session: reschedule asap when snd space constrained
Type: feature
Improves fairness for sessions that are snd space or pacer constrained.
Change-Id: Ida5f523090f1dcbfb17bf5116bc7917747ac8593
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index f738f39..9fe35b1 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -221,6 +221,14 @@
pool_elt_at_index (wrk->event_elts, wrk->old_head));
}
+static inline void
+session_evt_add_head_old (session_worker_t * wrk, session_evt_elt_t * elt)
+{
+ clib_llist_add (wrk->event_elts, evt_list, elt,
+ pool_elt_at_index (wrk->event_elts, wrk->old_head));
+}
+
+
static inline u32
session_evt_ctrl_data_alloc (session_worker_t * wrk)
{
diff --git a/src/vnet/session/session_node.c b/src/vnet/session/session_node.c
index b4b384f..3bfc80e 100644
--- a/src/vnet/session/session_node.c
+++ b/src/vnet/session/session_node.c
@@ -865,14 +865,22 @@
}
ctx->snd_mss = ctx->transport_vft->send_mss (ctx->tc);
+ if (PREDICT_FALSE (ctx->snd_mss == 0))
+ {
+ session_evt_add_old (wrk, elt);
+ return SESSION_TX_NO_DATA;
+ }
+
ctx->snd_space = transport_connection_snd_space (ctx->tc,
vm->clib_time.
last_cpu_time,
ctx->snd_mss);
- if (ctx->snd_space == 0 || ctx->snd_mss == 0)
+ /* This flow queue is "empty" so it should be re-evaluated before
+ * the ones that have data to send. */
+ if (ctx->snd_space == 0)
{
- session_evt_add_old (wrk, elt);
+ session_evt_add_head_old (wrk, elt);
return SESSION_TX_NO_DATA;
}
@@ -898,7 +906,7 @@
{
if (n_bufs)
vlib_buffer_free (vm, wrk->tx_buffers, n_bufs);
- session_evt_add_old (wrk, elt);
+ session_evt_add_head_old (wrk, elt);
vlib_node_increment_counter (wrk->vm, node->node_index,
SESSION_QUEUE_ERROR_NO_BUFFER, 1);
return SESSION_TX_NO_BUFFERS;
@@ -1321,19 +1329,24 @@
if (old_ti != wrk->old_head)
{
+ clib_llist_index_t ei, next_ei;
+
old_he = pool_elt_at_index (wrk->event_elts, wrk->old_head);
+ ei = clib_llist_next_index (old_he, evt_list);
+
while (n_tx_packets < VLIB_FRAME_SIZE)
{
- clib_llist_index_t ei;
+ elt = pool_elt_at_index (wrk->event_elts, ei);
+ next_ei = clib_llist_next_index (elt, evt_list);
+ clib_llist_remove (wrk->event_elts, evt_list, elt);
- clib_llist_pop_first (wrk->event_elts, evt_list, elt, old_he);
- ei = clib_llist_entry_index (wrk->event_elts, elt);
session_event_dispatch_io (wrk, node, elt, thread_index,
&n_tx_packets);
- old_he = pool_elt_at_index (wrk->event_elts, wrk->old_head);
if (ei == old_ti)
break;
+
+ ei = next_ei;
};
}