tipc: Improve accuracy of link transmit queue maximum size statistic

Enhances TIPC's unicast and broadcast link code to update the transmit
queue maximum size counter in a single place, namely the routine that
adds messages to the queue. This ensures that the maximum size statistic
reported for unicast links is completely accurate, rather than being
partially based on statistical sampling.

The changes to link.h are just documenting the roles of the variables.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 0cb773b7ee21..d1818fbc19a3 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -246,9 +246,6 @@ static void link_timeout(struct link *l_ptr)
         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
         l_ptr->stats.queue_sz_counts++;
 
-        if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
-                l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
-
         if (l_ptr->first_out) {
                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
                 u32 length = msg_size(msg);
@@ -824,7 +821,10 @@ static void link_add_to_outqueue(struct link *l_ptr,
                 l_ptr->last_out = buf;
         } else
                 l_ptr->first_out = l_ptr->last_out = buf;
+
         l_ptr->out_queue_size++;
+        if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
+                l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 }
 
 /*
@@ -867,9 +867,6 @@ int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
 
         /* Packet can be queued or sent: */
 
-        if (queue_size > l_ptr->stats.max_queue_sz)
-                l_ptr->stats.max_queue_sz = queue_size;
-
         if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
                    !link_congested(l_ptr))) {
                 link_add_to_outqueue(l_ptr, buf, msg);