[PATCH v4 net-next 1/2] net-sysfs: display two backlog queue len separately

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

Sometimes we need to know which one of backlog queue can be exactly
long enough to cause some latency when debugging this part is needed.
Thus, we can then separate the display of both.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
---
v4:
1) avoid the inconsistency through caching variables suggested
by Eric.
Link: https://lore.kernel.org/lkml/20230314030532.9238-2-kerneljasonxing@gmail.com/
2) remove the unused function: softnet_backlog_len()

v3: drop the comment suggested by Simon
Link: https://lore.kernel.org/lkml/20230314030532.9238-2-kerneljasonxing@gmail.com/

v2: keep the total len of backlog queues untouched as Eric said
Link: https://lore.kernel.org/lkml/20230311151756.83302-1-kerneljasonxing@gmail.com/
---
 net/core/net-procfs.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
index 1ec23bf8b05c..09f7ed1a04e8 100644
--- a/net/core/net-procfs.c
+++ b/net/core/net-procfs.c
@@ -115,10 +115,14 @@ static int dev_seq_show(struct seq_file *seq, void *v)
 	return 0;
 }
 
-static u32 softnet_backlog_len(struct softnet_data *sd)
+static u32 softnet_input_pkt_queue_len(struct softnet_data *sd)
 {
-	return skb_queue_len_lockless(&sd->input_pkt_queue) +
-	       skb_queue_len_lockless(&sd->process_queue);
+	return skb_queue_len_lockless(&sd->input_pkt_queue);
+}
+
+static u32 softnet_process_queue_len(struct softnet_data *sd)
+{
+	return skb_queue_len_lockless(&sd->process_queue);
 }
 
 static struct softnet_data *softnet_get_online(loff_t *pos)
@@ -152,6 +156,8 @@ static void softnet_seq_stop(struct seq_file *seq, void *v)
 static int softnet_seq_show(struct seq_file *seq, void *v)
 {
 	struct softnet_data *sd = v;
+	u32 input_qlen = softnet_input_pkt_queue_len(sd);
+	u32 process_qlen = softnet_process_queue_len(sd);
 	unsigned int flow_limit_count = 0;
 
 #ifdef CONFIG_NET_FLOW_LIMIT
@@ -169,12 +175,14 @@ static int softnet_seq_show(struct seq_file *seq, void *v)
 	 * mapping the data a specific CPU
 	 */
 	seq_printf(seq,
-		   "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
+		   "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x %08x "
+		   "%08x %08x\n",
 		   sd->processed, sd->dropped, sd->time_squeeze, 0,
 		   0, 0, 0, 0, /* was fastroute */
 		   0,	/* was cpu_collision */
 		   sd->received_rps, flow_limit_count,
-		   softnet_backlog_len(sd), (int)seq->index);
+		   input_qlen + process_qlen, (int)seq->index,
+		   input_qlen, process_qlen);
 	return 0;
 }
 
-- 
2.37.3