LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Paolo Abeni <pabeni@redhat.com>
To: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>,
John Fastabend <john.fastabend@gmail.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: Mon, 19 Mar 2018 13:32:30 +0100 [thread overview]
Message-ID: <1521462750.3059.12.camel@redhat.com> (raw)
In-Reply-To: <340a6c54-6031-5522-98f5-eafdd3a37a38@theobroma-systems.com>
Hi,
On Fri, 2018-03-16 at 11:26 +0100, Jakob Unterwurzacher wrote:
> On 15.03.18 23:30, John Fastabend wrote:
> > > 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.
>
> Interesting. Looks like it depends on which core it runs on. CPU0 is
> clean, CPU1 is not.
>
> Clean: taskset --cpu-list 0 ./pfifo_stress.py
>
> Broken: taskset --cpu-list 1 ./pfifo_stress.py
>
> Maybe related: CPU0 is where USB interrupts are handled:
>
> > root@rk3399-q7:~# cat /proc/interrupts
> > CPU0 CPU1 CPU2 CPU3 CPU4 CPU5
> > 217: 2175353 0 0 0 0 0 GICv3 142 Level xhci-hcd:usb5
Is not clear to me if you can reproduce the bug with the vanilla
kernel, or if you need some out-of-tree nic driver. Can you please
clarify which NIC/driver are you using?
Thanks,
Paolo
next prev parent reply other threads:[~2018-03-19 12:32 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
2018-03-16 10:26 ` Jakob Unterwurzacher
2018-03-19 6:07 ` Alexander Stein
2018-03-19 12:32 ` Paolo Abeni [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1521462750.3059.12.camel@redhat.com \
--to=pabeni@redhat.com \
--cc=dave.taht@gmail.com \
--cc=davem@davemloft.net \
--cc=jakob.unterwurzacher@theobroma-systems.com \
--cc=john.fastabend@gmail.com \
--cc=linux-can@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=martin.elshuber@theobroma-systems.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).