From: Eric Dumazet <edumazet@google.com>
To: Jason Xing <kerneljasonxing@gmail.com>
Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Jason Xing <kernelxing@tencent.com>
Subject: Re: [PATCH net-next] net-sysfs: display two backlog queue len separately
Date: Mon, 13 Mar 2023 05:34:35 -0700 [thread overview]
Message-ID: <CANn89iKWewG7JZXQ=bmab9rSXUs_P5fX-BQ792QjYuH151DV-g@mail.gmail.com> (raw)
In-Reply-To: <20230311151756.83302-1-kerneljasonxing@gmail.com>
On Sat, Mar 11, 2023 at 7:18 AM Jason Xing <kerneljasonxing@gmail.com> wrote:
>
> 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>
> ---
> net/core/net-procfs.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c
> index 1ec23bf8b05c..97a304e1957a 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)
> @@ -169,12 +173,15 @@ 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);
> + 0, /* was len of two backlog queues */
You can not pretend the sum is zero, some user space tools out there
would be fooled.
> + (int)seq->index,
> + softnet_input_pkt_queue_len(sd), softnet_process_queue_len(sd));
> return 0;
> }
>
> --
> 2.37.3
>
In general I would prefer we no longer change this file.
Perhaps add a tracepoint instead ?
next prev parent reply other threads:[~2023-03-13 12:35 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-11 15:17 [PATCH net-next] net-sysfs: display two backlog queue len separately Jason Xing
2023-03-12 19:02 ` Simon Horman
2023-03-13 1:55 ` Jason Xing
2023-03-13 2:28 ` Stephen Hemminger
2023-03-13 2:42 ` Jason Xing
2023-03-13 9:03 ` Jason Xing
2023-03-13 12:11 ` Simon Horman
2023-03-13 12:19 ` Jason Xing
2023-03-13 12:34 ` Eric Dumazet [this message]
2023-03-13 13:15 ` Jason Xing
2023-03-13 15:59 ` Eric Dumazet
2023-03-13 17:15 ` Jason Xing
2023-03-13 17:33 ` Eric Dumazet
2023-03-14 1:54 ` Jason Xing
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