ring/c11: keep deterministic order allowing retry to work

[dpdk.git] / lib / librte_ring / rte_ring_c11_mem.h

diff --git a/lib/librte_ring/rte_ring_c11_mem.h b/lib/librte_ring/rte_ring_c11_mem.h
index 7bc74a4..dc49a99 100644 (file)
--- a/lib/librte_ring/rte_ring_c11_mem.h
+++ b/lib/librte_ring/rte_ring_c11_mem.h
@@ -66,6 +66,9 @@ __rte_ring_move_prod_head(struct rte_ring *r, unsigned int is_sp,
                /* Reset n to the initial burst count */
                n = max;
 
+               /* Ensure the head is read before tail */
+               __atomic_thread_fence(__ATOMIC_ACQUIRE);
+
                /* load-acquire synchronize with store-release of ht->tail
                 * in update_tail.
                 */
@@ -139,6 +142,9 @@ __rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
                /* Restore n as it may change every loop */
                n = max;
 
+               /* Ensure the head is read before tail */
+               __atomic_thread_fence(__ATOMIC_ACQUIRE);
+
                /* this load-acquire synchronize with store-release of ht->tail
                 * in update_tail.
                 */