Re: [PATCH v3 net-next 1/2] net-sysfs: display two backlog queue len separately

From: Eric Dumazet
Date: Tue Mar 14 2023 - 11:16:14 EST


On Tue, Mar 14, 2023 at 6:14 AM Jason Xing <kerneljasonxing@xxxxxxxxx> wrote:
>
> From: Jason Xing <kernelxing@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
> ---
> v3: drop the comment suggested by Simon
> Link: https://lore.kernel.org/lkml/20230314030532.9238-2-kerneljasonxing@xxxxxxxxx/
>
> v2: keep the total len of backlog queues untouched as Eric said
> Link: https://lore.kernel.org/lkml/20230311151756.83302-1-kerneljasonxing@xxxxxxxxx/
> ---
> net/core/net-procfs.c | 19 +++++++++++++++----
> 1 file changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
> index 1ec23bf8b05c..8056f39da8a1 100644
> --- a/net/core/net-procfs.c
> +++ b/net/core/net-procfs.c
> @@ -115,10 +115,19 @@ static int dev_seq_show(struct seq_file *seq, void *v)
> return 0;
> }
>
> +static u32 softnet_input_pkt_queue_len(struct softnet_data *sd)
> +{
> + 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 u32 softnet_backlog_len(struct softnet_data *sd)
> {
> - return skb_queue_len_lockless(&sd->input_pkt_queue) +
> - skb_queue_len_lockless(&sd->process_queue);
> + return softnet_input_pkt_queue_len(sd) + softnet_process_queue_len(sd);
> }
>
> static struct softnet_data *softnet_get_online(loff_t *pos)
> @@ -169,12 +178,14 @@ 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);
> + softnet_backlog_len(sd), (int)seq->index,
> + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd));
> return 0;


It is customary to wait ~24 hours between each version, so that
everybody gets a chance to comment,
and to avoid polluting mailing lists with too many messages/day.

(I see you are including lkml@, which seems unnecessary for this kind of patch)

Please address the feedback I gave for v2.

Thanks.