@@ -585,7 +585,13 @@ eth_memif_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
mask = ring_size - 1;
if (type == MEMIF_RING_S2M) {
- slot = __atomic_load_n(&ring->head, __ATOMIC_ACQUIRE);
+ /* For S2M queues ring->head is updated by the sender and
+ * this function is called in the context of sending thread.
+ * The loads in the sender do not need to synchronize with
+ * its own stores. Hence, the following load can be a
+ * relaxed load.
+ */
+ slot = __atomic_load_n(&ring->head, __ATOMIC_RELAXED);
n_free = ring_size - slot +
__atomic_load_n(&ring->tail, __ATOMIC_ACQUIRE);
} else {
For S2M rings, ring->head is updated by the sender and eth_memif_tx function is called in the context of sending thread. The loads in the sender do not need to synchronize with its own stores. Fixes: a2aafb9aa651 ("net/memif: optimize with one-way barrier") Cc: phil.yang@arm.com Cc: stable@dpdk.org Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Reviewed-by: Phil Yang <phil.yang@arm.com> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com> --- drivers/net/memif/rte_eth_memif.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 2.17.1