X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;ds=sidebyside;f=lib%2Flibrte_ring%2Frte_ring.h;h=af68888fc1e728cfcc500ed9d76bf5ebc84a4e1f;hb=a2348166ea186506d45b61d5073d16ad974e79bb;hp=39bacdd6ae200d2deb4582cfaf0509288dd169d8;hpb=b4bee5f66a72e435da04c7993bbe909846b50618;p=dpdk.git

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index 39bacdd6ae..af68888fc1 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -101,6 +101,8 @@ extern "C" {
 #include <rte_atomic.h>
 #include <rte_branch_prediction.h>
 
+#define RTE_TAILQ_RING_NAME "RTE_RING"
+
 enum rte_ring_queue_behavior {
 	RTE_RING_QUEUE_FIXED = 0, /* Enq/Deq a fixed number of items from a ring */
 	RTE_RING_QUEUE_VARIABLE   /* Enq/Deq as many items a possible from ring */
@@ -127,6 +129,11 @@ struct rte_ring_debug_stats {
 #define RTE_RING_NAMESIZE 32 /**< The maximum length of a ring name. */
 #define RTE_RING_MZ_PREFIX "RG_"
 
+#ifndef RTE_RING_PAUSE_REP_COUNT
+#define RTE_RING_PAUSE_REP_COUNT 0 /**< Yield after pause num of times, no yield
+                                    *   if RTE_RING_PAUSE_REP not defined. */
+#endif
+
 /**
  * An RTE ring structure.
  *
@@ -286,7 +293,6 @@ int rte_ring_init(struct rte_ring *r, const char *name, unsigned count,
  *    rte_errno set appropriately. Possible errno values include:
  *    - E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
  *    - E_RTE_SECONDARY - function was called from a secondary process instance
- *    - E_RTE_NO_TAILQ - no tailq list could be got for the ring list
  *    - EINVAL - count provided is not a power of 2
  *    - ENOSPC - the maximum number of memzones has already been allocated
  *    - EEXIST - a memzone with the same name already exists
@@ -410,7 +416,7 @@ __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
 	uint32_t cons_tail, free_entries;
 	const unsigned max = n;
 	int success;
-	unsigned i;
+	unsigned i, rep = 0;
 	uint32_t mask = r->prod.mask;
 	int ret;
 
@@ -468,9 +474,18 @@ __rte_ring_mp_do_enqueue(struct rte_ring *r, void * const *obj_table,
 	 * If there are other enqueues in progress that preceded us,
 	 * we need to wait for them to complete
 	 */
-	while (unlikely(r->prod.tail != prod_head))
+	while (unlikely(r->prod.tail != prod_head)) {
 		rte_pause();
 
+		/* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
+		 * for other thread finish. It gives pre-empted thread a chance
+		 * to proceed and finish with ring dequeue operation. */
+		if (RTE_RING_PAUSE_REP_COUNT &&
+		    ++rep == RTE_RING_PAUSE_REP_COUNT) {
+			rep = 0;
+			sched_yield();
+		}
+	}
 	r->prod.tail = prod_next;
 	return ret;
 }
@@ -589,7 +604,7 @@ __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
 	uint32_t cons_next, entries;
 	const unsigned max = n;
 	int success;
-	unsigned i;
+	unsigned i, rep = 0;
 	uint32_t mask = r->prod.mask;
 
 	/* move cons.head atomically */
@@ -634,9 +649,18 @@ __rte_ring_mc_do_dequeue(struct rte_ring *r, void **obj_table,
 	 * If there are other dequeues in progress that preceded us,
 	 * we need to wait for them to complete
 	 */
-	while (unlikely(r->cons.tail != cons_head))
+	while (unlikely(r->cons.tail != cons_head)) {
 		rte_pause();
 
+		/* Set RTE_RING_PAUSE_REP_COUNT to avoid spin too long waiting
+		 * for other thread finish. It gives pre-empted thread a chance
+		 * to proceed and finish with ring dequeue operation. */
+		if (RTE_RING_PAUSE_REP_COUNT &&
+		    ++rep == RTE_RING_PAUSE_REP_COUNT) {
+			rep = 0;
+			sched_yield();
+		}
+	}
 	__RING_STAT_ADD(r, deq_success, n);
 	r->cons.tail = cons_next;