diff options
author | David S. Miller <davem@davemloft.net> | 2016-09-02 17:10:25 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-09-02 17:10:25 -0700 |
commit | 0cc1f315287bdcc5e772cde1965c316959f57d67 (patch) | |
tree | 80dd3de19aea9eda8f91f2ec6b4ae0d3ff5a8d4a | |
parent | 2c896fb02e7f65299646f295a007bda043e0f382 (diff) | |
parent | e0a05ebe26c07c4f649a7f5c251a3d4d8bf0402d (diff) |
Merge branch 'tipc-scalable-broadcast-NACK'
Jon Maloy says:
====================
tipc: improve broadcast NACK mechanism
The broadcast protocol has turned out to not scale well beyond 70-80
nodes, while it is now possible to build TIPC clusters of at least ten
times that size. This commit series improves the NACK/retransmission
mechanism of the broadcast protocol to make is at scalable as the rest
of TIPC.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | net/tipc/bcast.c | 8 | ||||
-rw-r--r-- | net/tipc/bcast.h | 4 | ||||
-rw-r--r-- | net/tipc/link.c | 131 | ||||
-rw-r--r-- | net/tipc/link.h | 6 | ||||
-rw-r--r-- | net/tipc/msg.h | 10 | ||||
-rw-r--r-- | net/tipc/node.c | 32 | ||||
-rw-r--r-- | net/tipc/node.h | 11 |
7 files changed, 167 insertions, 35 deletions
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index ae469b37d852..753f774cb46f 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -269,18 +269,19 @@ void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked) * * RCU is locked, no other locks set */ -void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, - struct tipc_msg *hdr) +int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, + struct tipc_msg *hdr) { struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq; struct sk_buff_head xmitq; + int rc = 0; __skb_queue_head_init(&xmitq); tipc_bcast_lock(net); if (msg_type(hdr) == STATE_MSG) { tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq); - tipc_link_bc_sync_rcv(l, hdr, &xmitq); + rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq); } else { tipc_link_bc_init_rcv(l, hdr); } @@ -291,6 +292,7 @@ void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, /* Any socket wakeup messages ? */ if (!skb_queue_empty(inputq)) tipc_sk_rcv(net, inputq); + return rc; } /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer diff --git a/net/tipc/bcast.h b/net/tipc/bcast.h index d5e79b3767fd..5ffe34472ccd 100644 --- a/net/tipc/bcast.h +++ b/net/tipc/bcast.h @@ -56,8 +56,8 @@ int tipc_bcast_get_mtu(struct net *net); int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list); int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb); void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked); -void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, - struct tipc_msg *hdr); +int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, + struct tipc_msg *hdr); int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg); int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[]); int tipc_bclink_reset_stats(struct net *net); diff --git a/net/tipc/link.c b/net/tipc/link.c index 2c6e1b9e024b..b36e16cdc945 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -181,7 +181,10 @@ struct tipc_link { u16 acked; struct tipc_link *bc_rcvlink; struct tipc_link *bc_sndlink; - int nack_state; + unsigned long prev_retr; + u16 prev_from; + u16 prev_to; + u8 nack_state; bool bc_peer_is_up; /* Statistics */ @@ -202,6 +205,8 @@ enum { BC_NACK_SND_SUPPRESS, }; +#define TIPC_BC_RETR_LIMIT 10 /* [ms] */ + /* * Interval between NACKs when packets arrive out of order */ @@ -237,8 +242,8 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, u16 rcvgap, int tolerance, int priority, struct sk_buff_head *xmitq); static void link_print(struct tipc_link *l, const char *str); -static