From: David Miller <davem@davemloft.net>
To: ncardwell@google.com
Cc: netdev@vger.kernel.org, ycheng@google.com, edumazet@google.com
Subject: Re: [PATCH net] tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP
Date: Fri, 18 Aug 2017 16:08:20 -0700 (PDT) [thread overview]
Message-ID: <20170818.160820.1134182631606956474.davem@davemloft.net> (raw)
In-Reply-To: <20170816215336.30419-1-ncardwell@google.com>
From: Neal Cardwell <ncardwell@google.com>
Date: Wed, 16 Aug 2017 17:53:36 -0400
> In some situations tcp_send_loss_probe() can realize that it's unable
> to send a loss probe (TLP), and falls back to calling tcp_rearm_rto()
> to schedule an RTO timer. In such cases, sometimes tcp_rearm_rto()
> realizes that the RTO was eligible to fire immediately or at some
> point in the past (delta_us <= 0). Previously in such cases
> tcp_rearm_rto() was scheduling such "overdue" RTOs to happen at now +
> icsk_rto, which caused needless delays of hundreds of milliseconds
> (and non-linear behavior that made reproducible testing
> difficult). This commit changes the logic to schedule "overdue" RTOs
> ASAP, rather than at now + icsk_rto.
>
> Suggested-by: Yuchung Cheng <ycheng@google.com>
> Signed-off-by: Neal Cardwell <ncardwell@google.com>
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
Applied with Fixes: tag added and queued up for -stable, thanks Neal.
prev parent reply other threads:[~2017-08-18 23:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-16 21:53 [PATCH net] tcp: when rearming RTO, if RTO time is in past then fire RTO ASAP Neal Cardwell
2017-08-17 14:56 ` Neal Cardwell
2017-08-18 23:08 ` 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=20170818.160820.1134182631606956474.davem@davemloft.net \
--to=davem@davemloft.net \
--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).