From: David Miller <davem@davemloft.net>
To: ycheng@google.com
Cc: ncardwell@google.com, edumazet@google.com, brakmo@google.com,
netdev@vger.kernel.org
Subject: Re: [PATCH net] tcp: do not rearm RTO when future data are sacked
Date: Sun, 27 Oct 2013 16:52:05 -0400 (EDT) [thread overview]
Message-ID: <20131027.165205.2096790124067371223.davem@davemloft.net> (raw)
In-Reply-To: <1382630367-21964-1-git-send-email-ycheng@google.com>
From: Yuchung Cheng <ycheng@google.com>
Date: Thu, 24 Oct 2013 08:59:27 -0700
> Patch ed08495c3 "tcp: use RTT from SACK for RTO" always re-arms RTO upon
> obtaining a RTT sample from newly sacked data.
>
> But technically RTO should only be re-armed when the data sent before
> the last (re)transmission of write queue head are (s)acked. Otherwise
> the RTO may continue to extend during loss recovery on data sent
> in the future.
>
> Note that RTTs from ACK or timestamps do not have this problem, as the RTT
> source must be from data sent before.
>
> The new RTO re-arm policy is
> 1) Always re-arm RTO if SND.UNA is advanced
> 2) Re-arm RTO if sack RTT is available, provided the sacked data was
> sent before the last time write_queue_head was sent.
>
> Signed-off-by: Larry Brakmo <brakmo@google.com>
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
Also applied and queued up for -stable, thanks!
prev parent reply other threads:[~2013-10-27 20:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-24 15:59 [PATCH net] tcp: do not rearm RTO when future data are sacked Yuchung Cheng
2013-10-24 17:03 ` Neal Cardwell
2013-10-24 19:58 ` Eric Dumazet
2013-10-27 20:52 ` David Miller [this message]
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=20131027.165205.2096790124067371223.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=brakmo@google.com \
--cc=edumazet@google.com \
--cc=ncardwell@google.com \
--cc=netdev@vger.kernel.org \
--cc=ycheng@google.com \
/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;
as well as URLs for NNTP newsgroup(s).