From: David Miller <davem@davemloft.net>
To: ncardwell@google.com
Cc: netdev@vger.kernel.org, ycheng@google.com,
octavian.purdila@intel.com, hkchu@google.com
Subject: Re: [PATCH net-next] tcp: switch snt_synack back to measuring transmit time of first SYNACK
Date: Mon, 07 Jul 2014 19:26:52 -0700 (PDT) [thread overview]
Message-ID: <20140707.192652.2078847253054450980.davem@davemloft.net> (raw)
In-Reply-To: <1404155389-22927-1-git-send-email-ncardwell@google.com>
From: Neal Cardwell <ncardwell@google.com>
Date: Mon, 30 Jun 2014 15:09:49 -0400
> Always store in snt_synack the time at which the server received the
> first client SYN and attempted to send the first SYNACK.
>
> Recent commit aa27fc501 ("tcp: tcp_v[46]_conn_request: fix snt_synack
> initialization") resolved an inconsistency between IPv4 and IPv6 in
> the initialization of snt_synack. This commit brings back the idea
> from 843f4a55e (tcp: use tcp_v4_send_synack on first SYN-ACK), which
> was going for the original behavior of snt_synack from the commit
> where it was added in 9ad7c049f0f79 ("tcp: RFC2988bis + taking RTT
> sample from 3WHS for the passive open side") in v3.1.
>
> In addition to being simpler (and probably a tiny bit faster),
> unconditionally storing the time of the first SYNACK attempt has been
> useful because it allows calculating a performance metric quantifying
> how long it took to establish a passive TCP connection.
>
> Signed-off-by: Neal Cardwell <ncardwell@google.com>
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
Applied, thanks.
prev parent reply other threads:[~2014-07-08 2:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-30 19:09 [PATCH net-next] tcp: switch snt_synack back to measuring transmit time of first SYNACK Neal Cardwell
2014-07-01 8:33 ` Octavian Purdila
2014-07-08 2:26 ` 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=20140707.192652.2078847253054450980.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=hkchu@google.com \
--cc=ncardwell@google.com \
--cc=netdev@vger.kernel.org \
--cc=octavian.purdila@intel.com \
--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).