tcp_ratelimit: provide an api for drivers to release ratesets at detach

When the kernel is compiled with options RATELIMIT, the
mlx5en driver cannot detach. It gets stuck waiting for all
kernel user

tcp_ratelimit: provide an api for drivers to release ratesets at detach

When the kernel is compiled with options RATELIMIT, the
mlx5en driver cannot detach. It gets stuck waiting for all
kernel users of its rates to drop to zero before finally calling
ether_ifdetach.

The tcp ratelimit code has an eventhandler for ifnet departure
which causes rates to be released. However, this is called as an
ifnet departure eventhandler, which is invoked as part of
ifdetach(), via either_ifdetach(). This means that the tcp
ratelimit code holds down many hw rates when the mlx5en driver
is waiting for the rate count to go to 0. Thus devctl detach
will deadlock on mlx5 with this stack:
mi_switch+0xcf sleepq_timedwait+0x2f _sleep+0x1a3 pause_sbt+0x77 mlx5e_destroy_ifp+0xaf mlx5_remove_device+0xa7 mlx5_unregister_device+0x78 mlx5_unload_one+0x10a remove_one+0x1e linux_pci_detach_device+0x36 linux_pci_detach+0x24 device_detach+0x180 devctl2_ioctl+0x3dc devfs_ioctl+0xbb vn_ioctl+0xca devfs_ioctl_f+0x1e kern_ioctl+0x1c3 sys_ioctl+0x10a

To fix this, provide an explicit API for a driver to call the tcp
ratelimit code telling it to detach itself from an ifnet. This
allows the mlx5 driver to unload cleanly. I considered adding an
ifnet pre-departure eventhandler. However, that would need to be
invoked by the driver, so a simple function call seemed better.

The mlx5en driver has been updated to call this function.

Reviewed by: kib, rrs

Differential Revision: https://reviews.freebsd.org/D46221
Sponsored by: Netflix

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tcp: Silence a -Wunused-function warning in tcp_ratelimit.h

No functional change intended.

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

rack and bbr not loading if TCP_RATELIMIT is not configured.

So it turns out that rack and bbr still will not load without TCP_RATELIMIT. This needs
to be fixed and lets also at the same time bring

rack and bbr not loading if TCP_RATELIMIT is not configured.

So it turns out that rack and bbr still will not load without TCP_RATELIMIT. This needs
to be fixed and lets also at the same time bring tcp_ratelimit up to date where we allow
the transports to set a divisor (though still having a default path with the default
divisor of 1000) for setting the burst size.

Reviewed by: tuexen, gallatin
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D37954

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This takes Warners suggested approach to making it so that
platforms that for whatever reason cannot include the RATELIMIT option
can still work with rack. It adds two dummy functions that rack will

This takes Warners suggested approach to making it so that
platforms that for whatever reason cannot include the RATELIMIT option
can still work with rack. It adds two dummy functions that rack will
call and find out that the highest hw supported b/w is 0 (which
kinda makes sense and rack is already prepared to handle).

Reviewed by: Michael Tuexen, Warner Losh
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D30163

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This brings into sync FreeBSD with the netflix versions of rack and bbr.
This fixes several breakages (panics) since the tcp_lro code was
committed that have been reported. Quite a few new features a

This brings into sync FreeBSD with the netflix versions of rack and bbr.
This fixes several breakages (panics) since the tcp_lro code was
committed that have been reported. Quite a few new features are
now in rack (prefecting of DGP -- Dynamic Goodput Pacing among the
largest). There is also support for ack-war prevention. Documents
comming soon on rack..

Sponsored by: Netflix
Reviewed by: rscheff, mtuexen
Differential Revision: https://reviews.freebsd.org/D30036

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Fix LINT kernel builds after 1a714ff20419 .

MFC after: 1 week
Discussed with: rrs@
Differential Revision: https://reviews.freebsd.org/D28357
Sponsored by: Mellanox Technologies // NVIDIA Networking

This pulls over all the changes that are in the netflix
tree that fix the ratelimit code. There were several bugs
in tcp_ratelimit itself and we needed further work to support
the multiple tag format

This pulls over all the changes that are in the netflix
tree that fix the ratelimit code. There were several bugs
in tcp_ratelimit itself and we needed further work to support
the multiple tag format coming for the joint TLS and Ratelimit dances.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D28357

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Fix copyright year and eliminate the obsolete all rights reserved line.

Reviewed by: rrs@

Merge ^/head r358269 through r358399.

This commit expands tcp_ratelimit to be able to handle cards
like the mlx-c5 and c6 that require a "setup" routine before
the tcp_ratelimit code can declare and use a rate. I add the
setup routine to

This commit expands tcp_ratelimit to be able to handle cards
like the mlx-c5 and c6 that require a "setup" routine before
the tcp_ratelimit code can declare and use a rate. I add the
setup routine to if_var as well as fix tcp_ratelimit to call it.
I also revisit the rates so that in the case of a mlx card
of type c5/6 we will use about 100 rates concentrated in the range
where the most gain can be had (1-200Mbps). Note that I have
tested these on a c5 and they work and perform well. In fact
in an unloaded system they pace right to the correct rate (great
job mlx!). There will be a further commit here from Hans that
will add the respective changes to the mlx driver to support this
work (which I was testing with).

Sponsored by: Netflix Inc.
Differential Revision: ttps://reviews.freebsd.org/D23647

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Opps committed the wrong ratelimit version in the
whitespace cleanup.. Restore it to the proper version.

Sponsored by: Netfilx Inc.

White space cleanup -- remove trailing tab's or spaces
from any line.

Sponsored by: Netflix Inc.

Merge ^/head r352587 through r352763.

Fix the ifdefs in tcp_ratelimit.h. They were reversed so
that instead of functions only being inside the _KERNEL and
the absence of RATELIMIT causing us to have NULL/error returning
interfaces we end

Fix the ifdefs in tcp_ratelimit.h. They were reversed so
that instead of functions only being inside the _KERNEL and
the absence of RATELIMIT causing us to have NULL/error returning
interfaces we ended up with non-kernel getting the error path.
opps..

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This adds the third step in getting BBR into the tree. BBR and
an updated rack depend on having access to the new
ratelimit api in this commit.

Sponsored by: Netflix Inc.
Differential Revision: http

This adds the third step in getting BBR into the tree. BBR and
an updated rack depend on having access to the new
ratelimit api in this commit.

Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D20953

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