void tipc_link_build_nack_msg(struct tipc_link *l, - struct sk_buff_head *xmitq); +static int tipc_link_build_nack_msg(struct tipc_link *l, + struct sk_buff_head *xmitq); static void tipc_link_build_bc_init_msg(struct tipc_link *l, struct sk_buff_head *xmitq); static bool tipc_link_release_pkts(struct tipc_link *l, u16 to); @@ -367,6 +372,18 @@ int tipc_link_bc_peers(struct tipc_link *l) return l->ackers; } +u16 link_bc_rcv_gap(struct tipc_link *l) +{ + struct sk_buff *skb = skb_peek(&l->deferdq); + u16 gap = 0; + + if (more(l->snd_nxt, l->rcv_nxt)) + gap = l->snd_nxt - l->rcv_nxt; + if (skb) + gap = buf_seqno(skb) - l->rcv_nxt; + return gap; +} + void tipc_link_set_mtu(struct tipc_link *l, int mtu) { l->mtu = mtu; @@ -1135,7 +1152,10 @@ int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq) if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf) return 0; l->rcv_unacked = 0; - return TIPC_LINK_SND_BC_ACK; + + /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */ + l->snd_nxt = l->rcv_nxt; + return TIPC_LINK_SND_STATE; } /* Unicast ACK */ @@ -1164,17 +1184,26 @@ void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq) } /* tipc_link_build_nack_msg: prepare link nack message for transmission + * Note that sending of broadcast NACK is coordinated among nodes, to + * reduce the risk of NACK storms towards the sender */ -static void tipc_link_build_nack_msg(struct tipc_link *l, - struct sk_buff_head *xmitq) +static int tipc_link_build_nack_msg(struct tipc_link *l, + struct sk_buff_head *xmitq) { u32 def_cnt = ++l->stats.deferred_recv; + int match1, match2; - if (link_is_bc_rcvlink(l)) - return; + if (link_is_bc_rcvlink(l)) { + match1 = def_cnt & 0xf; + match2 = tipc_own_addr(l->net) & 0xf; + if (match1 == match2) + return TIPC_LINK_SND_STATE; + return 0; + } if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV)) tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq); + return 0; } /* tipc_link_rcv - process TIPC packets/messages arriving from off-node @@ -1225,7 +1254,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, /* Defer delivery if sequence gap */ if (unlikely(seqno != rcv_nxt)) { __tipc_skb_queue_sorted(defq, seqno, skb); - tipc_link_build_nack_msg(l, xmitq); + rc |= tipc_link_build_nack_msg(l, xmitq); break; } @@ -1236,7 +1265,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, rc |= tipc_link_input(l, skb, l->inputq); if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) rc |= tipc_link_build_state_msg(l, xmitq); - if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK)) + if (unlikely(rc & ~TIPC_LINK_SND_STATE)) break; } while ((skb = __skb_dequeue(defq))); @@ -1250,10 +1279,11 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, u16 rcvgap, int tolerance, int priority, struct sk_buff_head *xmitq) { + struct tipc_link *bcl = l->bc_rcvlink; struct sk_buff *skb; struct tipc_msg *hdr; struct sk_buff_head *dfq = &l->deferdq; - bool node_up = link_is_up(l->bc_rcvlink); + bool node_up = link_is_up(bcl); struct tipc_mon_state *mstate = &l->mon_state; int dlen = 0; void *data; @@ -1281,7 +1311,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, msg_set_net_plane(hdr, l->net_plane); msg_set_next_sent(hdr, l->snd_nxt); msg_set_ack(hdr, l->rcv_nxt - 1); - msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1); + msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1); msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1); msg_set_link_tolerance(hdr, tolerance); msg_set_linkprio(hdr, priority); @@ -1291,6 +1321,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, if (mtyp == STATE_MSG) { msg_set_seq_gap(hdr, rcvgap); + msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl)); msg_set_probe(hdr, probe); tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id); msg_set_size(hdr, INT_H_SIZE + dlen); @@ -1573,51 +1604,107 @@ void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr) l->rcv_nxt = peers_snd_nxt; } +/* link_bc_retr eval()- check if the indicated range can be retransmitted now + * - Adjust permitted range if there is overlap with previous retransmission + */ +static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to) +{ + unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr); + + if (less(*to, *from)) + return false; + + /* New retransmission request */ + if ((elapsed > TIPC_BC_RETR_LIMIT) || + less(*to, l->prev_from) || more(*from, l->prev_to)) { + l->prev_from = *from; + l->prev_to = *to; + l->prev_retr = jiffies; + return true; + } + + /* Inside range of previous retransmit */ + if (!less(*from, l->prev_from) && !more(*to, l->prev_to)) + return false; + + /* Fully or partially outside previous range => exclude overlap */ + if (less(*from, l->prev_from)) { + *to = l->prev_from - 1; + l->prev_from = *from; + } + if (more(*to, l->prev_to)) { + *from = l->prev_to + 1; + l->prev_to = *to; + } + l->prev_retr = jiffies; + return true; +} + /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state */ -void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, - struct sk_buff_head *xmitq) +int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, + struct sk_buff_head *xmitq) { + struct tipc_link *snd_l = l->bc_sndlink; u16 peers_snd_nxt = msg_bc_snd_nxt(hdr); + u16 from = msg_bcast_ack(hdr) + 1; + u16 to = from + msg_bc_gap(hdr) - 1; + int rc = 0; if (!link_is_up(l)) - return; + return rc; if (!msg_peer_node_is_up(hdr)) - return; + return rc; /* Open when peer ackowledges our bcast init msg (pkt #1) */ if (msg_ack(hdr)) l->bc_peer_is_up = true; if (!l->bc_peer_is_up) - return; + return rc; + + l->stats.recv_nacks++; /* Ignore if peers_snd_nxt goes beyond receive window */ if (more(peers_snd_nxt, l->rcv_nxt + l->window)) - return; + return rc; + + if (link_bc_retr_eval(snd_l, &from, &to)) + rc = tipc_link_retrans(snd_l, from, to, xmitq); + + l->snd_nxt = peers_snd_nxt; + if (link_bc_rcv_gap(l)) + rc |= TIPC_LINK_SND_STATE; + + /* Return now if sender supports nack via STATE messages */ + if (l->peer_caps & TIPC_BCAST_STATE_NACK) + return rc; + + /* Otherwise, be backwards compatible */ if (!more(peers_snd_nxt, l->rcv_nxt)) { l->nack_state = BC_NACK_SND_CONDITIONAL; - return; + return 0; } /* Don't NACK if one was recently sent or peeked */ if (l->nack_state == BC_NACK_SND_SUPPRESS) { l->nack_state = BC_NACK_SND_UNCONDITIONAL; - return; + return 0; } /* Conditionally delay NACK sending until next synch rcv */ if (l->nack_state == BC_NACK_SND_CONDITIONAL) { l->nack_state = BC_NACK_SND_UNCONDITIONAL; if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN) - return; + return 0; } /* Send NACK now but suppress next one */ tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq); l->nack_state = BC_NACK_SND_SUPPRESS; + return 0; } void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked, @@ -1654,6 +1741,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked, } /* tipc_link_bc_nack_rcv(): receive broadcast nack message + * This function is here for backwards compatibility, since + * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5. */ int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq) diff --git a/net/tipc/link.h b/net/tipc/link.h index d7e9d42fcb2d..d1bd1787a768 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -63,7 +63,7 @@ enum { enum { TIPC_LINK_UP_EVT = 1, TIPC_LINK_DOWN_EVT = (1 << 1), - TIPC_LINK_SND_BC_ACK = (1 << 2) + TIPC_LINK_SND_STATE = (1 << 