ixgbe: fix setup of mbuf initializer template

Add a compiler barrier to make sure all fields covered by
the marker rearm_data are assigned before the read.

Fixes: 0ff3324da2 ("ixgbe: rework vector pmd following mbuf changes")

Signed-off-by: Jean-Mickael Guerin <jean-mickael.guerin@6wind.com>
Acked-by: David Marchand <david.marchand@6wind.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
index 579bc46..c1b5a78 100644 (file)
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
@@ -739,6 +739,9 @@ ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq)
        mb_def.buf_len = rxq->mb_pool->elt_size - sizeof(struct rte_mbuf);
        mb_def.port = rxq->port_id;
        rte_mbuf_refcnt_set(&mb_def, 1);
+
+       /* prevent compiler reordering: rearm_data covers previous fields */
+       rte_compiler_barrier();
        rxq->mbuf_initializer = *((uint64_t *)&mb_def.rearm_data);
        return 0;
 }