[lustre-devel] [PATCH 343/622] lnet: MR aware gateway selection
James Simmons
jsimmons at infradead.org
Thu Feb 27 13:13:31 PST 2020
From: Amir Shehata <ashehata at whamcloud.com>
When selecting a route use the Multi-Rail Selection algorithm to
select the best available peer_ni of the best route. The selected
peer_ni can then be used to send the message or to discover it
if the gateway peer needs discovering.
WC-bug-id: https://jira.whamcloud.com/browse/LU-11378
Lustre-commit: 11d8380d5ad0 ("LU-11378 lnet: MR aware gateway selection")
Signed-off-by: Amir Shehata <ashehata at whamcloud.com>
Reviewed-on: https://review.whamcloud.com/33188
Reviewed-by: Olaf Weber <olaf.weber at hpe.com>
Signed-off-by: James Simmons <jsimmons at infradead.org>
---
net/lnet/lnet/lib-move.c | 353 +++++++++++++++++++++++------------------------
1 file changed, 171 insertions(+), 182 deletions(-)
diff --git a/net/lnet/lnet/lib-move.c b/net/lnet/lnet/lib-move.c
index e214a95..054ae48 100644
--- a/net/lnet/lnet/lib-move.c
+++ b/net/lnet/lnet/lib-move.c
@@ -1117,7 +1117,6 @@ void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
}
}
-#if 0
static int
lnet_compare_peers(struct lnet_peer_ni *p1, struct lnet_peer_ni *p2)
{
@@ -1135,53 +1134,189 @@ void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
return 0;
}
-#endif
+
+static struct lnet_peer_ni *
+lnet_select_peer_ni(struct lnet_ni *best_ni, lnet_nid_t dst_nid,
+ struct lnet_peer *peer,
+ struct lnet_peer_net *peer_net)
+{
+ /* Look at the peer NIs for the destination peer that connect
+ * to the chosen net. If a peer_ni is preferred when using the
+ * best_ni to communicate, we use that one. If there is no
+ * preferred peer_ni, or there are multiple preferred peer_ni,
+ * the available transmit credits are used. If the transmit
+ * credits are equal, we round-robin over the peer_ni.
+ */
+ struct lnet_peer_ni *lpni = NULL;
+ struct lnet_peer_ni *best_lpni = NULL;
+ int best_lpni_credits = INT_MIN;
+ bool preferred = false;
+ bool ni_is_pref;
+ int best_lpni_healthv = 0;
+ int lpni_healthv;
+
+ while ((lpni = lnet_get_next_peer_ni_locked(peer, peer_net, lpni))) {
+ /* if the best_ni we've chosen aleady has this lpni
+ * preferred, then let's use it
+ */
+ if (best_ni) {
+ ni_is_pref = lnet_peer_is_pref_nid_locked(lpni,
+ best_ni->ni_nid);
+ CDEBUG(D_NET, "%s ni_is_pref = %d\n",
+ libcfs_nid2str(best_ni->ni_nid), ni_is_pref);
+ } else {
+ ni_is_pref = false;
+ }
+
+ lpni_healthv = atomic_read(&lpni->lpni_healthv);
+
+ if (best_lpni)
+ CDEBUG(D_NET, "%s c:[%d, %d], s:[%d, %d]\n",
+ libcfs_nid2str(lpni->lpni_nid),
+ lpni->lpni_txcredits, best_lpni_credits,
+ lpni->lpni_seq, best_lpni->lpni_seq);
+
+ /* pick the healthiest peer ni */
+ if (lpni_healthv < best_lpni_healthv) {
+ continue;
+ } else if (lpni_healthv > best_lpni_healthv) {
+ best_lpni_healthv = lpni_healthv;
+ /* if this is a preferred peer use it */
+ } else if (!preferred && ni_is_pref) {
+ preferred = true;
+ } else if (preferred && !ni_is_pref) {
+ /* this is not the preferred peer so let's ignore
+ * it.
+ */
+ continue;
+ } else if (lpni->lpni_txcredits < best_lpni_credits) {
+ /* We already have a peer that has more credits
+ * available than this one. No need to consider
+ * this peer further.
