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From: Stephen Rothwell <sfr@canb.auug.org.au>
To: Sven-Haegar Koch <haegar@sdinet.de>
Cc: Eli Cooper <elicooper@gmx.com>,
	netdev@vger.kernel.org, Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: Large performance regression with 6in4 tunnel (sit)
Date: Sun, 27 Nov 2016 14:23:40 +1100	[thread overview]
Message-ID: <20161127142340.3a5c197e@canb.auug.org.au> (raw)
In-Reply-To: <alpine.DEB.2.20.1611250503250.22094@aurora.sdinet.de>

Hi Sven-Haegar,

On Fri, 25 Nov 2016 05:06:53 +0100 (CET) Sven-Haegar Koch <haegar@sdinet.de> wrote:
>
> Somehow this problem description really reminds me of a report on 
> netdev a bit ago, which the following patch fixed:
> 
> commit 9ee6c5dc816aa8256257f2cd4008a9291ec7e985
> Author: Lance Richardson <lrichard@redhat.com>
> Date:   Wed Nov 2 16:36:17 2016 -0400
> 
>     ipv4: allow local fragmentation in ip_finish_output_gso()
>     
>     Some configurations (e.g. geneve interface with default
>     MTU of 1500 over an ethernet interface with 1500 MTU) result
>     in the transmission of packets that exceed the configured MTU.
>     While this should be considered to be a "bad" configuration,
>     it is still allowed and should not result in the sending
>     of packets that exceed the configured MTU.
> 
> Could this be related?
> 
> I suppose it would be difficult to test this patch on this machine?

The kernel I am running on is based on 4.7.8, so the above patch
doesn't come close to applying. Most fo what it is reverting was
introduced in commit 359ebda25aa0 ("net/ipv4: Introduce IPSKB_FRAG_SEGS
bit to inet_skb_parm.flags") in v4.8-rc1.

-- 
Cheers,
Stephen Rothwell

  reply	other threads:[~2016-11-27  3:23 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-25  1:09 Large performance regression with 6in4 tunnel (sit) Stephen Rothwell
2016-11-25  2:18 ` Eli Cooper
2016-11-25  2:45   ` Stephen Rothwell
2016-11-25  3:01     ` Eric Dumazet
2016-11-25  3:09       ` Stephen Rothwell
2016-11-25  3:54         ` Eric Dumazet
2016-11-25  6:12           ` Stephen Rothwell
2016-11-25  4:06     ` Sven-Haegar Koch
2016-11-27  3:23       ` Stephen Rothwell [this message]
2016-11-28 17:54         ` Lance Richardson
2016-11-28 19:49           ` Lance Richardson
2016-11-28 21:32         ` Alexander Duyck
2016-11-28 22:38           ` Stephen Rothwell
2016-11-25  6:05     ` Eli Cooper
2016-11-27  0:54       ` Stephen Rothwell
2016-11-27  2:02         ` Stephen Rothwell
2016-11-27 16:22           ` Eli Cooper
2016-11-25  2:30 ` Eric Dumazet

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