From: "Ortwin Glück" <odi@odi.ch>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: 3.14 regression: huge latency in read/select on tun
Date: Thu, 03 Apr 2014 09:52:26 +0200 [thread overview]
Message-ID: <533D133A.3090008@odi.ch> (raw)
In-Reply-To: <1396456973.3989.41.camel@edumazet-glaptop2.roam.corp.google.com>
[-- Attachment #1: Type: text/plain, Size: 768 bytes --]
On 02.04.2014 18:42, Eric Dumazet wrote:
> You could post a tcpdump maybe ?
This is a dump from on the tun interface (traffic inside the tunnel).
It's an scp upload of a 2MB file. I aborted after a while when not much
progress was seen anymore, but you get the idea.
What I see:
- Frame 28: long delay because I had to enter the key password
- Frame 31: the packets seems to be out of order. It has a sequence
number that is far ahead of previously sent sequence no's. Some
duplicates and retransmissions follow. That pattern repeats randomly all
over the trace.
- from Frame 73 on: ping pong of ACKs and data, while the data is
delayed by ~200ms caused by the select(). The ping pong also shows that
there are virtually no packets in flight (see also Window size).
[-- Attachment #2: dump.pcapng --]
[-- Type: application/octet-stream, Size: 842792 bytes --]
next prev parent reply other threads:[~2014-04-03 7:52 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-02 16:17 3.14 regression: huge latency in read/select on tun Ortwin Glück
2014-04-02 16:42 ` Eric Dumazet
2014-04-03 7:52 ` Ortwin Glück [this message]
2014-04-03 13:19 ` Eric Dumazet
2014-04-03 13:50 ` Eric Dumazet
2014-04-04 8:34 ` Ortwin Glück
2014-04-19 20:13 ` Ortwin Glück
2014-04-20 16:31 ` Eric Dumazet
2014-04-21 8:40 ` Ortwin Glück
2014-04-21 11:13 ` Lukas Tribus
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