+ */
+ continue;
+ } else if (lpni->lpni_txcredits == best_lpni_credits) {
+ /* The best peer found so far and the current peer
+ * have the same number of available credits let's
+ * make sure to select between them using Round
+ * Robin
+ */
+ if (best_lpni) {
+ if (best_lpni->lpni_seq <= lpni->lpni_seq)
+ continue;
+ }
+ }
+
+ best_lpni = lpni;
+ best_lpni_credits = lpni->lpni_txcredits;
+ }
+
+ /* if we still can't find a peer ni then we can't reach it */
+ if (!best_lpni) {
+ u32 net_id = (peer_net) ? peer_net->lpn_net_id :
+ LNET_NIDNET(dst_nid);
+ CDEBUG(D_NET, "no peer_ni found on peer net %s\n",
+ libcfs_net2str(net_id));
+ return NULL;
+ }
+
+ CDEBUG(D_NET, "sd_best_lpni = %s\n",
+ libcfs_nid2str(best_lpni->lpni_nid));
+
+ return best_lpni;
+}
+
+/* Prerequisite: the best_ni should already be set in the sd */
+static inline struct lnet_peer_ni *
+lnet_find_best_lpni_on_net(struct lnet_send_data *sd, struct lnet_peer *peer,
+ u32 net_id)
+{
+ struct lnet_peer_net *peer_net;
+
+ /* The gateway is Multi-Rail capable so now we must select the
+ * proper peer_ni
+ */
+ peer_net = lnet_peer_get_net_locked(peer, net_id);
+
+ if (!peer_net) {
+ CERROR("gateway peer %s has no NI on net %s\n",
+ libcfs_nid2str(peer->lp_primary_nid),
+ libcfs_net2str(net_id));
+ return NULL;
+ }
+
+ return lnet_select_peer_ni(sd->sd_best_ni, sd->sd_dst_nid,
+ peer, peer_net);
+}
static int
-lnet_compare_routes(struct lnet_route *r1, struct lnet_route *r2)
+lnet_compare_routes(struct lnet_route *r1, struct lnet_route *r2,
+ struct lnet_peer_ni **best_lpni)
{
- /* TODO re-implement gateway comparison
- struct lnet_peer_ni *p1 = r1->lr_gateway;
- struct lnet_peer_ni *p2 = r2->lr_gateway;
- */
int r1_hops = (r1->lr_hops == LNET_UNDEFINED_HOPS) ? 1 : r1->lr_hops;
int r2_hops = (r2->lr_hops == LNET_UNDEFINED_HOPS) ? 1 : r2->lr_hops;
- /*int rc;*/
+ struct lnet_peer *lp1 = r1->lr_gateway;
+ struct lnet_peer *lp2 = r2->lr_gateway;
+ struct lnet_peer_ni *lpni1;
+ struct lnet_peer_ni *lpni2;
+ struct lnet_send_data sd;
+ int rc;
+
+ sd.sd_best_ni = NULL;
+ sd.sd_dst_nid = LNET_NID_ANY;
+ lpni1 = lnet_find_best_lpni_on_net(&sd, lp1, r1->lr_lnet);
+ lpni2 = lnet_find_best_lpni_on_net(&sd, lp2, r2->lr_lnet);
+ LASSERT(lpni1 && lpni2);
- if (r1->lr_priority < r2->lr_priority)
+ if (r1->lr_priority < r2->lr_priority) {
+ *best_lpni = lpni1;
return 1;
+ }
- if (r1->lr_priority > r2->lr_priority)
+ if (r1->lr_priority > r2->lr_priority) {
+ *best_lpni = lpni2;
return -1;
+ }
- if (r1_hops < r2_hops)
+ if (r1_hops < r2_hops) {
+ *best_lpni = lpni1;
return 1;
+ }
- if (r1_hops > r2_hops)
+ if (r1_hops > r2_hops) {
+ *best_lpni = lpni2;
return -1;
+ }
- /*
- rc = lnet_compare_peers(p1, p2);
- if (rc)
+ rc = lnet_compare_peers(lpni1, lpni2);
+ if (rc == 1) {
+ *best_lpni = lpni1;
+ return rc;
+ } else if (rc == -1) {
+ *best_lpni = lpni2;
return rc;
- */
+ }
- if (r1->lr_seq - r2->lr_seq <= 0)
+ if (r1->lr_seq - r2->lr_seq <= 0) {
+ *best_lpni = lpni1;
return 1;
+ }
+ *best_lpni = lpni2;
return -1;
}
-/* TODO: lnet_find_route_locked() needs to be reimplemented */
