Improve L2FIB PDR/NDR performance (VPP-963)
1. Limit MAC entry update per l2-learn call to reduce update burst
when wall clock advance to the the next minute so all MAC time
stamps are behind current time needing update.
2. Optimize l2-learn node fast path code sequence.
3. Invalidate cache_key when update MAC entry.
4. Change L2 learn hit counter to L2 learn hit-update counter.
5. Increase L2FIB table memory size to 512MB to fit 4M entries
6. Set MAC learn limit at 4M entries
Change-Id: I3075ee8fb59645a56850126bac2e3e6d341cef4d
Signed-off-by: John Lo <loj@cisco.com>
diff --git a/src/vnet/l2/l2_learn.c b/src/vnet/l2/l2_learn.c
index 623c2de..066bb54 100644
--- a/src/vnet/l2/l2_learn.c
+++ b/src/vnet/l2/l2_learn.c
@@ -78,7 +78,7 @@
_(MAC_MOVE, "L2 mac moves") \
_(MAC_MOVE_VIOLATE, "L2 mac move violations") \
_(LIMIT, "L2 not learned due to limit") \
-_(HIT, "L2 learn hits") \
+_(HIT_UPDATE, "L2 learn hit updates") \
_(FILTER_DROP, "L2 filter mac drops")
typedef enum
@@ -113,7 +113,7 @@
u32 sw_if_index0,
l2fib_entry_key_t * key0,
l2fib_entry_key_t * cached_key,
- u32 * bucket0,
+ u32 * count,
l2fib_entry_result_t * result0, u32 * next0, u8 timestamp)
{
/* Set up the default next node (typically L2FWD) */
@@ -124,15 +124,24 @@
if (PREDICT_TRUE (result0->fields.sw_if_index == sw_if_index0))
{
/* Entry in L2FIB with matching sw_if_index matched - normal fast path */
- counter_base[L2LEARN_ERROR_HIT] += 1;
- int update = !result0->fields.age_not && /* static_mac always age_not */
- (result0->fields.timestamp != timestamp ||
- result0->fields.sn.as_u16 != vnet_buffer (b0)->l2.l2fib_sn);
+ u32 dtime = timestamp - result0->fields.timestamp;
+ u32 dsn = result0->fields.sn.as_u16 - vnet_buffer (b0)->l2.l2fib_sn;
+ u32 check = dtime | dsn;
- if (PREDICT_TRUE (!update))
- return;
- else if (msm->global_learn_count > msm->global_learn_limit)
+ if (PREDICT_TRUE (check == 0))
+ return; /* MAC entry up to date */
+ if (result0->fields.age_not)
+ return; /* Static MAC always age_not */
+ if (msm->global_learn_count > msm->global_learn_limit)
return; /* Above learn limit - do not update */
+
+ /* Limit updates per l2-learn node call to avoid prolonged update burst
+ * as dtime advance over 1 minute mark, unless more than 1 min behind */
+ if ((*count > 2) && (dtime == 1))
+ return;
+
+ counter_base[L2LEARN_ERROR_HIT_UPDATE] += 1;
+ *count += 1;
}
else if (result0->raw == ~0)
{
@@ -160,7 +169,6 @@
result0->raw = 0; /* clear all fields */
result0->fields.sw_if_index = sw_if_index0;
result0->fields.lrn_evt = (msm->client_pid != 0);
- cached_key->raw = ~0; /* invalidate the cache */
}
else
{
@@ -207,6 +215,9 @@
kv.key = key0->raw;
kv.value = result0->raw;
BV (clib_bihash_add_del) (msm->mac_table, &kv, 1 /* is_add */ );
+
+ /* Invalidate the cache */
+ cached_key->raw = ~0;
}
@@ -223,6 +234,7 @@
l2fib_entry_key_t cached_key;
l2fib_entry_result_t cached_result;
u8 timestamp = (u8) (vlib_time_now (vm) / 60);
+ u32 count = 0;
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors; /* number of packets to process */
@@ -358,19 +370,19 @@
l2learn_process (node, msm, &em->counters[node_counter_base_index],
b0, sw_if_index0, &key0, &cached_key,
- &bucket0, &result0, &next0, timestamp);
+ &count, &result0, &next0, timestamp);
l2learn_process (node, msm, &em->counters[node_counter_base_index],
b1, sw_if_index1, &key1, &cached_key,
- &bucket1, &result1, &next1, timestamp);
+ &count, &result1, &next1, timestamp);
l2learn_process (node, msm, &em->counters[node_counter_base_index],
b2, sw_if_index2, &key2, &cached_key,
- &bucket2, &result2, &next2, timestamp);
+ &count, &result2, &next2, timestamp);
l2learn_process (node, msm, &em->counters[node_counter_base_index],
b3, sw_if_index3, &key3, &cached_key,
- &bucket3, &result3, &next3, timestamp);
+ &count, &result3, &next3, timestamp);
/* verify speculative enqueues, maybe switch current next frame */
/* if next0==next1==next_index then nothing special needs to be done */
@@ -425,7 +437,7 @@
l2learn_process (node, msm, &em->counters[node_counter_base_index],
b0, sw_if_index0, &key0, &cached_key,
- &bucket0, &result0, &next0, timestamp);
+ &count, &result0, &next0, timestamp);
/* verify speculative enqueue, maybe switch current next frame */
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,