From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hal Murray <hmurray@megapathdsl.net>,
bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] SO_SNDBUF and SO_RCVBUF
Date: Thu, 23 Apr 2015 00:11:54 +0200 [thread overview]
Message-ID: <20150422221154.GB31348@sesse.net> (raw)
In-Reply-To: <1429738979.18561.150.camel@edumazet-glaptop2.roam.corp.google.com>
On Wed, Apr 22, 2015 at 02:42:59PM -0700, Eric Dumazet wrote:
> Sorry, I do not understand you.
>
> The nice thing about TCP_NOTSENT_LOWAT is that you no longer have to
> care about choosing the 'right SO_SNDBUF'
>
> It is still CC responsibility to choose/set cwnd, but you hadn't set an
> artificial cap on cwnd.
>
> You control the amount of 'unsent data' per socket.
>
> If you set a low limit, application might have to issue more send()
> calls and get more EPOLLOUT events.
>
> This also means that if you get an abort / eof, you no longer have a
> huge unsent queue that TCP API does not allow to cancel.
>
> https://insouciant.org/tech/prioritization-only-works-when-theres-pending-data-to-prioritize/
So this URL is basically what I said; you need to have data to prioritize
between for this to be useful. If you just want to send a simple file
(and aborts in HTTP/1.1 basically don't really exist), it doesn't really
matter if you have a huge backlog or not.
So I'm sure it's useful for HTTP/2 or SPDY, but that's already pretty
advanced functionality.
/* Steinar */
--
Homepage: http://www.sesse.net/
prev parent reply other threads:[~2015-04-22 22:12 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-22 19:10 Hal Murray
2015-04-22 19:26 ` Rick Jones
2015-04-22 19:28 ` Dave Taht
2015-04-22 21:02 ` Eric Dumazet
2015-04-22 21:05 ` Rick Jones
2015-04-22 21:46 ` Eric Dumazet
2015-04-22 22:20 ` Simon Barber
2015-04-22 23:08 ` Eric Dumazet
2015-04-24 4:37 ` Dave Taht
2015-04-24 4:40 ` Dave Taht
2015-04-24 13:50 ` Eric Dumazet
2015-04-24 14:34 ` Dave Taht
2015-04-24 16:31 ` Rick Jones
2015-04-24 18:41 ` Eric Dumazet
2015-04-24 5:23 ` Eric Dumazet
2015-04-22 21:07 ` Steinar H. Gunderson
2015-04-22 21:42 ` Eric Dumazet
2015-04-22 21:47 ` Dave Taht
2015-04-22 22:11 ` Steinar H. Gunderson [this message]
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