pie: use term backlog instead of qlen

Remove ambiguity by using the term backlog instead of qlen when
representing the queue length in bytes.

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/pie.h b/include/net/pie.h
index fd5a37c..24f68c1 100644
--- a/include/net/pie.h
+++ b/include/net/pie.h
@@ -46,7 +46,7 @@ struct pie_params {
  * @accu_prob:			accumulated drop probability
  * @dq_count:			number of bytes dequeued in a measurement cycle
  * @avg_dq_rate:		calculated average dq rate
- * @qlen_old:			queue length during previous qdelay calculation
+ * @backlog_old:		queue backlog during previous qdelay calculation
  * @accu_prob_overflows:	number of times accu_prob overflows
  */
 struct pie_vars {
@@ -58,7 +58,7 @@ struct pie_vars {
 	u64 accu_prob;
 	u64 dq_count;
 	u32 avg_dq_rate;
-	u32 qlen_old;
+	u32 backlog_old;
 	u8 accu_prob_overflows;
 };
 
@@ -127,12 +127,12 @@ static inline void pie_set_enqueue_time(struct sk_buff *skb)
 }
 
 bool pie_drop_early(struct Qdisc *sch, struct pie_params *params,
-		    struct pie_vars *vars, u32 qlen, u32 packet_size);
+		    struct pie_vars *vars, u32 backlog, u32 packet_size);
 
 void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params,
-			 struct pie_vars *vars, u32 qlen);
+			 struct pie_vars *vars, u32 backlog);
 
 void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars,
-			       u32 qlen);
+			       u32 backlog);
 
 #endif