From: John Fastabend <john.fastabend@gmail.com>
To: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>,
Dave Taht <dave.taht@gmail.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
"linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
Martin Elshuber <martin.elshuber@theobroma-systems.com>
Subject: Re: [bug, bisected] pfifo_fast causes packet reordering
Date: Thu, 15 Mar 2018 15:30:55 -0700 [thread overview]
Message-ID: <5aeb54ba-2d96-4ab5-53c4-2d3691be7acc@gmail.com> (raw)
In-Reply-To: <3a959e50-8656-5d9c-97b9-227d733948f8@theobroma-systems.com>
On 03/15/2018 11:08 AM, Jakob Unterwurzacher wrote:
> On 14.03.18 05:03, John Fastabend wrote:
>> On 03/13/2018 11:35 AM, Dave Taht wrote:
>>> On Tue, Mar 13, 2018 at 11:24 AM, Jakob Unterwurzacher
>>> <jakob.unterwurzacher@theobroma-systems.com> wrote:
>>>> During stress-testing our "ucan" USB/CAN adapter SocketCAN driver on Linux
>>>> v4.16-rc4-383-ged58d66f60b3 we observed that a small fraction of packets are
>>>> delivered out-of-order.
>>>>
>>
>> Is the stress-testing tool available somewhere? What type of packets
>> are being sent?
>
>
> I have reproduced it using two USB network cards connected to each other. The test tool sends UDP packets containing a counter and listens on the other interface, it is available at
> https://github.com/jakob-tsd/pfifo_stress/blob/master/pfifo_stress.py
>
Great thanks, can you also run this with taskset to bind to
a single CPU,
# taskset 0x1 ./pifof_stress.py
And let me know if you still see the OOO.
> Here is what I get:
>
> root@rk3399-q7:~# ./pfifo_stress.py
> [...]
> expected ctr 0xcdc, received 0xcdd
> expected ctr 0xcde, received 0xcdc
> expected ctr 0xcdd, received 0xcde
> expected ctr 0xe3c, received 0xe3d
> expected ctr 0xe3e, received 0xe3c
> expected ctr 0xe3d, received 0xe3e
> expected ctr 0x1097, received 0x1098
> expected ctr 0x1099, received 0x1097
> expected ctr 0x1098, received 0x1099
> expected ctr 0x17c0, received 0x17c1
> expected ctr 0x17c2, received 0x17c0
> [...]
>
> Best regards,
> Jakob
next prev parent reply other threads:[~2018-03-15 22:31 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 18:24 [bug, bisected] pfifo_fast causes packet reordering Jakob Unterwurzacher
2018-03-13 18:35 ` Dave Taht
2018-03-14 4:03 ` John Fastabend
2018-03-14 10:09 ` Jakob Unterwurzacher
2018-03-15 18:08 ` Jakob Unterwurzacher
2018-03-15 22:30 ` John Fastabend [this message]
2018-03-16 10:26 ` Jakob Unterwurzacher
2018-03-19 6:07 ` Alexander Stein
2018-03-19 12:32 ` Paolo Abeni
2018-03-19 12:56 ` Jakob Unterwurzacher
2018-03-21 10:01 ` Jakob Unterwurzacher
2018-03-21 18:43 ` John Fastabend
2018-03-21 19:44 ` Jakob Unterwurzacher
2018-03-21 20:52 ` John Fastabend
2018-03-22 10:16 ` Jakob Unterwurzacher
2018-03-24 14:26 ` John Fastabend
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