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From: Michal Kubecek <mkubecek@suse.cz>
To: Yunsheng Lin <linyunsheng@huawei.com>
Cc: davem@davemloft.net, kuba@kernel.org, olteanv@gmail.com,
	ast@kernel.org, daniel@iogearbox.net, andriin@fb.com,
	edumazet@google.com, weiwan@google.com, cong.wang@bytedance.com,
	ap420073@gmail.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, linuxarm@openeuler.org,
	mkl@pengutronix.de, linux-can@vger.kernel.org, jhs@mojatatu.com,
	xiyou.wangcong@gmail.com, jiri@resnulli.us, andrii@kernel.org,
	kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org,
	bpf@vger.kernel.org, pabeni@redhat.com, mzhivich@akamai.com,
	johunt@akamai.com, albcamus@gmail.com, kehuan.feng@gmail.com,
	a.fatoum@pengutronix.de, atenart@kernel.org,
	alexander.duyck@gmail.com, hdanton@sina.com, jgross@suse.com,
	JKosina@suse.com
Subject: Re: [PATCH net v4 1/2] net: sched: fix packet stuck problem for lockless qdisc
Date: Fri, 30 Apr 2021 08:28:46 +0200	[thread overview]
Message-ID: <20210430062846.vrdf7ggsgskkhgzp@lion.mk-sys.cz> (raw)
In-Reply-To: <f06355b4-2b00-fc52-4d9d-9c866436e559@huawei.com>

On Fri, Apr 30, 2021 at 11:15:01AM +0800, Yunsheng Lin wrote:
> On 2021/4/30 11:11, Yunsheng Lin wrote:
> > On 2021/4/23 17:42, Yunsheng Lin wrote:
> >> On 2021/4/21 17:25, Yunsheng Lin wrote:
> >>> On 2021/4/21 16:44, Michal Kubecek wrote:
> >>>
> >>>>
> >>>> I'll try running some tests also on other architectures, including arm64
> >>>> and s390x (to catch potential endinanity issues).
> >>
> >> I tried debugging nperf in arm64, with the below patch:
> >>
> >> Any idea what went wrong here?
> >>
> >> Also, Would you mind running netperf to see if there is similar issue
> >> in your system?
> > 
> > Hi, Michal
> >     I was able to reproduce the fluctuation for one thread TCP_STREAM test,
> 
> I was *not* able
> Sorry for the typo.

I was able to reproduce the same problem with netperf:

marfak:~ # for i in {1..60}; do netperf -H 172.17.1.1 -l 30 -t TCP_STREAM -- -m 1048576; done
131072  16384 1048576    30.00    9413.36   
131072  16384 1048576    30.01    7473.68   <---
131072  16384 1048576    30.00    9413.97   
131072  16384 1048576    30.00    9413.76   
131072  16384 1048576    30.01    9024.25   
131072  16384 1048576    30.01    8364.78   
131072  16384 1048576    30.00    9413.22   
131072  16384 1048576    30.00    9414.29   
131072  16384 1048576    30.00    9414.32   
131072  16384 1048576    30.00    9412.58   
131072  16384 1048576    30.00    9412.79   
131072  16384 1048576    30.00    9413.18   
131072  16384 1048576    30.01    8771.57   <---
131072  16384 1048576    30.00    9414.01   
131072  16384 1048576    30.00    9413.93   
131072  16384 1048576    30.00    9413.97   
131072  16384 1048576    30.00    9414.05   
131072  16384 1048576    30.00    9412.92   
131072  16384 1048576    30.00    9413.40   
131072  16384 1048576    30.00    9414.41   
131072  16384 1048576    30.00    9413.25   
131072  16384 1048576    30.00    9413.38   
131072  16384 1048576    30.00    9412.28   
131072  16384 1048576    30.00    9413.50   
131072  16384 1048576    30.00    9414.12   
131072  16384 1048576    30.00    9414.27   
131072  16384 1048576    30.00    9412.96   
131072  16384 1048576    30.00    9413.71   
131072  16384 1048576    30.01    9205.98   
131072  16384 1048576    30.00    9413.69   
131072  16384 1048576    30.00    9413.60   
131072  16384 1048576    30.01    8297.03   <---
131072  16384 1048576    30.00    9414.09   
131072  16384 1048576    30.00    9414.38   
131072  16384 1048576    30.00    9413.62   
131072  16384 1048576    30.00    9411.09   
131072  16384 1048576    30.00    9414.37   
131072  16384 1048576    30.00    9414.37   
131072  16384 1048576    30.00    9412.52   
131072  16384 1048576    30.00    9414.06   
131072  16384 1048576    30.00    9413.66   
131072  16384 1048576    30.00    9411.63   
131072  16384 1048576    30.00    9414.17   
131072  16384 1048576    30.00    9414.07   
131072  16384 1048576    30.00    9414.09   
131072  16384 1048576    30.00    9414.37   
131072  16384 1048576    30.00    9390.00   
131072  16384 1048576    30.00    9413.72   
131072  16384 1048576    30.01    9260.97   
131072  16384 1048576    30.01    9334.91   
131072  16384 1048576    30.00    9413.57   
131072  16384 1048576    30.00    9412.01   
131072  16384 1048576    30.00    9414.36   
131072  16384 1048576    30.00    9412.47   
131072  16384 1048576    30.00    9413.73   
131072  16384 1048576    30.00    9413.48   
131072  16384 1048576    30.00    9413.36   
131072  16384 1048576    30.01    9327.42   
131072  16384 1048576    30.01    9240.33   
131072  16384 1048576    30.00    9413.97   

(filtered only the interesting lines)

But after some more testing, I was also able to see similar results with
unpatched mainline kernel:

131072  16384 1048576    30.00    9413.28   
131072  16384 1048576    30.01    9007.17   
131072  16384 1048576    30.01    9153.22   
131072  16384 1048576    30.00    9414.28   
131072  16384 1048576    30.01    9244.68   
131072  16384 1048576    30.01    9230.49   
131072  16384 1048576    30.00    8723.24   <---
131072  16384 1048576    30.01    8289.21   <---
131072  16384 1048576    30.01    9258.33   
131072  16384 1048576    30.00    9251.47   
131072  16384 1048576    30.00    9414.23   
131072  16384 1048576    30.01    9276.87   
131072  16384 1048576    30.01    9255.61   
131072  16384 1048576    30.00    9072.78   
131072  16384 1048576    30.00    9412.09   
131072  16384 1048576    30.01    9393.00   
131072  16384 1048576    30.00    9413.39   
131072  16384 1048576    30.01    9404.01   
131072  16384 1048576    30.01    8412.83   <---
131072  16384 1048576    30.01    9368.23   
131072  16384 1048576    30.01    9259.11   
131072  16384 1048576    30.01    9121.65   
131072  16384 1048576    30.01    9169.87   
131072  16384 1048576    30.01    9154.03   
131072  16384 1048576    30.01    9336.34   
131072  16384 1048576    30.00    9187.73   
131072  16384 1048576    30.00    9412.54   
131072  16384 1048576    30.01    6836.37   <---
131072  16384 1048576    30.01    9388.09   
131072  16384 1048576    30.01    8755.78   <---
131072  16384 1048576    30.01    9167.63   
131072  16384 1048576    30.00    9410.80   
131072  16384 1048576    30.01    9392.71   
131072  16384 1048576    30.01    9238.50   
131072  16384 1048576    30.01    9382.78   
131072  16384 1048576    30.01    9328.23   
131072  16384 1048576    30.01    9396.04   
131072  16384 1048576    30.01    9286.10   
131072  16384 1048576    30.00    9412.44   
131072  16384 1048576    30.01    7952.34   <---
131072  16384 1048576    30.01    9309.95   
131072  16384 1048576    30.00    9133.38   
131072  16384 1048576    30.01    8672.75   
131072  16384 1048576    30.00    9414.28   
131072  16384 1048576    30.00    9411.34   
131072  16384 1048576    30.00    9414.27   
131072  16384 1048576    30.01    9313.60   
131072  16384 1048576    30.01    9315.10   
131072  16384 1048576    30.00    9413.23   
131072  16384 1048576    30.01    9285.77   
131072  16384 1048576    30.00    9414.28   
131072  16384 1048576    30.00    9406.39   
131072  16384 1048576    30.01    9343.74   
131072  16384 1048576    30.01    9179.17   
131072  16384 1048576    30.01    9081.18   
131072  16384 1048576    30.00    9412.85   
131072  16384 1048576    30.00    9413.66   
131072  16384 1048576    30.01    9346.16   
131072  16384 1048576    30.00    9410.01   
131072  16384 1048576    30.00    9411.22   

It's not clear why I haven't seen these before but the problem is
unlikely to by related to your patch set.

Michal

  reply	other threads:[~2021-04-30  6:28 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-16  1:16 [PATCH net v4 0/2] fix packet stuck problem for lockless qdisc Yunsheng Lin
2021-04-16  1:16 ` [PATCH net v4 1/2] net: sched: " Yunsheng Lin
2021-04-19 15:29   ` Michal Kubecek
2021-04-19 23:55     ` Michal Kubecek
2021-04-20  2:23       ` Yunsheng Lin
2021-04-20 20:34       ` Michal Kubecek
2021-04-21  1:52         ` Yunsheng Lin
2021-04-21  5:31           ` Michal Kubecek
2021-04-21  8:21             ` Yunsheng Lin
2021-04-21  8:44               ` Michal Kubecek
2021-04-21  9:25                 ` Yunsheng Lin
2021-04-23  9:42                   ` Yunsheng Lin
2021-04-30  3:11                     ` Yunsheng Lin
2021-04-30  3:15                       ` Yunsheng Lin
2021-04-30  6:28                         ` Michal Kubecek [this message]
2021-04-16  1:16 ` [PATCH net v4 2/2] net: sched: fix endless tx action reschedule during deactivation Yunsheng Lin

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