X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=drivers%2Fnet%2Fmemif%2Frte_eth_memif.c;h=a19c0f3e6b33f4d4361f92ac4be071ac7c501b6e;hb=b805cd8187b927b7c691beec7c58d2c83a1589f3;hp=b6da9a8b40460a92cab59c95aa415a0eb232f05d;hpb=0a77baed7b4a6208cd386a6bb746cc8d5042aa78;p=dpdk.git

diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c
index b6da9a8b40..a19c0f3e6b 100644
--- a/drivers/net/memif/rte_eth_memif.c
+++ b/drivers/net/memif/rte_eth_memif.c
@@ -253,7 +253,12 @@ memif_free_stored_mbufs(struct pmd_process_private *proc_private, struct memif_q
 	memif_ring_t *ring = memif_get_ring_from_queue(proc_private, mq);
 
 	/* FIXME: improve performance */
-	while (mq->last_tail != ring->tail) {
+	/* The ring->tail acts as a guard variable between Tx and Rx
+	 * threads, so using load-acquire pairs with store-release
+	 * to synchronize it between threads.
+	 */
+	while (mq->last_tail != __atomic_load_n(&ring->tail,
+						__ATOMIC_ACQUIRE)) {
 		RTE_MBUF_PREFETCH_TO_FREE(mq->buffers[(mq->last_tail + 1) & mask]);
 		/* Decrement refcnt and free mbuf. (current segment) */
 		rte_mbuf_refcnt_update(mq->buffers[mq->last_tail & mask], -1);
@@ -455,7 +460,11 @@ eth_memif_rx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	mask = ring_size - 1;
 
 	cur_slot = mq->last_tail;
-	last_slot = ring->tail;
+	/* The ring->tail acts as a guard variable between Tx and Rx
+	 * threads, so using load-acquire pairs with store-release
+	 * to synchronize it between threads.
+	 */
+	last_slot = __atomic_load_n(&ring->tail, __ATOMIC_ACQUIRE);
 	if (cur_slot == last_slot)
 		goto refill;
 	n_slots = last_slot - cur_slot;
@@ -501,7 +510,11 @@ next_slot:
 
 /* Supply master with new buffers */
 refill:
-	head = ring->head;
+	/* The ring->head acts as a guard variable between Tx and Rx
+	 * threads, so using load-acquire pairs with store-release
+	 * to synchronize it between threads.
+	 */
+	head = __atomic_load_n(&ring->head, __ATOMIC_ACQUIRE);
 	n_slots = ring_size - head + mq->last_tail;
 
 	if (n_slots < 32)
@@ -526,8 +539,7 @@ refill:
 			(uint8_t *)proc_private->regions[d0->region]->addr;
 	}
 no_free_mbufs:
-	rte_mb();
-	ring->head = head;
+	__atomic_store_n(&ring->head, head, __ATOMIC_RELEASE);
 
 	mq->n_pkts += n_rx_pkts;
 
@@ -723,8 +735,12 @@ eth_memif_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	memif_free_stored_mbufs(proc_private, mq);
 
 	/* ring type always MEMIF_RING_S2M */
-	slot = ring->head;
-	n_free = ring_size - ring->head + mq->last_tail;
+	/* The ring->head acts as a guard variable between Tx and Rx
+	 * threads, so using load-acquire pairs with store-release
+	 * to synchronize it between threads.
+	 */
+	slot = __atomic_load_n(&ring->head, __ATOMIC_ACQUIRE);
+	n_free = ring_size - slot + mq->last_tail;
 
 	int used_slots;
 
@@ -778,12 +794,11 @@ eth_memif_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 	}
 
 no_free_slots:
-	rte_mb();
 	/* update ring pointers */
 	if (type == MEMIF_RING_S2M)
-		ring->head = slot;
+		__atomic_store_n(&ring->head, slot, __ATOMIC_RELEASE);
 	else
-		ring->tail = slot;
+		__atomic_store_n(&ring->tail, slot, __ATOMIC_RELEASE);
 
 	/* Send interrupt, if enabled. */
 	if ((ring->flags & MEMIF_RING_FLAG_MASK_INT) == 0) {
@@ -1806,11 +1821,4 @@ RTE_PMD_REGISTER_PARAM_STRING(net_memif,
 			      ETH_MEMIF_ZC_ARG "=yes|no"
 			      ETH_MEMIF_SECRET_ARG "=<string>");
 
-int memif_logtype;
-
-RTE_INIT(memif_init_log)
-{
-	memif_logtype = rte_log_register("pmd.net.memif");
-	if (memif_logtype >= 0)
-		rte_log_set_level(memif_logtype, RTE_LOG_NOTICE);
-}
+RTE_LOG_REGISTER(memif_logtype, pmd.net.memif, NOTICE);