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Jakub Kicinski 92346bde96 Merge branch 'add-tc-taprio-support-for-queuemaxsdu'
Vladimir Oltean says:

====================
Add tc-taprio support for queueMaxSDU

The tc-taprio offload mode supported by the Felix DSA driver has
limitations surrounding its guard bands.

The initial discussion was at:
https://lore.kernel.org/netdev/c7618025da6723418c56a54fe4683bd7@walle.cc/

with the latest status being that we now have a vsc9959_tas_guard_bands_update()
method which makes a best-guess attempt at how much useful space to
reserve for packet scheduling in a taprio interval, and how much to
reserve for guard bands.

IEEE 802.1Q actually does offer a tunable variable (queueMaxSDU) which
can determine the max MTU supported per traffic class. In turn we can
determine the size we need for the guard bands, depending on the
queueMaxSDU. This way we can make the guard band of small taprio
intervals smaller than one full MTU worth of transmission time, if we
know that said traffic class will transport only smaller packets.

As discussed with Gerhard Engleder, the queueMaxSDU may also be useful
in limiting the latency on an endpoint, if some of the TX queues are
outside of the control of the Linux driver.
https://patchwork.kernel.org/project/netdevbpf/patch/20220914153303.1792444-11-vladimir.oltean@nxp.com/

Allow input of queueMaxSDU through netlink into tc-taprio, offload it to
the hardware I have access to (LS1028A), and (implicitly) deny
non-default values to everyone else. Kurt Kanzenbach has also kindly
tested and shared a patch to offload this to hellcreek.

v3 at:
https://patchwork.kernel.org/project/netdevbpf/cover/20220927234746.1823648-1-vladimir.oltean@nxp.com/
v2 at:
https://patchwork.kernel.org/project/netdevbpf/list/?series=679954&state=*
v1 at:
https://patchwork.kernel.org/project/netdevbpf/cover/20220914153303.1792444-1-vladimir.oltean@nxp.com/
====================

Link: https://lore.kernel.org/r/20220928095204.2093716-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29 18:52:07 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
block block-6.0-2022-09-22 2022-09-24 08:22:53 -07:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation dt-bindings: net: snps,dwmac: Document stmmac-axi-config subnode 2022-09-29 18:43:51 -07:00
drivers net: enetc: offload per-tc max SDU from tc-taprio 2022-09-29 18:52:06 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
include net/sched: taprio: allow user input of per-tc max SDU 2022-09-29 18:52:05 -07:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring io_uring-6.0-2022-09-23 2022-09-24 08:27:08 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm 26 hotfixes. 8 are for issues which were introduced during this -rc 2022-09-26 13:23:15 -07:00
net net/sched: taprio: allow user input of per-tc max SDU 2022-09-29 18:52:05 -07:00
samples samples/bpf: Reduce syscall overhead in map_perf_test. 2022-09-05 15:33:05 +02:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
security Landlock fix for v6.0-rc4 2022-09-02 15:24:08 -07:00
sound ALSA: hda: intel-dsp-config: add missing RaptorLake PCI IDs 2022-09-22 13:50:33 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device() 2022-08-19 04:05:43 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap Qualcomm ARM64 DTS fixes for 6.0 2022-09-23 16:44:37 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-29 14:30:51 -07:00
Makefile Linux 6.0-rc7 2022-09-25 14:01:02 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.