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Make the loss / delay sim available as an output feature

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Add binary api and debug cli support.

Rewrite for speed: enqueue vlib_buffer_t's to the wheel, instead of
memcpy'ing data. Quad-loop the output feature / x-connect (interior)
node. Prefetch wheel entries in the input node.

Save packet-generator-based unit-test setup in extras/nsim.

Simple config example:

set nsim delay 20 ms bandwidth 1 gbit packet-size 1024
nsim output-feature enable-disable GigabitEthernet3/0/0

Change-Id: I852a32d4eb596e7e2aa1d9b30bf3b53525e39fd1
Signed-off-by: Dave Barach <dave@barachs.net>c
This commit is contained in:
Dave Barach
2019-04-03 11:20:06 -04:00
committed by Florin Coras
parent 10dc2eabd6
commit 7c91007e1e
7 changed files with 654 additions and 149 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/plugins/nsim/nsim_input.c
+35 -81
View File
@@ -24,7 +24,7 @@
typedef struct
{
f64 expired;
u32 tx_sw_if_index;
u32 next_index;
} nsim_tx_trace_t;
#ifndef CLIB_MARCH_VARIANT
@@ -36,22 +36,20 @@ format_nsim_tx_trace (u8 * s, va_list * args)
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
nsim_tx_trace_t *t = va_arg (*args, nsim_tx_trace_t *);
s = format (s, "NSIM: tx at %.6f sw_if_index %d",
t->expired, t->tx_sw_if_index);
s = format (s, "NSIM: tx at %.6f next_index %d", t->expired, t->next_index);
return s;
}
#endif /* CLIB_MARCH_VARIANT */
#define foreach_nsim_tx_error \
_(TX, "Packets transmitted") \
_(DROPPED, "No buffer drops")
#define foreach_nsim_tx_error \
_(TRANSMITTED, "Packets transmitted")
typedef enum
{
#define _(sym,str) NSIM_TX_ERROR_##sym,
foreach_nsim_tx_error
#undef _
NSIM_N_ERROR,
NSIM_TX_N_ERROR,
} nsim_tx_error_t;
#ifndef CLIB_MARCH_VARIANT
@@ -74,12 +72,9 @@ nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
{
nsim_main_t *nsm = &nsim_main;
u32 my_thread_index = vm->thread_index;
u32 *my_buffer_cache = nsm->buffer_indices_by_thread[my_thread_index];
nsim_wheel_t *wp = nsm->wheel_by_thread[my_thread_index];
u32 n_trace = vlib_get_trace_count (vm, node);
f64 now = vlib_time_now (vm);
uword n_rx_packets = 0;
vlib_buffer_t *b0;
uword n_tx_packets = 0;
u32 bi0, next0;
u32 *to_next;
u32 next_index;
@@ -93,85 +88,30 @@ nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
/* First entry on the wheel isn't expired? */
ep = wp->entries + wp->head;
if (ep->tx_time > now)
return n_rx_packets;
return n_tx_packets;
/*
* We use per-thread buffer caches, so we need the freelist to
* initialize them...
*/
next_index = node->cached_next_index;
while (wp->cursize)
/* Be aware: this is not the usual coding pattern */
while (wp->cursize && ep->tx_time <= now)
{
/* Be aware: this is not the usual coding pattern */
vlib_buffer_t *b0;
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_to_next > 0 && ep->tx_time <= now)
while (n_left_to_next > 0)
{
/* Out of local buffer cache? */
if (PREDICT_FALSE (_vec_len (my_buffer_cache) == 0))
{
u32 n =
vlib_buffer_alloc (vm, my_buffer_cache, VLIB_FRAME_SIZE);
_vec_len (my_buffer_cache) = n;
/* Ugh, drop the rest of the expired entries */
if (n == 0)
{
u32 drops = 0;
while (ep->tx_time <= now && wp->cursize)
{
wp->head++;
if (wp->head == wp->wheel_size)
wp->head = 0;
ep = wp->entries + wp->head;
wp->cursize--;
drops++;
}
/* Count the drops */
vlib_node_increment_counter (vm, node->node_index,
NSIM_TX_ERROR_DROPPED, drops);
/* Ship any pkts we already processed */
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
return n_rx_packets + drops;
}
}
/* Allocate a buffer */
bi0 = my_buffer_cache[_vec_len (my_buffer_cache) - 1];
_vec_len (my_buffer_cache) -= 1;
/* prefetch one line / 2 entries ahead */
if ((((uword) ep) & (CLIB_CACHE_LINE_BYTES - 1)) == 0)
CLIB_PREFETCH ((ep + 2), CLIB_CACHE_LINE_BYTES, LOAD);
/* Pick up buffer from the wheel */
bi0 = ep->buffer_index;
to_next[0] = bi0;
to_next += 1;
n_left_to_next -= 1;
b0 = vlib_get_buffer (vm, bi0);
/* Initialize the buffer */
b0->current_data = 0;
b0->current_length = ep->current_length;
VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
if (PREDICT_FALSE (n_trace))
{
nsim_tx_trace_t *t0;
vlib_trace_buffer (vm, node, next_index, b0,
0 /* follow_chain */ );
t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
t0->expired = ep->tx_time;
t0->tx_sw_if_index = ep->tx_sw_if_index;
}
/* Copy data from the ring */
clib_memcpy_fast (b0->data, ep->data, ep->current_length);
b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
vnet_buffer (b0)->sw_if_index[VLIB_TX] = ep->tx_sw_if_index;
vnet_buffer (b0)->sw_if_index[VLIB_RX] =
(ep->tx_sw_if_index == nsm->sw_if_index0) ? nsm->sw_if_index1 :
nsm->sw_if_index0;
next0 = (ep->tx_sw_if_index == nsm->sw_if_index0) ?
nsm->output_next_index0 : nsm->output_next_index1;
next0 = ep->output_next_index;
/* verify speculative enqueue, maybe switch current next frame */
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -183,7 +123,19 @@ nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
wp->head = 0;
wp->cursize--;
ep = wp->entries + wp->head;
n_rx_packets++;
n_tx_packets++;
if (is_trace)
{
b0 = vlib_get_buffer (vm, ep->buffer_index);
if (b0->flags & VLIB_BUFFER_IS_TRACED)
{
nsim_tx_trace_t *t =
vlib_add_trace (vm, node, b0, sizeof (*t));
t->expired = now;
t->next_index = next0;
}
}
/* Out of ring entries? */
if (PREDICT_FALSE (wp->cursize == 0))
@@ -196,7 +148,9 @@ nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
if (ep->tx_time > now)
break;
}
return n_rx_packets;
vlib_node_increment_counter (vm, node->node_index,
NSIM_TX_ERROR_TRANSMITTED, n_tx_packets);
return n_tx_packets;
}
VLIB_NODE_FN (nsim_input_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
@@ -221,7 +175,7 @@ VLIB_REGISTER_NODE (nsim_input_node) =
.format_trace = format_nsim_tx_trace,
.n_errors = NSIM_N_ERROR,
.n_errors = NSIM_TX_N_ERROR,
.error_strings = nsim_tx_error_strings,
};
#endif /* CLIB_MARCH_VARIANT */