@ lnet_handle_find_routed_path(struct lnet_send_data *sd,
                             struct lnet_peer **gw_peer)
 {
        int rc;
                             struct lnet_peer **gw_peer)
 {
        int rc;

+       __u32 local_lnet;

        struct lnet_peer *gw;
        struct lnet_peer *lp;
        struct lnet_peer_net *lpn;
        struct lnet_peer_net *best_lpn = NULL;
        struct lnet_remotenet *rnet;
        struct lnet_peer *gw;
        struct lnet_peer *lp;
        struct lnet_peer_net *lpn;
        struct lnet_peer_net *best_lpn = NULL;
        struct lnet_remotenet *rnet;

-       struct lnet_route *best_route;
-       struct lnet_route *last_route;
+       struct lnet_route *best_route = NULL;
+       struct lnet_route *last_route = NULL;

        struct lnet_peer_ni *lpni = NULL;
        struct lnet_peer_ni *gwni = NULL;
        lnet_nid_t src_nid = sd->sd_src_nid;
 
        struct lnet_peer_ni *lpni = NULL;
        struct lnet_peer_ni *gwni = NULL;
        lnet_nid_t src_nid = sd->sd_src_nid;
 

-       /* we've already looked up the initial lpni using dst_nid */
-       lpni = sd->sd_best_lpni;
-       /* the peer tree must be in existence */
-       LASSERT(lpni && lpni->lpni_peer_net && lpni->lpni_peer_net->lpn_peer);
-       lp = lpni->lpni_peer_net->lpn_peer;
+       /* If a router nid was specified then we are replying to a GET or
+        * sending an ACK. In this case we use the gateway associated with the
+        * specified router nid.
+        */
+       if (sd->sd_rtr_nid != LNET_NID_ANY) {
+               gwni = lnet_find_peer_ni_locked(sd->sd_rtr_nid);
+               if (!gwni) {
+                       CERROR("No peer NI for gateway %s\n",
+                              libcfs_nid2str(sd->sd_rtr_nid));
+                       return -EHOSTUNREACH;
+               }
+               gw = gwni->lpni_peer_net->lpn_peer;
+               lnet_peer_ni_decref_locked(gwni);
+               local_lnet = LNET_NIDNET(sd->sd_rtr_nid);
+       } else {
+               /* we've already looked up the initial lpni using dst_nid */
+               lpni = sd->sd_best_lpni;
+               /* the peer tree must be in existence */
+               LASSERT(lpni && lpni->lpni_peer_net &&
+                       lpni->lpni_peer_net->lpn_peer);
+               lp = lpni->lpni_peer_net->lpn_peer;
+
+               list_for_each_entry(lpn, &lp->lp_peer_nets, lpn_peer_nets) {
+                       /* is this remote network reachable?  */
+                       rnet = lnet_find_rnet_locked(lpn->lpn_net_id);
+                       if (!rnet)
+                               continue;

 
 

-       list_for_each_entry(lpn, &lp->lp_peer_nets, lpn_peer_nets) {
-               /* is this remote network reachable?  */
-               rnet = lnet_find_rnet_locked(lpn->lpn_net_id);
-               if (!rnet)
-                       continue;
+                       if (!best_lpn)
+                               best_lpn = lpn;
+
+                       if (best_lpn->lpn_seq <= lpn->lpn_seq)
+                               continue;

 
 

-               if (!best_lpn)

                        best_lpn = lpn;
                        best_lpn = lpn;

+               }

 
 

-               if (best_lpn->lpn_seq <= lpn->lpn_seq)
-                       continue;
+               if (!best_lpn) {
+                       CERROR("peer %s has no available nets\n",
+                              libcfs_nid2str(sd->sd_dst_nid));
+                       return -EHOSTUNREACH;
+               }

 
 

-               best_lpn = lpn;
-       }
+               sd->sd_best_lpni = lnet_find_best_lpni_on_net(sd, lp, best_lpn->lpn_net_id);
+               if (!sd->sd_best_lpni) {
+                       CERROR("peer %s down\n",
+                              libcfs_nid2str(sd->sd_dst_nid));
+                       return -EHOSTUNREACH;
+               }

 
 

