Commit 0cc1f315 authored by David S. Miller's avatar David S. Miller

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: default avatarDavid S. Miller <davem@davemloft.net>
parents 2c896fb0 e0a05ebe
......@@ -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,
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
......
......@@ -56,7 +56,7 @@ 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,
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[]);
......
......@@ -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
*/
......@@ -237,7 +242,7 @@ 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,
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);
......@@ -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,
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,
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)
......
......@@ -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
......@@ -138,7 +138,7 @@ 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,
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);
......
......@@ -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
*/
......
......@@ -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);
......
/*
* 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.
*
......@@ -46,10 +46,13 @@
*/
enum {
TIPC_BCAST_SYNCH = (1 << 1),
TIPC_BLOCK_FLOWCTL = (2 << 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);
......
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