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)
+ lnet_nid_t rtr_nid, struct lnet_route **prev_route,
+ struct lnet_peer_ni **gwni)
{
- struct lnet_remotenet *rnet;
- struct lnet_route *route;
+ struct lnet_peer_ni *best_gw_ni = NULL;
struct lnet_route *best_route;
struct lnet_route *last_route;
+ struct lnet_remotenet *rnet;
struct lnet_peer *lp_best;
+ struct lnet_route *route;
struct lnet_peer *lp;
int rc;
@@ -1206,14 +1341,13 @@ void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
best_route = route;
last_route = route;
lp_best = lp;
- continue;
}
/* no protection on below fields, but it's harmless */
if (last_route->lr_seq - route->lr_seq < 0)
last_route = route;
- rc = lnet_compare_routes(route, best_route);
+ rc = lnet_compare_routes(route, best_route, &best_gw_ni);
if (rc < 0)
continue;
@@ -1222,6 +1356,7 @@ void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
}
*prev_route = last_route;
+ *gwni = best_gw_ni;
return best_route;
}
@@ -1507,123 +1642,6 @@ void lnet_usr_translate_stats(struct lnet_ioctl_element_msg_stats *msg_stats,
return rc;
}
-static struct lnet_peer_ni *
-lnet_select_peer_ni(struct lnet_send_data *sd, struct lnet_peer *peer,
- struct lnet_peer_net *peer_net)
-{
- /*
- * Look at the peer NIs for the destination peer that connect
- * to the chosen net. If a peer_ni is preferred when using the
- * best_ni to communicate, we use that one. If there is no
- * preferred peer_ni, or there are multiple preferred peer_ni,
- * the available transmit credits are used. If the transmit
- * credits are equal, we round-robin over the peer_ni.
- */
- struct lnet_peer_ni *lpni = NULL;
- struct lnet_peer_ni *best_lpni = NULL;
- struct lnet_ni *best_ni = sd->sd_best_ni;
- lnet_nid_t dst_nid = sd->sd_dst_nid;
- int best_lpni_credits = INT_MIN;
- bool preferred = false;
- bool ni_is_pref;
- int best_lpni_healthv = 0;
- int lpni_healthv;
-
- while ((lpni = lnet_get_next_peer_ni_locked(peer, peer_net, lpni))) {
- /* if the best_ni we've chosen aleady has this lpni
- * preferred, then let's use it
- */
- ni_is_pref = lnet_peer_is_pref_nid_locked(lpni,
- best_ni->ni_nid);
-
- lpni_healthv = atomic_read(&lpni->lpni_healthv);
-
- CDEBUG(D_NET, "%s ni_is_pref = %d\n",
- libcfs_nid2str(best_ni->ni_nid), ni_is_pref);
-
- if (best_lpni)
- CDEBUG(D_NET, "%s c:[%d, %d], s:[%d, %d]\n",
- libcfs_nid2str(lpni->lpni_nid),
- lpni->lpni_txcredits, best_lpni_credits,
- lpni->lpni_seq, best_lpni->lpni_seq);
-
- /* pick the healthiest peer ni */
- if (lpni_healthv < best_lpni_healthv) {
- continue;
- } else if (lpni_healthv > best_lpni_healthv) {
- best_lpni_healthv = lpni_healthv;
- /* if this is a preferred peer use it */
- } else if (!preferred && ni_is_pref) {
- preferred = true;
- } else if (preferred && !ni_is_pref) {
- /*
- * this is not the preferred peer so let's ignore
- * it.
- */
- continue;
- } else if (lpni->lpni_txcredits < best_lpni_credits) {
- /*
- * We already have a peer that has more credits
- * available than this one. No need to consider
- * this peer further.