-       if (!best_lpn) {
-               CERROR("peer %s has no available nets \n",
-                      libcfs_nid2str(sd->sd_dst_nid));
-               return -EHOSTUNREACH;
-       }
+               best_route = lnet_find_route_locked(NULL, best_lpn->lpn_net_id,
+                                                   &last_route, &gwni);
+               if (!best_route) {
+                       CERROR("no route to %s from %s\n",
+                              libcfs_nid2str(dst_nid),
+                              libcfs_nid2str(src_nid));
+                       return -EHOSTUNREACH;
+               }

 
 

-       sd->sd_best_lpni = lnet_find_best_lpni_on_net(sd, lp, best_lpn->lpn_net_id);
-       if (!sd->sd_best_lpni) {
-               CERROR("peer %s down\n", libcfs_nid2str(sd->sd_dst_nid));
-               return -EHOSTUNREACH;
-       }
+               if (!gwni) {
+                       CERROR("Internal Error. Route expected to %s from %s\n",
+                              libcfs_nid2str(dst_nid),
+                              libcfs_nid2str(src_nid));
+                       return -EFAULT;
+               }

 
 

-       best_route = lnet_find_route_locked(NULL, best_lpn->lpn_net_id,
-                                           sd->sd_rtr_nid, &last_route,
-                                           &gwni);
-       if (!best_route) {
-               CERROR("no route to %s from %s\n",
-                      libcfs_nid2str(dst_nid), libcfs_nid2str(src_nid));
-               return -EHOSTUNREACH;
-       }
+               gw = best_route->lr_gateway;
+               LASSERT(gw == gwni->lpni_peer_net->lpn_peer);
+               local_lnet = best_route->lr_lnet;

 
 

-       if (!gwni) {
-               CERROR("Internal Error. Route expected to %s from %s\n",
-                       libcfs_nid2str(dst_nid),
-                       libcfs_nid2str(src_nid));
-               return -EFAULT;

        }
 
        }
 

-       gw = best_route->lr_gateway;
-       LASSERT(gw == gwni->lpni_peer_net->lpn_peer);
-

        /*
         * Discover this gateway if it hasn't already been discovered.
         * This means we might delay the message until discovery has
        /*
         * Discover this gateway if it hasn't already been discovered.
         * This means we might delay the message until discovery has


@@ -2105,14 +2124,13 @@ lnet_handle_find_routed_path(struct lnet_send_data *sd,
        if (!sd->sd_best_ni)
                sd->sd_best_ni = lnet_find_best_ni_on_spec_net(NULL, gw,
                                        lnet_peer_get_net_locked(gw,
        if (!sd->sd_best_ni)
                sd->sd_best_ni = lnet_find_best_ni_on_spec_net(NULL, gw,
                                        lnet_peer_get_net_locked(gw,

-                                               best_route->lr_lnet),
+                                                                local_lnet),

                                        sd->sd_md_cpt,
                                        true);
 
        if (!sd->sd_best_ni) {
                                        sd->sd_md_cpt,
                                        true);
 
        if (!sd->sd_best_ni) {

-               CERROR("Internal Error. Expected local ni on %s "
-                      "but non found :%s\n",
-                      libcfs_net2str(best_route->lr_lnet),
+               CERROR("Internal Error. Expected local ni on %s but non found :%s\n",
+                      libcfs_net2str(local_lnet),

                       libcfs_nid2str(sd->sd_src_nid));
                return -EFAULT;
        }
                       libcfs_nid2str(sd->sd_src_nid));
                return -EFAULT;
        }


@@ -2124,9 +2142,11 @@ lnet_handle_find_routed_path(struct lnet_send_data *sd,
         * increment the sequence numbers since now we're sure we're
         * going to use this path
         */
         * increment the sequence numbers since now we're sure we're
         * going to use this path
         */

-       LASSERT(best_route && last_route);
-       best_route->lr_seq = last_route->lr_seq + 1;
-       best_lpn->lpn_seq++;
+       if (sd->sd_rtr_nid == LNET_NID_ANY) {
+               LASSERT(best_route && last_route);
+               best_route->lr_seq = last_route->lr_seq + 1;
+               best_lpn->lpn_seq++;
+       }

 
        return 0;
 }
 
        return 0;
 }

diff --git a/lnet/lnet/lib-msg.c b/lnet/lnet/lib-msg.c
index fcf021a..84bf23d 100644 (file)
--- a/lnet/lnet/lib-msg.c
+++ b/lnet/lnet/lib-msg.c
@@ -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);
 
                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);
                rc = lnet_send(msg->msg_ev.target.nid, msg, msg->msg_from);
 
                lnet_net_lock(cpt);