qcacld-3.0: Add a yeild break in process rx buffer thread

Some events may send to change the behavior of DP rx thread.
When there are lots of packets pending in rx queue, thread loop
will not get a chance to check and process these events. Change
is aimed to give a yeild to allow checking of thread events.

Change-Id: Ibe64a1ee27086ba8e1ee8c8e9dd316c5fb4a8a42
CRs-Fixed: 3024332

core/dp/txrx3.0/dp_rx_thread.c

@@ -24,9 +24,11 @@
 #include <cdp_txrx_peer_ops.h>
 #include <cds_sched.h>
 
-/* Timeout in ms to wait for a DP rx thread */
 #ifdef HAL_CONFIG_SLUB_DEBUG_ON
+/* Timeout in ms to wait for a DP rx thread */
 #define DP_RX_THREAD_WAIT_TIMEOUT 4000
+/* number of rx pkts that thread should yield */
+#define DP_RX_THREAD_YIELD_PKT_CNT 20000
 #else
 #define DP_RX_THREAD_WAIT_TIMEOUT 2000
 #endif
@@ -390,6 +392,26 @@ static qdf_nbuf_t dp_rx_tm_thread_dequeue(struct dp_rx_thread *rx_thread)
 	return head;
 }
 
+#ifdef CONFIG_SLUB_DEBUG_ON
+/**
+ * dp_rx_thread_should_yield() - check whether rx loop should yield
+ * @iter - iteration of packets recevied
+ *
+ * Returns: should yield or not
+ */
+static inline bool dp_rx_thread_should_yield(uint32_t iter)
+{
+	if (iter >= DP_RX_THREAD_YIELD_PKT_CNT)
+		return true;
+	return false;
+}
+#else
+static inline bool dp_rx_thread_should_yield(uint32_t iter)
+{
+	return false;
+}
+#endif
+
 /**
  * dp_rx_thread_process_nbufq() - process nbuf queue of a thread
  * @rx_thread - rx_thread whose nbuf queue needs to be processed
@@ -404,6 +426,7 @@ static int dp_rx_thread_process_nbufq(struct dp_rx_thread *rx_thread)
 	ol_osif_vdev_handle osif_vdev;
 	ol_txrx_soc_handle soc;
 	uint32_t num_list_elements = 0;
+	uint32_t iterates = 0;
 
 	struct dp_txrx_handle_cmn *txrx_handle_cmn;
 
@@ -427,6 +450,7 @@ static int dp_rx_thread_process_nbufq(struct dp_rx_thread *rx_thread)
 		/* count aggregated RX frame into stats */
 		num_list_elements += qdf_nbuf_get_gso_segs(nbuf_list);
 		rx_thread->stats.nbuf_dequeued += num_list_elements;
+		iterates += num_list_elements;
 
 		vdev_id = QDF_NBUF_CB_RX_VDEV_ID(nbuf_list);
 		cdp_get_os_rx_handles_from_vdev(soc, vdev_id, &stack_fn,
@@ -442,6 +466,10 @@ static int dp_rx_thread_process_nbufq(struct dp_rx_thread *rx_thread)
 			rx_thread->stats.nbuf_sent_to_stack +=
 							num_list_elements;
 		}
+		if (unlikely(dp_rx_thread_should_yield(iterates))) {
+			rx_thread->stats.rx_nbufq_loop_yield++;
+			break;
+		}
 		nbuf_list = dp_rx_tm_thread_dequeue(rx_thread);
 	}
 

core/dp/txrx3.0/dp_rx_thread.h

@@ -59,6 +59,7 @@ struct dp_rx_tm_handle_cmn;
  * @dropped_invalid_peer: packets(nbuf_list) dropped due to no peer
  * @dropped_others: packets dropped due to other reasons
  * @dropped_enq_fail: packets dropped due to pending queue full
+ * @rx_nbufq_loop_yield: rx loop yield counter
  */
 struct dp_rx_thread_stats {
 	unsigned int nbuf_queued[DP_RX_TM_MAX_REO_RINGS];
@@ -74,6 +75,7 @@ struct dp_rx_thread_stats {
 	unsigned int dropped_invalid_os_rx_handles;
 	unsigned int dropped_others;
 	unsigned int dropped_enq_fail;
+	unsigned int rx_nbufq_loop_yield;
 };
 
 /**