packet_ordering example works in two modes (--disable-reorder):
- When reorder is enabled: rx_thread - N*worker_thread - send_thread
- When reorder is disabled: rx_thread - N*worker_thread - tx_thread
N parallel worker_thread(s) generate out-of-order packets.
When reorder is enabled, send_thread uses sequence number generated in
rx_thread (Line 459) to enforce packet ordering. Otherwise rx_thread just sends
any packet it receives.
rx_thread writes sequence number into a dynamic field, which is only registered
by calling rte_reorder_create() (Line 741) when reorder is enabled. However,
rx_thread marks sequence number onto each packet no matter whether reorder is
enabled, overwriting the leading bytes in packet mbufs when reorder is
disabled, resulting in segfaults when PMD tries to DMA packets.
if (!disable_reorder) {...} is added to fix the bug.
---
examples/packet_ordering/main.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/examples/packet_ordering/main.c b/examples/packet_ordering/main.c
index d2fd6f77e4..7688f541ba 100644
--- a/examples/packet_ordering/main.c
+++ b/examples/packet_ordering/main.c
@@ -455,8 +455,11 @@ rx_thread(struct rte_ring *ring_out)
app_stats.rx.rx_pkts += nb_rx_pkts;
/* mark sequence number */
- for (i = 0; i < nb_rx_pkts; )
- *rte_reorder_seqn(pkts[i++]) = seqn++;
+ if (!disable_reorder) {
+ for (i = 0; i < nb_rx_pkts;) {
+ *rte_reorder_seqn(pkts[i++]) =
seqn++;
+ }
+ }
/* enqueue to rx_to_workers ring */
ret = rte_ring_enqueue_burst(ring_out,
--
2.34.1
