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ip: avoid fib lookup for consecutive pkts having same source IP

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Type: fix
Fixes: be2286b0

This patch does following:

- If terminating frame has consecutive packets with same source IP, this patch
  avoids fib lookup for those packets in ip4-local node. This drops cycle count
  for ip4-local node on both ARM and x86. It being done by enabling dead code in
  else {} case of ip4_local_check_src_x2() and ip4_local_check_src() functions.

- In case all packets in terminating frame have unique source IP (e.g:
  incrementing), ip4-local is costlier by 2 cycles (broadwell)

Change-Id: I472ddc324716cec8bfe601568b8aeb7565f97ab3
Signed-off-by: Nitin Saxena <nsaxena@marvell.com>
(cherry picked from commit 2d18d2ea9f0e3d6c47d365ec135af651b14e8165)
This commit is contained in:
Nitin Saxena
2020-01-04 12:28:42 +05:30
committed by Dave Wallace
parent a4200a6824
commit d07624f149
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
src/vnet/ip/ip4_forward.c
View File

@ -1502,8 +1502,8 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
* vnet_buffer()->ip.adj_index[VLIB_TX] will be set to the index of the
* adjacency for the source address (the remote sender's address)
*/
if (PREDICT_FALSE (last_check->first ||
(last_check->src.as_u32 != ip0->src_address.as_u32)))
if (PREDICT_TRUE (last_check->src.as_u32 != ip0->src_address.as_u32) ||
last_check->first)
{
mtrie0 = &ip4_fib_get (vnet_buffer (b)->ip.fib_index)->mtrie;
leaf0 = ip4_fib_mtrie_lookup_step_one (mtrie0, &ip0->src_address);
@ -1540,6 +1540,7 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
last_check->src.as_u32 = ip0->src_address.as_u32;
last_check->lbi = lbi0;
last_check->error = *error0;
last_check->first = 0;
}
else
{
@ -1547,7 +1548,6 @@ ip4_local_check_src (vlib_buffer_t * b, ip4_header_t * ip0,
vnet_buffer (b)->ip.adj_index[VLIB_TX];
vnet_buffer (b)->ip.adj_index[VLIB_TX] = last_check->lbi;
*error0 = last_check->error;
last_check->first = 0;
}
}
@ -1582,7 +1582,7 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
* vnet_buffer()->ip.adj_index[VLIB_TX] will be set to the index of the
* adjacency for the source address (the remote sender's address)
*/
if (PREDICT_FALSE (not_last_hit))
if (PREDICT_TRUE (not_last_hit))
{
mtrie[0] = &ip4_fib_get (vnet_buffer (b[0])->ip.fib_index)->mtrie;
mtrie[1] = &ip4_fib_get (vnet_buffer (b[1])->ip.fib_index)->mtrie;
@ -1636,6 +1636,7 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
last_check->src.as_u32 = ip[1]->src_address.as_u32;
last_check->lbi = lbi[1];
last_check->error = error[1];
last_check->first = 0;
}
else
{
@ -1649,7 +1650,6 @@ ip4_local_check_src_x2 (vlib_buffer_t ** b, ip4_header_t ** ip,
error[0] = last_check->error;
error[1] = last_check->error;
last_check->first = 0;
}
}