tipc: remove the bearer congestion mechanism
Currently at the TIPC bearer layer there is the following congestion
mechanism:
Once sending packets has failed via that bearer, the bearer will be
flagged as being in congested state at once. During bearer congestion,
all packets arriving at link will be queued on the link's outgoing
buffer. When we detect that the state of bearer congestion has
relaxed (e.g. some packets are received from the bearer) we will try
our best to push all packets in the link's outgoing buffer until the
buffer is empty, or until the bearer is congested again.
However, in fact the TIPC bearer never receives any feedback from the
device layer whether a send was successful or not, so it must always
assume it was successful. Therefore, the bearer congestion mechanism
as it exists currently is of no value.
But the bearer blocking state is still useful for us. For example,
when the physical media goes down/up, we need to change the state of
the links bound to the bearer. So the code maintaing the state
information is not removed.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/tipc/link.c b/net/tipc/link.c
index a79c755..0cc6480 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -872,17 +872,12 @@
return link_send_long_buf(l_ptr, buf);
/* Packet can be queued or sent. */
- if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
+ if (likely(!tipc_bearer_blocked(l_ptr->b_ptr) &&
!link_congested(l_ptr))) {
link_add_to_outqueue(l_ptr, buf, msg);
- if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
- l_ptr->unacked_window = 0;
- } else {
- tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
- l_ptr->stats.bearer_congs++;
- l_ptr->next_out = buf;
- }
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
+ l_ptr->unacked_window = 0;
return dsz;
}
/* Congestion: can message be bundled ? */
@@ -891,10 +886,8 @@
/* Try adding message to an existing bundle */
if (l_ptr->next_out &&
- link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
- tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
+ link_bundle_buf(l_ptr, l_ptr->last_out, buf))
return dsz;
- }
/* Try creating a new bundle */
if (size <= max_packet * 2 / 3) {
@@ -917,7 +910,6 @@
if (!l_ptr->next_out)
l_ptr->next_out = buf;
link_add_to_outqueue(l_ptr, buf, msg);
- tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
return dsz;
}
@@ -1006,16 +998,11 @@
if (likely(!link_congested(l_ptr))) {
if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
- if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
+ if (likely(!tipc_bearer_blocked(l_ptr->b_ptr))) {
link_add_to_outqueue(l_ptr, buf, msg);
- if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
- &l_ptr->media_addr))) {
- l_ptr->unacked_window = 0;
- return res;
- }
- tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
- l_ptr->stats.bearer_congs++;
- l_ptr->next_out = buf;
+ tipc_bearer_send(l_ptr->b_ptr, buf,
+ &l_ptr->media_addr);
+ l_ptr->unacked_window = 0;
return res;
}
} else
@@ -1106,7 +1093,7 @@
/* Exit if link (or bearer) is congested */
if (link_congested(l_ptr) ||
- !list_empty(&l_ptr->b_ptr->cong_links)) {
+ tipc_bearer_blocked(l_ptr->b_ptr)) {
res = link_schedule_port(l_ptr,
sender->ref, res);
goto exit;
@@ -1329,15 +1316,11 @@
if (r_q_size && buf) {
msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
- if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
- l_ptr->retransm_queue_head = mod(++r_q_head);
- l_ptr->retransm_queue_size = --r_q_size;
- l_ptr->stats.retransmitted++;
- return 0;
- } else {
- l_ptr->stats.bearer_congs++;
- return PUSH_FAILED;
- }
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
+ l_ptr->retransm_queue_head = mod(++r_q_head);
+ l_ptr->retransm_queue_size = --r_q_size;
+ l_ptr->stats.retransmitted++;
+ return 0;
}
/* Send deferred protocol message, if any: */
@@ -1345,15 +1328,11 @@
if (buf) {
msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
- if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
- l_ptr->unacked_window = 0;
- kfree_skb(buf);
- l_ptr->proto_msg_queue = NULL;
- return 0;
- } else {
- l_ptr->stats.bearer_congs++;
- return PUSH_FAILED;
- }
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
+ l_ptr->unacked_window = 0;
+ kfree_skb(buf);
+ l_ptr->proto_msg_queue = NULL;
+ return 0;
}
/* Send one deferred data message, if send window not full: */
@@ -1366,18 +1345,14 @@
if (mod(next - first) < l_ptr->queue_limit[0]) {
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
- if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
- if (msg_user(msg) == MSG_BUNDLER)
- msg_set_type(msg, CLOSED_MSG);
- l_ptr->next_out = buf->next;
- return 0;
- } else {
- l_ptr->stats.bearer_congs++;
- return PUSH_FAILED;
- }
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
+ if (msg_user(msg) == MSG_BUNDLER)
+ msg_set_type(msg, CLOSED_MSG);
+ l_ptr->next_out = buf->next;
+ return 0;
}
}
- return PUSH_FINISHED;
+ return 1;
}
/*
@@ -1388,15 +1363,12 @@
{
u32 res;
- if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
+ if (tipc_bearer_blocked(l_ptr->b_ptr))
return;
do {
res = tipc_link_push_packet(l_ptr);
} while (!res);
-
- if (res == PUSH_FAILED)
- tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
}
static void link_reset_all(unsigned long addr)
@@ -1481,7 +1453,7 @@
msg = buf_msg(buf);
- if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
+ if (tipc_bearer_blocked(l_ptr->b_ptr)) {
if (l_ptr->retransm_queue_size == 0) {
l_ptr->retransm_queue_head = msg_seqno(msg);
l_ptr->retransm_queue_size = retransmits;
@@ -1491,7 +1463,7 @@
}
return;
} else {
- /* Detect repeated retransmit failures on uncongested bearer */
+ /* Detect repeated retransmit failures on unblocked bearer */
if (l_ptr->last_retransmitted == msg_seqno(msg)) {
if (++l_ptr->stale_count > 100) {
link_retransmit_failure(l_ptr, buf);
@@ -1507,17 +1479,10 @@
msg = buf_msg(buf);
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
- if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
- buf = buf->next;
- retransmits--;
- l_ptr->stats.retransmitted++;
- } else {
- tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
- l_ptr->stats.bearer_congs++;
- l_ptr->retransm_queue_head = buf_seqno(buf);
- l_ptr->retransm_queue_size = retransmits;
- return;
- }
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
+ buf = buf->next;
+ retransmits--;
+ l_ptr->stats.retransmitted++;
}
l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
@@ -1972,21 +1937,13 @@
skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
- /* Defer message if bearer is already congested */
- if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
+ /* Defer message if bearer is already blocked */
+ if (tipc_bearer_blocked(l_ptr->b_ptr)) {
l_ptr->proto_msg_queue = buf;
return;
}
- /* Defer message if attempting to send results in bearer congestion */
- if (!tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
- tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
- l_ptr->proto_msg_queue = buf;
- l_ptr->stats.bearer_congs++;
- return;
- }
-
- /* Discard message if it was sent successfully */
+ tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
l_ptr->unacked_window = 0;
kfree_skb(buf);
}
@@ -2937,8 +2894,8 @@
s->sent_nacks, s->sent_acks, s->retransmitted);
ret += tipc_snprintf(buf + ret, buf_size - ret,
- " Congestion bearer:%u link:%u Send queue"
- " max:%u avg:%u\n", s->bearer_congs, s->link_congs,
+ " Congestion link:%u Send queue"
+ " max:%u avg:%u\n", s->link_congs,
s->max_queue_sz, s->queue_sz_counts ?
(s->accu_queue_sz / s->queue_sz_counts) : 0);