2) }; /* Starting value for maximum packet size negotiation on unicast links @@ -138,8 +138,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked, void tipc_link_build_bc_sync_msg(struct tipc_link *l, struct sk_buff_head *xmitq); void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr); -void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, - struct sk_buff_head *xmitq); +int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, + struct sk_buff_head *xmitq); int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb, struct sk_buff_head *xmitq); #endif diff --git a/net/tipc/msg.h b/net/tipc/msg.h index 7cf52fb39bee..c3832cdf2278 100644 --- a/net/tipc/msg.h +++ b/net/tipc/msg.h @@ -719,6 +719,16 @@ static inline char *msg_media_addr(struct tipc_msg *m) return (char *)&m->hdr[TIPC_MEDIA_INFO_OFFSET]; } +static inline u32 msg_bc_gap(struct tipc_msg *m) +{ + return msg_bits(m, 8, 0, 0x3ff); +} + +static inline void msg_set_bc_gap(struct tipc_msg *m, u32 n) +{ + msg_set_bits(m, 8, 0, 0x3ff, n); +} + /* * Word 9 */ diff --git a/net/tipc/node.c b/net/tipc/node.c index 7e8b75fd1a02..7ef14e2d2356 100644 --- a/net/tipc/node.c +++ b/net/tipc/node.c @@ -1262,6 +1262,34 @@ void tipc_node_broadcast(struct net *net, struct sk_buff *skb) kfree_skb(skb); } +static void tipc_node_bc_sync_rcv(struct tipc_node *n, struct tipc_msg *hdr, + int bearer_id, struct sk_buff_head *xmitq) +{ + struct tipc_link *ucl; + int rc; + + rc = tipc_bcast_sync_rcv(n->net, n->bc_entry.link, hdr); + + if (rc & TIPC_LINK_DOWN_EVT) { + tipc_bearer_reset_all(n->net); + return; + } + + if (!(rc & TIPC_LINK_SND_STATE)) + return; + + /* If probe message, a STATE response will be sent anyway */ + if (msg_probe(hdr)) + return; + + /* Produce a STATE message carrying broadcast NACK */ + tipc_node_read_lock(n); + ucl = n->links[bearer_id].link; + if (ucl) + tipc_link_build_state_msg(ucl, xmitq); + tipc_node_read_unlock(n); +} + /** * tipc_node_bc_rcv - process TIPC broadcast packet arriving from off-node * @net: the applicable net namespace @@ -1298,7 +1326,7 @@ static void tipc_node_bc_rcv(struct net *net, struct sk_buff *skb, int bearer_id rc = tipc_bcast_rcv(net, be->link, skb); /* Broadcast ACKs are sent on a unicast link */ - if (rc & TIPC_LINK_SND_BC_ACK) { + if (rc & TIPC_LINK_SND_STATE) { tipc_node_read_lock(n); tipc_link_build_state_msg(le->link, &xmitq); tipc_node_read_unlock(n); @@ -1505,7 +1533,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b) /* Ensure broadcast reception is in synch with peer's send state */ if (unlikely(usr == LINK_PROTOCOL)) - tipc_bcast_sync_rcv(net, n->bc_entry.link, hdr); + tipc_node_bc_sync_rcv(n, hdr, bearer_id, &xmitq); else if (unlikely(tipc_link_acked(n->bc_entry.link) != bc_ack)) tipc_bcast_ack_rcv(net, n->bc_entry.link, bc_ack); diff --git a/net/tipc/node.h b/net/tipc/node.h index 4578b34c7dca..39ef54c1f2ad 100644 --- a/net/tipc/node.h +++ b/net/tipc/node.h @@ -1,7 +1,7 @@ /* * net/tipc/node.h: Include file for TIPC node management routines * - * Copyright (c) 2000-2006, 2014-2015, Ericsson AB + * Copyright (c) 2000-2006, 2014-2016, Ericsson AB * Copyright (c) 2005, 2010-2014, Wind River Systems * All rights reserved. * @@ -45,11 +45,14 @@ /* Optional capabilities supported by this code version */ enum { - TIPC_BCAST_SYNCH = (1 << 1), - TIPC_BLOCK_FLOWCTL = (2 << 1) + TIPC_BCAST_SYNCH = (1 << 1), + TIPC_BCAST_STATE_NACK = (1 << 2), + TIPC_BLOCK_FLOWCTL = (1 << 3) }; -#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | TIPC_BLOCK_FLOWCTL) +#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \ + TIPC_BCAST_STATE_NACK | \ + TIPC_BLOCK_FLOWCTL) #define INVALID_BEARER_ID -1 void tipc_node_stop(struct net *net); |