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From: "Thomas Rosenstein" <thomas.rosenstein@creamfinance.com>
To: "Jesper Dangaard Brouer" <brouer@redhat.com>
Cc: "Thomas Rosenstein via Bloat" <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] Router congestion, slow ping/ack times with kernel 5.4.60
Date: Mon, 09 Nov 2020 17:39:48 +0100	[thread overview]
Message-ID: <81F2B741-3F76-4AE1-84EB-DC65AD2BB798@creamfinance.com> (raw)
In-Reply-To: <20201109124030.71216677@carbon>

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On 9 Nov 2020, at 12:40, Jesper Dangaard Brouer wrote:

> On Mon, 09 Nov 2020 11:09:33 +0100
> "Thomas Rosenstein" <thomas.rosenstein@creamfinance.com> wrote:
>
> Could you also provide ethtool_stats for the TX interface?
>
> Notice that the tool[1] ethtool_stats.pl support monitoring several
> interfaces at the same time, e.g. run:
>
>  ethtool_stats.pl --sec 3 --dev eth4 --dev ethTX
>
> And provide output as pastebin.

I have now also repeated the same test with 3.10, here are the ethtool 
outputs:

https://drive.google.com/file/d/1c98MVV0JYl6Su6xZTpqwS7m-6OlbmAFp/view?usp=sharing

and the ping times:

https://drive.google.com/file/d/1xhbGJHb5jUbPsee4frbx-c-uqh-7orXY/view?usp=sharing

Sadly the parameters we were looking at are not supported below 4.14.

but I immediatly saw 1 thing very different:

ethtool --statistics eth4 | grep discards
      rx_discards_phy: 0
      tx_discards_phy: 0

if we check the ethtool output from 5.9.4 were have:

      rx_discards_phy: 151793

And also the outbound_pci_stalled_wr_events get more frequent the lower 
the total bandwidth / the higher the ping is.
Logically there must be something blocking the the buffers, either they 
are not getting freed, or not rotated correctly, or processing is too 
slow.
I would exclude the processing, simply based on 0% CPU load, and also 
that it doesn't happen in 3.10.
Suspicious is also, that the issue only appears after a certain time of 
activity (maybe total traffic?!)



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  parent reply	other threads:[~2020-11-09 16:39 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-04 15:23 Thomas Rosenstein
2020-11-04 16:10 ` Toke Høiland-Jørgensen
2020-11-04 16:24   ` Thomas Rosenstein
2020-11-05  0:10     ` Toke Høiland-Jørgensen
2020-11-05  8:48       ` Thomas Rosenstein
2020-11-05 11:21         ` Toke Høiland-Jørgensen
2020-11-05 12:22           ` Thomas Rosenstein
2020-11-05 12:38             ` Toke Høiland-Jørgensen
2020-11-05 12:41               ` Thomas Rosenstein
2020-11-05 12:47                 ` Toke Høiland-Jørgensen
2020-11-05 13:33             ` Jesper Dangaard Brouer
2020-11-06  8:48               ` Thomas Rosenstein
2020-11-06 10:53                 ` Jesper Dangaard Brouer
2020-11-06  9:18               ` Thomas Rosenstein
2020-11-06 11:18                 ` Jesper Dangaard Brouer
2020-11-06 11:37                   ` Thomas Rosenstein
2020-11-06 11:45                     ` Toke Høiland-Jørgensen
2020-11-06 12:01                       ` Thomas Rosenstein
2020-11-06 12:53                       ` Jesper Dangaard Brouer
2020-11-06 14:13                         ` Jesper Dangaard Brouer
2020-11-06 17:04                           ` Thomas Rosenstein
2020-11-06 20:19                             ` Jesper Dangaard Brouer
2020-11-07 12:37                               ` Thomas Rosenstein
2020-11-07 12:40                                 ` Jan Ceuleers
2020-11-07 12:43                                   ` Thomas Rosenstein
2020-11-07 13:00                                   ` Thomas Rosenstein
2020-11-09  8:24                                     ` Jesper Dangaard Brouer
2020-11-09 10:09                                       ` Thomas Rosenstein
2020-11-09 11:40                                         ` Jesper Dangaard Brouer
2020-11-09 11:51                                           ` Toke Høiland-Jørgensen
2020-11-09 12:25                                           ` Thomas Rosenstein
2020-11-09 14:33                                           ` Thomas Rosenstein
2020-11-12 10:05                                             ` Jesper Dangaard Brouer
2020-11-12 11:26                                               ` Thomas Rosenstein
2020-11-12 13:31                                                 ` Jesper Dangaard Brouer
2020-11-12 13:42                                                   ` Thomas Rosenstein
2020-11-12 15:42                                                     ` Jesper Dangaard Brouer
2020-11-13  6:31                                                       ` Thomas Rosenstein
2020-11-16 11:56                                                         ` Jesper Dangaard Brouer
2020-11-16 12:05                                                           ` Thomas Rosenstein
2020-11-09 16:39                                           ` Thomas Rosenstein [this message]
2020-11-07 13:33                                 ` Thomas Rosenstein
2020-11-07 16:46                                 ` Jesper Dangaard Brouer
2020-11-07 17:01                                   ` Thomas Rosenstein
2020-11-07 17:26                                     ` Sebastian Moeller
2020-11-16 12:34 ` Jesper Dangaard Brouer
2020-11-16 12:49   ` Thomas Rosenstein

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