- */
- continue;
- } else if (lpni->lpni_txcredits == best_lpni_credits) {
- /*
- * The best peer found so far and the current peer
- * have the same number of available credits let's
- * make sure to select between them using Round
- * Robin
- */
- if (best_lpni) {
- if (best_lpni->lpni_seq <= lpni->lpni_seq)
- continue;
- }
- }
-
- best_lpni = lpni;
- best_lpni_credits = lpni->lpni_txcredits;
- }
-
- /* if we still can't find a peer ni then we can't reach it */
- if (!best_lpni) {
- u32 net_id = peer_net ? peer_net->lpn_net_id :
- LNET_NIDNET(dst_nid);
-
- CDEBUG(D_NET, "no peer_ni found on peer net %s\n",
- libcfs_net2str(net_id));
- return NULL;
- }
-
- CDEBUG(D_NET, "sd_best_lpni = %s\n",
- libcfs_nid2str(best_lpni->lpni_nid));
-
- return best_lpni;
-}
-
-/* Prerequisite: the best_ni should already be set in the sd
- */
-static inline struct lnet_peer_ni *
-lnet_find_best_lpni_on_net(struct lnet_send_data *sd, struct lnet_peer *peer,
- u32 net_id)
-{
- struct lnet_peer_net *peer_net;
-
- /* The gateway is Multi-Rail capable so now we must select the
- * proper peer_ni
- */
- peer_net = lnet_peer_get_net_locked(peer, net_id);
-
- if (!peer_net) {
- CERROR("gateway peer %s has no NI on net %s\n",
- libcfs_nid2str(peer->lp_primary_nid),
- libcfs_net2str(net_id));
- return NULL;
- }
-
- return lnet_select_peer_ni(sd, peer, peer_net);
-}
-
static inline void
lnet_set_non_mr_pref_nid(struct lnet_send_data *sd)
{
@@ -1791,29 +1809,34 @@ struct lnet_ni *
lnet_nid_t src_nid = sd->sd_src_nid;
best_route = lnet_find_route_locked(NULL, LNET_NIDNET(dst_nid),
- sd->sd_rtr_nid, &last_route);
+ sd->sd_rtr_nid, &last_route,
+ &lpni);
if (!best_route) {
CERROR("no route to %s from %s\n",
libcfs_nid2str(dst_nid), libcfs_nid2str(src_nid));
return -EHOSTUNREACH;
}
+ if (!lpni) {
+ 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;
- *gw_peer = gw;
+ LASSERT(gw == lpni->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
* completed
*/
-#if 0
- /* TODO: disable discovey for now */
if (lnet_msg_discovery(sd->sd_msg) &&
- !lnet_peer_is_uptodate(*gw_peer)) {
+ !lnet_peer_is_uptodate(gw)) {
sd->sd_msg->msg_src_nid_param = sd->sd_src_nid;
- return lnet_initiate_peer_discovery(gw, sd->sd_msg,
+ return lnet_initiate_peer_discovery(lpni, sd->sd_msg,
sd->sd_rtr_nid, sd->sd_cpt);
}
-#endif
if (!sd->sd_best_ni) {
struct lnet_peer_net *lpeer;
@@ -1830,42 +1853,8 @@ struct lnet_ni *
return -EFAULT;
}
- /* if gw is MR let's find its best peer_ni
- */
- if (lnet_peer_is_multi_rail(gw)) {
- lpni = lnet_find_best_lpni_on_net(sd, gw,
- sd->sd_best_ni->ni_net->net_id);
- /* We've already verified that the gw has an NI on that
- * desired net, but we're not finding it. Something is
- * wrong.
- */
- if (!lpni) {
- CERROR("Internal Error. Route expected to %s from %s\n",
- libcfs_nid2str(dst_nid),
- libcfs_nid2str(src_nid));
- return -EFAULT;
- }
- } else {
- struct lnet_peer_net *lpn;
-
- lpn = lnet_peer_get_net_locked(gw, best_route->lr_lnet);
- if (!lpn) {
- CERROR("Internal Error. Route expected to %s from %s\n",
- libcfs_nid2str(dst_nid),
- libcfs_nid2str(src_nid));
- return -EFAULT;
- }
- lpni = list_entry(lpn->lpn_peer_nis.next, struct lnet_peer_ni,
- lpni_peer_nis);
- if (!lpni) {
- CERROR("Internal Error. Route expected to %s from %s\n",
- libcfs_nid2str(dst_nid),
- libcfs_nid2str(src_nid));
- return -EFAULT;
- }
- }
-
*gw_lpni = lpni;
+ *gw_peer = gw;
/* increment the route sequence number since now we're sure we're
* going to use it
--
1.8.3.1
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