[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <20230108163403.37e3f25d@rorschach.local.home>
Date: Sun, 8 Jan 2023 16:34:03 -0500
From: Steven Rostedt <rostedt@...dmis.org>
To: Yunhui Cui <cuiyunhui@...edance.com>
Cc: mhiramat@...nel.org, davem@...emloft.net, edumazet@...gle.com,
kuba@...nel.org, pabeni@...hat.com, kuniyu@...zon.com,
xiyou.wangcong@...il.com, duanxiongchun@...edance.com,
linux-kernel@...r.kernel.org, linux-trace-kernel@...r.kernel.org,
netdev@...r.kernel.org
Subject: Re: [PATCH v3] sock: add tracepoint for send recv length
On Sat, 7 Jan 2023 11:59:23 +0800
Yunhui Cui <cuiyunhui@...edance.com> wrote:
> Add 2 tracepoints to monitor the tcp/udp traffic
> of per process and per cgroup.
>
> Regarding monitoring the tcp/udp traffic of each process, there are two
> existing solutions, the first one is https://www.atoptool.nl/netatop.php.
> The second is via kprobe/kretprobe.
>
> Netatop solution is implemented by registering the hook function at the
> hook point provided by the netfilter framework.
>
> These hook functions may be in the soft interrupt context and cannot
> directly obtain the pid. Some data structures are added to bind packets
> and processes. For example, struct taskinfobucket, struct taskinfo ...
>
> Every time the process sends and receives packets it needs multiple
> hashmaps,resulting in low performance and it has the problem fo inaccurate
> tcp/udp traffic statistics(for example: multiple threads share sockets).
>
> We can obtain the information with kretprobe, but as we know, kprobe gets
> the result by trappig in an exception, which loses performance compared
> to tracepoint.
>
> We compared the performance of tracepoints with the above two methods, and
> the results are as follows:
>
> ab -n 1000000 -c 1000 -r http://127.0.0.1/index.html
> without trace:
> Time per request: 39.660 [ms] (mean)
> Time per request: 0.040 [ms] (mean, across all concurrent requests)
>
> netatop:
> Time per request: 50.717 [ms] (mean)
> Time per request: 0.051 [ms] (mean, across all concurrent requests)
>
> kr:
> Time per request: 43.168 [ms] (mean)
> Time per request: 0.043 [ms] (mean, across all concurrent requests)
>
> tracepoint:
> Time per request: 41.004 [ms] (mean)
> Time per request: 0.041 [ms] (mean, across all concurrent requests
>
> It can be seen that tracepoint has better performance.
>
> Signed-off-by: Yunhui Cui <cuiyunhui@...edance.com>
> Signed-off-by: Xiongchun Duan <duanxiongchun@...edance.com>
> ---
>From a tracing POV:
Reviewed-by: Steven Rostedt (Google) <rostedt@...dmis.org>
-- Steve
Powered by blists - more mailing lists