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authorFlorin Coras <fcoras@cisco.com>2020-07-31 13:56:40 -0700
committerFlorin Coras <fcoras@cisco.com>2020-07-31 13:57:24 -0700
commit9811007f5f2c9cdc6219607a2a0e002054a07efd (patch)
tree85e98103188ff6e9e43815c5c91b1c5819299fb4
parente6c3e8f0ee47799c76bdca362c4d75af62aacac3 (diff)
nsim: limit tx burst size and refactor input node
Type: improvement Signed-off-by: Florin Coras <fcoras@cisco.com> Change-Id: Ic93a598051d437a5801d794b678edf6e73d42a47
-rw-r--r--src/plugins/nsim/nsim.h2
-rw-r--r--src/plugins/nsim/nsim_input.c92
2 files changed, 30 insertions, 64 deletions
diff --git a/src/plugins/nsim/nsim.h b/src/plugins/nsim/nsim.h
index 7222a96dcb4..d7d32b9d234 100644
--- a/src/plugins/nsim/nsim.h
+++ b/src/plugins/nsim/nsim.h
@@ -25,6 +25,8 @@
#include <vppinfra/hash.h>
#include <vppinfra/error.h>
+#define NSIM_MAX_TX_BURST 32 /**< max packets in a tx burst */
+
typedef struct
{
f64 tx_time;
diff --git a/src/plugins/nsim/nsim_input.c b/src/plugins/nsim/nsim_input.c
index 3ce89bc9847..6b8bfee135f 100644
--- a/src/plugins/nsim/nsim_input.c
+++ b/src/plugins/nsim/nsim_input.c
@@ -71,15 +71,9 @@ nsim_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
vlib_frame_t * f, int is_trace)
{
nsim_main_t *nsm = &nsim_main;
- u32 my_thread_index = vm->thread_index;
- nsim_wheel_t *wp = nsm->wheel_by_thread[my_thread_index];
- f64 now = vlib_time_now (vm);
- uword n_tx_packets = 0;
- u32 bi0, next0;
- u32 *to_next;
- u32 next_index;
- u32 n_left_to_next;
+ nsim_wheel_t *wp = nsm->wheel_by_thread[vm->thread_index];
nsim_wheel_entry_t *ep;
+ f64 now;
/* Nothing on the scheduler wheel? */
if (wp->cursize == 0)
@@ -87,67 +81,37 @@ 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;
+ now = vlib_time_now (vm);
if (ep->tx_time > now)
- return n_tx_packets;
+ return 0;
- next_index = node->cached_next_index;
+ u32 n_burst = clib_min (wp->cursize, NSIM_MAX_TX_BURST), n_tx_packets = 0;
+ u32 froms[NSIM_MAX_TX_BURST], *from;
+ u16 nexts[NSIM_MAX_TX_BURST], *next;
- /* Be aware: this is not the usual coding pattern */
- while (wp->cursize && ep->tx_time <= now)
+ from = froms;
+ next = nexts;
+ while (n_tx_packets < n_burst && ep->tx_time <= now)
{
- vlib_buffer_t *b0;
-
- vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
-
- while (n_left_to_next > 0)
- {
- /* 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;
-
- next0 = ep->output_next_index;
-
- /* verify speculative enqueue, maybe switch current next frame */
- vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
- to_next, n_left_to_next,
- bi0, next0);
- /* Advance to the next ring entry */
- wp->head++;
- if (wp->head == wp->wheel_size)
- wp->head = 0;
- wp->cursize--;
- ep = wp->entries + wp->head;
- n_tx_packets++;
-
- if (is_trace)
- {
- b0 = vlib_get_buffer (vm, bi0);
- 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))
- break;
- }
-
- vlib_put_next_frame (vm, node, next_index, n_left_to_next);
-
- /* If the current entry hasn't expired, we're done */
- if (ep->tx_time > now)
- break;
+ /* prefetch one line / 2 entries ahead */
+ if ((((uword) ep) & (CLIB_CACHE_LINE_BYTES - 1)) == 0)
+ CLIB_PREFETCH ((ep + 2), CLIB_CACHE_LINE_BYTES, LOAD);
+
+ ep = wp->entries + wp->head;
+ from[0] = ep->buffer_index;
+ next[0] = ep->output_next_index;
+
+ wp->head++;
+ if (wp->head == wp->wheel_size)
+ wp->head = 0;
+
+ from += 1;
+ next += 1;
+ n_tx_packets++;
}
+
+ wp->cursize -= n_tx_packets;
+ vlib_buffer_enqueue_to_next (vm, node, froms, nexts, n_tx_packets);
vlib_node_increment_counter (vm, node->node_index,
NSIM_TX_ERROR_TRANSMITTED, n_tx_packets);
return n_tx_packets;