mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Esko Mobius <echoowall@gmail.com>
To: Neal Cardwell <ncardwell@google.com>
Cc: davem@davemloft.net, edumazet@kernel.org, pabeni@redhat.com,
	shuah@kernel.org, kuniyu@google.com, horms@kernel.org,
	kuba@kernel.org, netdev@vger.kernel.org, panweiping3@gmail.com,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: Re: [PATCH net-next v3 3/4] selftests/net: packetdrill: add TCP black hole detection test
Date: Wed, 11 Nov 2026 00:49:06 +0800	[thread overview]
Message-ID: <18B3E417-AC3D-4A70-88BD-4ADA9003ACAF@gmail.com> (raw)
In-Reply-To: <CADVnQykoJWJL+vZ9GC=RqZuiSEypNtmTONBzV7XRQ1jsXy0X_A@mail.gmail.com>

> So I'd suggest renaming this case to be something like
> tcp_mtu_probing_blackhole_no_tlp_retries1_is_1.pkt.
>
> Then I'd suggest creating a test like this, but with only the following setting:
>
> `./defaults.sh
> sysctl -q net.ipv4.tcp_mtu_probing=1`

Thanks, Neal. That makes sense.

I renamed this case and added a test that only sets tcp_mtu_probing=1
on top of defaults.sh. With the default settings, the TLP and the first
three RTO retransmissions keep the full size. The fourth RTO falls back
to tcp_base_mss, about 4.8 seconds after the original transmission.

The new test passes in all three IP modes on x86_64 KVM. v4 has both
tests.

Thanks,
Yongjian

  reply	other threads:[~2026-11-10 16:49 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-09 16:44 [PATCH net-next v3 0/4] tcp: fix tcp_base_mss on passive connections and test MTU probing Yongjian Wang via B4 Relay
2026-11-09 16:44 ` [PATCH net-next v3 1/4] tcp: initialize MTU probing before syncing MSS at connection setup Yongjian Wang via B4 Relay
2026-11-10  6:19   ` Kuniyuki Iwashima
2026-11-09 16:44 ` [PATCH net-next v3 2/4] selftests/net: packetdrill: test tcp_base_mss on passive connections Yongjian Wang via B4 Relay
2026-11-09 16:44 ` [PATCH net-next v3 3/4] selftests/net: packetdrill: add TCP black hole detection test Yongjian Wang via B4 Relay
2026-11-09 18:12   ` Neal Cardwell
2026-11-10 16:49     ` Esko Mobius [this message]
2026-11-09 16:44 ` [PATCH net-next v3 4/4] selftests/net: packetdrill: add TCP MTU probing test Yongjian Wang via B4 Relay

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=18B3E417-AC3D-4A70-88BD-4ADA9003ACAF@gmail.com \
    --to=echoowall@gmail.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@kernel.org \
    --cc=horms@kernel.org \
    --cc=kuba@kernel.org \
    --cc=kuniyu@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=ncardwell@google.com \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=panweiping3@gmail.com \
    --cc=shuah@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®