From: Patrick Boutilier <boutilpj@ednet.ns.ca>
To: Tom Herbert <tom@herbertland.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>
Subject: Re: Extreme slowness in IPIP tunnel when routing through kernel 3.18 and later
Date: Thu, 17 Mar 2016 17:30:02 -0300 [thread overview]
Message-ID: <56EB13CA.4040007@ednet.ns.ca> (raw)
In-Reply-To: <CALx6S34YOS=q2-sjK8ZkkRWZ152Y8SBWEP=oxJNM8HTQ-1MhRw@mail.gmail.com>
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On 03/17/2016 01:47 PM, Tom Herbert wrote:
> On Thu, Mar 17, 2016 at 7:02 AM, Patrick Boutilier <boutilpj@ednet.ns.ca> wrote:
>> I have an IPIP tunnel setup between two hosts in different buildings. The
>> Linux router they route through causes extreme slowness in the tunnel when
>> running kernels from 3.18 on . tcpdump shows many cksum errors which don't
>> show up in the 3.17 and earlier kernels. Speed goes back to normal when
>> rx-checksumming and tx-checksumming are turned off using ethtool on the
>> Linux router . Would this be an effect of bulk network packet transmission
>> that was introduced in 3.18 or some other issue?
>>
> If this is happening on a router then the only case where checksums
> are pertinent should be if GSO/GRO is enabled. Please try disabling
> these. Also, are these showing up as checksum errors on the receiver
> (netstat -s).
Yes, turning off GSO/GRO also fixes the issue.
Not sure which value of netstat I am looking for.
Compiling a new kernel now with Jesse's patch to test. Will report back
in a bit.
>
>
>>
>> eth2
>> driver: igb
>> version: 5.2.15-k
>> firmware-version: 1.5.1
>> bus-info: 0000:06:00.0
>> supports-statistics: yes
>> supports-test: yes
>> supports-eeprom-access: yes
>> supports-register-dump: yes
>> supports-priv-flags: no
>>
>>
>> eth6
>> driver: ixgbe
>> version: 3.19.1-k
>> firmware-version: 0x80000389
>> bus-info: 0000:41:00.0
>> supports-statistics: yes
>> supports-test: yes
>> supports-eeprom-access: yes
>> supports-register-dump: yes
>> supports-priv-flags: no
>>
>>
>>
>>
>>
>> Example of cksum from tcpdump:
>>
>> Flags [.], cksum 0x2237 (incorrect -> 0xbb02), seq 424119200:424120648, ack
>> 1, win 115, options [nop,nop,TS val 303173784 ecr 3971495454], length 1448
>>
>>
>>
>>
>>
>> Results of nuttcp test with rx-checksumming and tx-checksumming on:
>>
>>
>> Testing upload inside tunnel
>>
>>
>>
>> 0.0625 MB / 5.00 sec = 0.1048 Mbps 79 retrans
>> 0.0625 MB / 5.00 sec = 0.1048 Mbps 59 retrans
>> 0.0625 MB / 5.00 sec = 0.1049 Mbps 27 retrans
>>
>> 0.2096 MB / 16.11 sec = 0.1092 Mbps 0 %TX 0 %RX 186 retrans 0.47
>> msRTT
>>
>>
>>
>> Testing download inside tunnel
>>
>>
>>
>> 0.5000 MB / 5.00 sec = 0.8389 Mbps 112 retrans
>> 2.6250 MB / 5.00 sec = 4.4040 Mbps 412 retrans
>> 0.8750 MB / 5.00 sec = 1.4680 Mbps 156 retrans
>>
>> 4.0243 MB / 15.48 sec = 2.1809 Mbps 0 %TX 0 %RX 705 retrans 0.47
>> msRTT
>>
>>
>> Testing upload outside tunnel
>>
>>
>>
>> 423.0000 MB / 5.00 sec = 709.4949 Mbps 275 retrans
>> 442.0625 MB / 5.00 sec = 741.7008 Mbps 53 retrans
>> 418.5625 MB / 5.00 sec = 702.1329 Mbps 133 retrans
>>
>> 1287.0080 MB / 15.08 sec = 715.9252 Mbps 1 %TX 30 %RX 461 retrans 0.43
>> msRTT
>>
>>
>>
>> Testing download outside tunnel
>>
>>
>>
>> 552.4375 MB / 5.00 sec = 926.8347 Mbps 26 retrans
>> 555.1875 MB / 5.00 sec = 931.4499 Mbps 17 retrans
>> 553.0000 MB / 5.00 sec = 927.7802 Mbps 16 retrans
>>
>> 1664.2149 MB / 15.03 sec = 928.6737 Mbps 9 %TX 5 %RX 60 retrans 0.46
>> msRTT
>>
>>
>>
>>
>>
>>
>> Results of nuttcp test with rx-checksumming and tx-checksumming off:
>>
>>
>>
>> Testing upload inside tunnel
>>
>>
>>
>> 440.0000 MB / 5.00 sec = 738.0112 Mbps 117 retrans
>> 433.0000 MB / 5.00 sec = 726.4892 Mbps 135 retrans
>> 447.9375 MB / 5.00 sec = 751.5714 Mbps 112 retrans
>>
>> 1321.0069 MB / 15.04 sec = 736.7213 Mbps 3 %TX 21 %RX 364 retrans 0.51
>> msRTT
>>
>>
>>
>> Testing download inside tunnel
>>
>>
>>
>> 494.0625 MB / 5.00 sec = 828.8973 Mbps 335 retrans
>> 471.0000 MB / 5.00 sec = 790.2050 Mbps 219 retrans
>> 469.8750 MB / 5.00 sec = 788.3174 Mbps 220 retrans
>>
>> 1435.1875 MB / 15.00 sec = 802.4203 Mbps 89 %TX 12 %RX 774 retrans 0.46
>> msRTT
>>
>>
>> Testing upload outside tunnel
>>
>>
>>
>> 431.2500 MB / 5.00 sec = 723.2808 Mbps 33 retrans
>> 446.3750 MB / 5.00 sec = 748.9268 Mbps 10 retrans
>> 475.4375 MB / 5.00 sec = 797.7044 Mbps 0 retrans
>>
>> 1355.0834 MB / 15.06 sec = 754.6438 Mbps 1 %TX 33 %RX 43 retrans 0.53
>> msRTT
>>
>>
>>
>> Testing download outside tunnel
>>
>>
>>
>> 424.8125 MB / 5.00 sec = 712.7061 Mbps 102 retrans
>> 456.5625 MB / 5.00 sec = 765.9872 Mbps 80 retrans
>> 454.0000 MB / 5.00 sec = 761.6935 Mbps 116 retrans
>>
>> 1335.7823 MB / 15.01 sec = 746.6959 Mbps 4 %TX 5 %RX 298 retrans 0.55
>> msRTT
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fn:Patrick Boutilier
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title:WAN Communications Specialist
tel;work:902-424-6800
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version:2.1
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next prev parent reply other threads:[~2016-03-17 20:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-17 14:02 Extreme slowness in IPIP tunnel when routing through kernel 3.18 and later Patrick Boutilier
2016-03-17 16:47 ` Tom Herbert
2016-03-17 20:30 ` Patrick Boutilier [this message]
2016-03-17 18:27 ` Jesse Gross
2016-03-17 21:13 ` Patrick Boutilier
2016-03-17 21:18 ` Jesse Gross
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