X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=lib%2Flibrte_ring%2Frte_ring.h;h=eb45e41449b33a2e5292ca12c317e161da7cb4ab;hb=99c12dcca65d;hp=943c97cf4a8c664b93d925bd11808c94ceac34b6;hpb=693f715da45c48ec1ec0fe4ba2f3b5ffd11ba53e;p=dpdk.git

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index 943c97cf4a..eb45e41449 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -431,6 +431,11 @@ __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
 	uint32_t mask = r->prod.mask;
 	int ret;
 
+	/* Avoid the unnecessary cmpset operation below, which is also
+	 * potentially harmful when n equals 0. */
+	if (n == 0)
+		return 0;
+
 	/* move prod.head atomically */
 	do {
 		/* Reset n to the initial burst count */
@@ -618,6 +623,11 @@ __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
 	unsigned i, rep = 0;
 	uint32_t mask = r->prod.mask;
 
+	/* Avoid the unnecessary cmpset operation below, which is also
+	 * potentially harmful when n equals 0. */
+	if (n == 0)
+		return 0;
+
 	/* move cons.head atomically */
 	do {
 		/* Restore n as it may change every loop */