Update to bring the rack stack with all its fixes in.

This brings the rack stack up to the current level used at NF. Many fixes
and improvements have been added. I also add in a fix to BBR to deal w

Update to bring the rack stack with all its fixes in.

This brings the rack stack up to the current level used at NF. Many fixes
and improvements have been added. I also add in a fix to BBR to deal with
the changes that have been in hpts for a while i.e. only one call no matter
if mbuf queue or tcp_output.

It basically does little except BBlogs and is a placemark for future work on
doing path capacity measurements.

With a bit of a struggle with git I finally got rack_pcm.c into place (apologies
for not noticing this error). The LINT kernel is running on my box now .. sigh.

Reviewed by: tuexen, glebius
Sponsored by: Netflix Inc.
Differential Revision:https://reviews.freebsd.org/D43986

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Revert "Update to bring the rack stack with all its fixes in."

This commit was incomplete and breaks LINT kernels. The tree has been
broken for 8+ hours.

This reverts commit f6d489f402c320f1a6eaa4

Revert "Update to bring the rack stack with all its fixes in."

This commit was incomplete and breaks LINT kernels. The tree has been
broken for 8+ hours.

This reverts commit f6d489f402c320f1a6eaa473491a0b8c3878113e.

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Update to bring the rack stack with all its fixes in.

This brings the rack stack up to the current level used at NF. Many fixes
and improvements have been added. I also add in a fix to BBR to deal w

Update to bring the rack stack with all its fixes in.

This brings the rack stack up to the current level used at NF. Many fixes
and improvements have been added. I also add in a fix to BBR to deal with
the changes that have been in hpts for a while i.e. only one call no matter
if mbuf queue or tcp_output.

Note there is a new file that I can't figure out how to get in rack_pcm.c

It basically does little except BBlogs and is a placemark for future work on
doing path capacity measurements.

Reviewed by: tuexen, glebius
Sponsored by: Netflix Inc.
Differential Revision:https://reviews.freebsd.org/D43986

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sys: Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Update rack to the latest code used at NF.

There have been many changes to rack over the last couple of years, including:
a) Ability when switching stacks to have one stack query another.

Update rack to the latest code used at NF.

There have been many changes to rack over the last couple of years, including:
a) Ability when switching stacks to have one stack query another.
b) Internal use of micro-second timers instead of ticks.
c) Many changes to pacing in forms of
1) Improvements to Dynamic Goodput Pacing (DGP)
2) Improvements to fixed rate paciing
3) A new feature called hybrid pacing where the requestor can
get a combination of DGP and fixed rate pacing with deadlines
for delivery that can dynamically speed things up.
d) All kinds of bugs found during extensive testing and use of the
rack stack for streaming video and in fact all data transferred
by NF

Reviewed by: glebius, gallatin, tuexen
Sponsored By: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D39402

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Fixes in the tcp infrastructure with respect to stack changes as well as other infrastructure updates for incoming rack features.

So stack switching as always been a bit of a issue. We currently use

Fixes in the tcp infrastructure with respect to stack changes as well as other infrastructure updates for incoming rack features.

So stack switching as always been a bit of a issue. We currently use a break before make setup which means that
if something goes wrong you have to try to get back to a stack. This patch among a lot of other things changes that so
that it is a make before break. We also expand some of the function blocks in prep for new features in rack that will allow
more controlled pacing. We also add other abilities such as the pathway for a stack to query a previous stack to acquire from
it critical state information so things in flight don't get dropped or mis-handled when switching stacks. We also add the
concept of a timer granularity. This allows an alternate stack to change from the old ticks granularity to microseconds and
of course this even gives us a pathway to go to nanosecond timekeeping if we need to (something for the data center to consider
for sure).

Once all this lands I will then update rack to begin using all these new features.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D39210

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tcp: retire TCPDEBUG

This subsystem is superseded by modern debugging facilities,
e.g. DTrace probes and TCP black box logging.

We intentionally leave SO_DEBUG in place, as many utilities may
set i

tcp: retire TCPDEBUG

This subsystem is superseded by modern debugging facilities,
e.g. DTrace probes and TCP black box logging.

We intentionally leave SO_DEBUG in place, as many utilities may
set it on a socket. Also the tcp::debug DTrace probes look at
this flag on a socket.

Reviewed by: gnn, tuexen
Discussed with: rscheff, rrs, jtl
Differential revision: https://reviews.freebsd.org/D37694

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rack/bbr: fix standalone kernel module build

MFHead @r350386

Sponsored by: The FreeBSD Foundation

This commit updates rack to what is basically being used at NF as
well as sets in some of the groundwork for committing BBR. The
hpts system is updated as well as some other needed utilities
for the

This commit updates rack to what is basically being used at NF as
well as sets in some of the groundwork for committing BBR. The
hpts system is updated as well as some other needed utilities
for the entrance of BBR. This is actually part 1 of 3 more
needed commits which will finally complete with BBRv1 being
added as a new tcp stack.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D20834

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Take out the stack alias inadvertantly added by my commit.

Reported by: Peter Lei

This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent ackno

This commit brings in a new refactored TCP stack called Rack.
Rack includes the following features:
- A different SACK processing scheme (the old sack structures are not used).
- RACK (Recent acknowledgment) where counting dup-acks is no longer done
instead time is used to knwo when to retransmit. (see the I-D)
- TLP (Tail Loss Probe) where we will probe for tail-losses to attempt
to try not to take a retransmit time-out. (see the I-D)
- Burst mitigation using TCPHTPS
- PRR (partial rate reduction) see the RFC.

Once built into your kernel, you can select this stack by either
socket option with the name of the stack is "rack" or by setting
the global sysctl so the default is rack.

Note that any connection that does not support SACK will be kicked
back to the "default" base FreeBSD stack (currently known as "default").

To build this into your kernel you will need to enable in your
kernel:
makeoptions WITH_EXTRA_TCP_STACKS=1
options TCPHPTS

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D15525

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