All of lore.kernel.org
 help / color / mirror / Atom feed
From: Fan Du <fengyuleidian0615@gmail.com>
To: John Heffner <johnwheffner@gmail.com>
Cc: Fan Du <fan.du@intel.com>, Eric Dumazet <edumazet@google.com>,
	David Miller <davem@davemloft.net>,
	Netdev <netdev@vger.kernel.org>
Subject: Re: [PATCHv4 net-next 2/3] ipv4: Use binary search to choose tcp PMTU probe_size
Date: Thu, 05 Mar 2015 10:36:54 +0800	[thread overview]
Message-ID: <54F7C146.603@gmail.com> (raw)
In-Reply-To: <CABrhC0kTmdv7TJUFo88HjGgzLmm1p4_XRnuQZUoaOGh8DwmhVw@mail.gmail.com>

于 2015年03月04日 21:39, John Heffner 写道:
>> >I suspect there's plenty of room for further improvement in the
>> >probing heuristic, but this seems like a reasonable improvement.
>> >
>> >Acked-by: John Heffner<johnwheffner@gmail.com>
> Actually, one final suggestion here.  The cost of a failed probe is
> much higher than a successful probe.  I'd suggest still bounding the
> probe segment size to no more than 2*cur_mss.  (Think of a common case
> where mss_clamp = 9000 - headers, but the actual path MTU = 1500.)

huh...
Are you serious about clamping probe size to no more than 2*current_mss?
What about the opposite scenario where path MTU enlarges, e.g., current_mss
is nearing search_low?

I will make next version incorporating:
a. Update ip-sysctl.txt
b. Zero probe_size before reset search_low/high


>    -John

  reply	other threads:[~2015-03-05  2:41 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-03  9:19 [PATCHv4 net-next 0/3] Improvements for TCP PMTU Fan Du
2015-03-03  9:19 ` [PATCHv4 net-next 1/3] ipv4: Raise tcp PMTU probe mss base size Fan Du
2015-03-03 16:52   ` John Heffner
2015-03-03  9:19 ` [PATCHv4 net-next 2/3] ipv4: Use binary search to choose tcp PMTU probe_size Fan Du
2015-03-03 16:51   ` John Heffner
2015-03-04 13:39     ` John Heffner
2015-03-05  2:36       ` Fan Du [this message]
2015-03-03  9:19 ` [PATCHv4 net-next 3/3] ipv4: Create probe timer for tcp PMTU as per RFC4821 Fan Du
2015-03-03 16:39   ` John Heffner
2015-03-04  2:11     ` Fan Du
2015-03-04 13:26       ` John Heffner
2015-03-05  2:36         ` Fan Du
2015-03-03 16:43 ` [PATCHv4 net-next 0/3] Improvements for TCP PMTU John Heffner
2015-03-04  2:12   ` Fan Du

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=54F7C146.603@gmail.com \
    --to=fengyuleidian0615@gmail.com \
    --cc=davem@davemloft.net \
    --cc=edumazet@google.com \
    --cc=fan.du@intel.com \
    --cc=johnwheffner@gmail.com \
    --cc=netdev@vger.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.