MFC r300779, r300781, r300783, r300784, r300949, r301162, r301180

MFC r300779, r300781, r300783, r300784, r300949, r301162, r301180

r300779 | truckman | 2016-05-26 14:40:13 -0700 (Thu, 26 May 2016) | 64 lines

Import Dummynet AQM version 0.2.1 (CoDel, FQ-CoDel, PIE and FQ-PIE).

Centre for Advanced Internet Architectures

Implementing AQM in FreeBSD

* Overview <http://caia.swin.edu.au/freebsd/aqm/index.html>

* Articles, Papers and Presentations
  <http://caia.swin.edu.au/freebsd/aqm/papers.html>

* Patches and Tools <http://caia.swin.edu.au/freebsd/aqm/downloads.html>

Overview

Recent years have seen a resurgence of interest in better managing
the depth of bottleneck queues in routers, switches and other places
that get congested. Solutions include transport protocol enhancements
at the end-hosts (such as delay-based or hybrid congestion control
schemes) and active queue management (AQM) schemes applied within
bottleneck queues.

The notion of AQM has been around since at least the late 1990s
(e.g. RFC 2309). In recent years the proliferation of oversized
buffers in all sorts of network devices (aka bufferbloat) has
stimulated keen community interest in four new AQM schemes -- CoDel,
FQ-CoDel, PIE and FQ-PIE.

The IETF AQM working group is looking to document these schemes,
and independent implementations are a corner-stone of the IETF's
process for confirming the clarity of publicly available protocol
descriptions. While significant development work on all three schemes
has occured in the Linux kernel, there is very little in FreeBSD.

Project Goals

This project began in late 2015, and aims to design and implement
functionally-correct versions of CoDel, FQ-CoDel, PIE and FQ_PIE
in FreeBSD (with code BSD-licensed as much as practical). We have
chosen to do this as extensions to FreeBSD's ipfw/dummynet firewall
and traffic shaper. Implementation of these AQM schemes in FreeBSD
will:
* Demonstrate whether the publicly available documentation is
  sufficient to enable independent, functionally equivalent implementations

* Provide a broader suite of AQM options for sections the networking
  community that rely on FreeBSD platforms

Program Members:

* Rasool Al Saadi (developer)

* Grenville Armitage (project lead)

Acknowledgements:

This project has been made possible in part by a gift from the
Comcast Innovation Fund.

Submitted by:	Rasool Al-Saadi <ralsaadi@swin.edu.au>
X-No objection:	core
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D6388

[Remove some code that was added to the mq_append() inline function in
HEAD by r258457, which was not merged to stable/10.  The AQM patch
moved mq_append() from ip_dn_io.c to the new file ip_dn_private.h, so
we need to remove that copy of the r258457 changes.]
------------------------------------------------------------------------
r300781 | truckman | 2016-05-26 14:44:52 -0700 (Thu, 26 May 2016) | 7 lines

Modify BOUND_VAR() macro to wrap all of its arguments in () and tweak
its expression to work on powerpc and sparc64 (gcc compatibility).

Correct a typo in a nearby comment.

MFC after:	2 weeks (with r300779)

------------------------------------------------------------------------
r300783 | truckman | 2016-05-26 15:03:28 -0700 (Thu, 26 May 2016) | 4 lines

Correct a typo in a comment.

MFC after:	2 weeks (with r300779)

------------------------------------------------------------------------
r300784 | truckman | 2016-05-26 15:07:09 -0700 (Thu, 26 May 2016) | 5 lines

Include the new AQM files when compiling a kernel with options DUMMYNET.

Reported by:	Nikolay Denev <nike_d AT cytexbg DOT com>
MFC after:	2 weeks (with r300779)

------------------------------------------------------------------------
r300949 | truckman | 2016-05-29 00:23:56 -0700 (Sun, 29 May 2016) | 10 lines

Cast some expressions that multiply a long long constant by a
floating point constant to int64_t.  This avoids the runtime
conversion of the the other operand in a set of comparisons from
int64_t to floating point and doing the comparisions in floating
point.

Suggested by:	lidl
Submitted by:	Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after:	2 weeks (with r300779)

------------------------------------------------------------------------
r301162 | truckman | 2016-06-01 13:04:24 -0700 (Wed, 01 Jun 2016) | 9 lines

Replace constant expressions that contain multiplications by
fractional floating point values with integer divides.  This will
eliminate any chance that the compiler will generate code to evaluate
the expression using floating point at runtime.

Suggested by:	bde
Submitted by:	Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after:	8 days (with r300779 and r300949)

------------------------------------------------------------------------
r301180 | truckman | 2016-06-01 17:42:15 -0700 (Wed, 01 Jun 2016) | 2 lines

Belatedly bump .Dd date for Dummynet AQM import in r300779.

Relnotes:	yes

git-svn-id: svn://svn.freebsd.org/base/stable/10@301772 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f