dpdk-hqos: don't hold up packets indefinitely under low load

Change-Id: If884637a6db0cb813a40920194795da2e98c8b23
Signed-off-by: David Hotham <david.hotham@metaswitch.com>
diff --git a/vnet/vnet/devices/dpdk/dpdk.h b/vnet/vnet/devices/dpdk/dpdk.h
index e34d4b9..dfbfce5 100644
--- a/vnet/vnet/devices/dpdk/dpdk.h
+++ b/vnet/vnet/devices/dpdk/dpdk.h
@@ -184,6 +184,7 @@
   u32 hqos_burst_deq;
   u32 pkts_enq_len;
   u32 swq_pos;
+  u32 flush_count;
 } dpdk_device_hqos_per_hqos_thread_t;
 
 typedef struct
@@ -304,6 +305,10 @@
 #define DPDK_HQOS_DBG_BYPASS 0
 #endif
 
+#ifndef HQOS_FLUSH_COUNT_THRESHOLD
+#define HQOS_FLUSH_COUNT_THRESHOLD              100000
+#endif
+
 typedef struct dpdk_device_config_hqos_t
 {
   u32 hqos_thread;