From: Eric Dumazet <erdnetdev@gmail.com>
To: Yuchung Cheng <ycheng@google.com>
Cc: davem@davemloft.net, ncardwell@google.com, edumazet@google.com,
nanditad@google.com, ilpo.jarvinen@cs.helsinki.fi,
netdev@vger.kernel.org
Subject: Re: [PATCH v2 1/3 net-next] tcp: refactor F-RTO
Date: Wed, 20 Mar 2013 16:55:06 -0700 [thread overview]
Message-ID: <1363823706.3333.31.camel@edumazet-glaptop> (raw)
In-Reply-To: <1363822380-16687-1-git-send-email-ycheng@google.com>
On Wed, 2013-03-20 at 16:32 -0700, Yuchung Cheng wrote:
> The patch series refactor the F-RTO feature (RFC4138/5682).
>
> This is to simplify the loss recovery processing. Existing F-RTO
> was developed during the experimental stage (RFC4138) and has
> many experimental features. It takes a separate code path from
> the traditional timeout processing by overloading CA_Disorder
> instead of using CA_Loss state. This complicates CA_Disorder state
> handling because it's also used for handling dubious ACKs and undos.
> While the algorithm in the RFC does not change the congestion control,
> the implementation intercepts congestion control in various places
> (e.g., frto_cwnd in tcp_ack()).
>
> The new code implements newer F-RTO RFC5682 using CA_Loss processing
> path. F-RTO becomes a small extension in the timeout processing
> and interfaces with congestion control and Eifel undo modules.
> It lets congestion control (module) determines how many to send
> independently. F-RTO only chooses what to send in order to detect
> spurious retranmission. If timeout is found spurious it invokes
> existing Eifel undo algorithms like DSACK or TCP timestamp based
> detection.
>
> The first patch removes all F-RTO code except the sysctl_tcp_frto is
> left for the new implementation. Since CA_EVENT_FRTO is removed, TCP
> westwood now computes ssthresh on regular timeout CA_EVENT_LOSS event.
>
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
> Acked-by: Neal Cardwell <ncardwell@google.com>
> ---
Acked-by: Eric Dumazet <edumazet@google.com>
next prev parent reply other threads:[~2013-03-21 0:01 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-20 23:32 [PATCH v2 1/3 net-next] tcp: refactor F-RTO Yuchung Cheng
2013-03-20 23:32 ` [PATCH v2 2/3 net-next] tcp: refactor CA_Loss state processing Yuchung Cheng
2013-03-20 23:56 ` Eric Dumazet
2013-03-20 23:33 ` [PATCH v2 3/3 net-next] tcp: implement RFC5682 F-RTO Yuchung Cheng
2013-03-21 5:00 ` Eric Dumazet
2013-03-21 13:26 ` Neal Cardwell
2013-03-20 23:55 ` Eric Dumazet [this message]
2013-03-21 15:48 ` [PATCH v2 1/3 net-next] tcp: refactor F-RTO David Miller
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=1363823706.3333.31.camel@edumazet-glaptop \
--to=erdnetdev@gmail.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=ilpo.jarvinen@cs.helsinki.fi \
--cc=nanditad@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