From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yuchung Cheng <ycheng@google.com>
Subject: Re: 3.10.0 network trace
Date: Sat, 20 Jul 2013 23:04:56 -0700
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To: Michael Sterrett <michael@sterretts.net>
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On Sat, Jul 13, 2013 at 2:10 PM, Michael Sterrett <michael@sterretts.net> wrote:
> After changing those two sysctl settings the WARN hasn't reappeared.
> I'm willing to mess around with this box though if you want to try to
> narrow down the root cause with different settings and/or patches.
Could you try to disable F-RTO but enable loss probe by
sysctl net.ipv4.tcp_frto=0 net.ipv4.tcp_early_retrans=3
to help us identify if this is loss probe bug or f-rto. Thanks.

>
> On Fri, Jul 12, 2013 at 5:39 PM, Yuchung Cheng <ycheng@google.com> wrote:
>> On Fri, Jul 12, 2013 at 2:33 PM, Michael Sterrett <michael@sterretts.net> wrote:
>>> Thanks for the reply.  The sysctl -a output is attached.
>>
>> Hi Michael: my guess is some of the recent changes like TLP or F-RTO
>> rewrite has bugs. It'd be best if you can provide tcp traces that
>> triggers this. If not and this WARN appears frequently enough, please
>> try i) sysctl tcp_early_retrans=2 ii) sysctl tcp_frto=0 and see if
>> that WARN goes away. Thanks.