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Gerd Rausch a1f53d5fb6 net/rds: Use the first lane until RDS_EXTHDR_NPATHS arrives
Instead of just blocking the sender until "c_npaths" is known
(it gets updated upon the receipt of a MPRDS PONG message),
simply use the first lane (cp_index#0).

But just using the first lane isn't enough.

As soon as we enqueue messages on a different lane, we'd run the risk
of out-of-order delivery of RDS messages.

Earlier messages enqueued on "cp_index == 0" could be delivered later
than more recent messages enqueued on "cp_index > 0", mostly because of
possible head of line blocking issues causing the first lane to be
slower.

To avoid that, we simply take a snapshot of "cp_next_tx_seq" at the
time we're about to fan-out to more lanes.

Then we delay the transmission of messages enqueued on other lanes
with "cp_index > 0" until cp_index#0 caught up with the delivery of
new messages (from "cp_send_queue") as well as in-flight
messages (from "cp_retrans") that haven't been acknowledged yet
by the receiver.

We also add a new counter "mprds_catchup_tx0_retries" to keep track
of how many times "rds_send_xmit" had to suspend activities,
because it was waiting for the first lane to catch up.

Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20260203055723.1085751-8-achender@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-04 20:46:39 -08:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-01-29 17:28:54 -08:00
block block-6.19-20260122 2026-01-23 12:53:56 -08:00
certs
crypto
Documentation Some more changes, including pulls from drivers: 2026-02-04 20:31:05 -08:00
drivers ovpn: Replace use of system_wq with system_percpu_wq 2026-02-04 20:41:38 -08:00
fs for-6.19-rc7-tag 2026-01-29 09:07:17 -08:00
include net/iucv: clean up iucv kernel-doc warnings 2026-02-04 20:39:58 -08:00
init
io_uring io_uring-6.19-20260122 2026-01-23 12:51:00 -08:00
ipc
kernel tracing fixes for v6.19: 2026-01-24 17:18:57 -08:00
lib lib/crypto: sha1: Remove low-level functions from API 2026-01-27 15:47:41 -08:00
LICENSES
mm
net net/rds: Use the first lane until RDS_EXTHDR_NPATHS arrives 2026-02-04 20:46:39 -08:00
rust Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2026-01-29 17:28:54 -08:00
samples
scripts tracing fixes for v6.19: 2026-01-24 17:18:57 -08:00
security keys/trusted_keys: fix handle passed to tpm_buf_append_name during unseal 2026-01-25 19:03:45 +02:00
sound ALSA: hda/realtek: ALC269 fixup for Lenovo Yoga Book 9i 13IRU8 audio 2026-01-22 13:33:41 +01:00
tools selftests: mptcp: join: no SKIP mark for group checks 2026-02-04 18:45:34 -08:00
usr
virt
.clang-format
.clippy.toml
.cocciconfig
.editorconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
.pylintrc
.rustfmt.toml
COPYING
CREDITS net: ethernet: neterion: s2io: remove unused driver 2026-01-28 20:08:07 -08:00
Kbuild
Kconfig
MAINTAINERS dt-bindings: ptp: Add amazon,vmclock 2026-02-02 18:06:00 -08:00
Makefile Linux 6.19-rc7 2026-01-25 14:11:24 -08:00
README

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

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst



Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst