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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Simon Barber <simon@superduper.net>
Cc: Hal Murray <hmurray@megapathdsl.net>,
	bloat <bloat@lists.bufferbloat.net>
Subject: Re: [Bloat] SO_SNDBUF and SO_RCVBUF
Date: Wed, 22 Apr 2015 16:08:33 -0700	[thread overview]
Message-ID: <1429744113.18561.169.camel@edumazet-glaptop2.roam.corp.google.com> (raw)
In-Reply-To: <14ce337d3c8.27f7.e972a4f4d859b00521b2b659602cb2f9@superduper.net>

On Wed, 2015-04-22 at 15:20 -0700, Simon Barber wrote:
> Wouldn't the LOWAT setting be much easier for applications to use if it was 
> set in estimated time (ie time it will take to deliver the data) rather 
> than bytes?

Sure, but you have all the info to infer one from the other.

Note also TCP stack has immediate notion of bytes, while adding time
delays immediately impose a possibly expensive time acquisition in high
precision.

# git show c9bee3b7fdecb0c1d070c7b54113b3bdfb9a3d36 | diffstat -p1 -w70
 Documentation/networking/ip-sysctl.txt |   13 +++++++++++++
 include/linux/tcp.h                    |    1 +
 include/net/sock.h                     |   19 +++++++++++++------
 include/net/tcp.h                      |   14 ++++++++++++++
 include/uapi/linux/tcp.h               |    1 +
 net/ipv4/sysctl_net_ipv4.c             |    7 +++++++
 net/ipv4/tcp.c                         |    7 +++++++
 net/ipv4/tcp_ipv4.c                    |    1 +
 net/ipv4/tcp_output.c                  |    3 +++
 net/ipv6/tcp_ipv6.c                    |    1 +
 10 files changed, 61 insertions(+), 6 deletions(-)

A time based implementation would be way more complex/expensive.



  reply	other threads:[~2015-04-22 23:08 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 [this message]
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

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