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Linus Torvalds 66bbe4a8ed Updates for the interrupt core subsystem:
- Remove the interrupt timing infrastructure
 
    This was added seven years ago to be used for power management purposes, but
    that integration never happened.
 
  - Clean up the remaining setup_percpu_irq() users
 
    The memory allocator is available when interrupts can be requested so there
    is not need for static irq_action. Move the remaining users to
    request_percpu_irq() and delete the historical cruft.
 
  - Warn when interrupt flag inconsistencies are detected in request*_irq().
 
    Inconsistent flags can lead to hard to diagnose malfunction. The fallout of
    this new warning has been addressed in next and the fixes are coming in via
    the maintainer trees and the tip irq/cleanup pull requests.
 
  - Invoke affinity notifier when CPU hotplug breaks affinity
 
    Otherwise the code using the notifier misses the affinity change and
    operates on stale information.
 
  - The usual cleanups and improvements
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Merge tag 'irq-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq core updates from Thomas Gleixner:
 "Updates for the interrupt core subsystem:

   - Remove the interrupt timing infrastructure

     This was added seven years ago to be used for power management
     purposes, but that integration never happened.

   - Clean up the remaining setup_percpu_irq() users

     The memory allocator is available when interrupts can be requested
     so there is not need for static irq_action. Move the remaining
     users to request_percpu_irq() and delete the historical cruft.

   - Warn when interrupt flag inconsistencies are detected in
     request*_irq().

     Inconsistent flags can lead to hard to diagnose malfunction. The
     fallout of this new warning has been addressed in next and the
     fixes are coming in via the maintainer trees and the tip
     irq/cleanup pull requests.

   - Invoke affinity notifier when CPU hotplug breaks affinity

     Otherwise the code using the notifier misses the affinity change
     and operates on stale information.

   - The usual cleanups and improvements"

* tag 'irq-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/proc: Replace snprintf with strscpy in register_handler_proc
  genirq/cpuhotplug: Notify about affinity changes breaking the affinity mask
  genirq: Move clear of kstat_irqs to free_desc()
  genirq: Warn about using IRQF_ONESHOT without a threaded handler
  irqdomain: Fix up const problem in irq_domain_set_name()
  genirq: Remove setup_percpu_irq()
  clocksource/drivers/mips-gic-timer: Move GIC timer to request_percpu_irq()
  MIPS: Move IP27 timer to request_percpu_irq()
  MIPS: Move IP30 timer to request_percpu_irq()
  genirq: Remove __request_percpu_irq() helper
  genirq: Remove IRQ timing tracking infrastructure
2026-02-10 13:39:37 -08:00
arch Updates for the interrupt core subsystem: 2026-02-10 13:39:37 -08:00
block The kthread code provides an infrastructure which manages the preferred 2026-02-09 19:57:30 -08:00
certs modsign: Enable ML-DSA module signing 2026-02-02 16:57:39 +00:00
crypto Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
Documentation x86/boot changes for v7.0: 2026-02-10 13:12:54 -08:00
drivers Updates for the interrupt core subsystem: 2026-02-10 13:39:37 -08:00
fs Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
include Updates for the interrupt core subsystem: 2026-02-10 13:39:37 -08:00
init Scheduler changes for v7.0: 2026-02-10 12:50:10 -08:00
io_uring for-7.0/block-20260206 2026-02-09 17:57:21 -08:00
ipc mqueue: switch to CLASS(filename) 2026-01-16 12:52:04 -05:00
kernel Updates for the interrupt core subsystem: 2026-02-10 13:39:37 -08:00
lib Updates for the interrupt core subsystem: 2026-02-10 13:39:37 -08:00
LICENSES LICENSES: Add modern form of the LGPL-2.1 tags to the usage guide section 2025-10-22 07:58:19 +02:00
mm Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
net Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
rust Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
samples samples: rust: remove imports available via prelude 2026-01-26 18:15:20 +01:00
scripts Scheduler changes for v7.0: 2026-02-10 12:50:10 -08:00
security Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
sound ALSA: hda/realtek: Enable headset mic for Acer Nitro 5 2026-02-05 09:05:10 +01:00
tools Scheduler changes for v7.0: 2026-02-10 12:50:10 -08:00
usr initramfs: add gen_init_cpio to hostprogs unconditionally 2025-11-26 21:55:40 +01:00
virt Performance events changes for v7.0: 2026-02-10 12:00:46 -08:00
.clang-format s390/pci: Fix cyclic dead-lock in zpci_zdev_put() and zpci_scan_devices() 2025-12-14 11:03:58 +01:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore rust: kbuild: add proc macro library support 2025-11-24 17:15:36 +01:00
.mailmap Rust changes for v6.20 / v7.0 2026-02-10 11:53:01 -08:00
.pylintrc docs: Move the python libraries to tools/lib/python 2025-11-18 09:22:40 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS A slightly calmer cycle for docs this time around, though there is still a 2026-02-09 20:53:18 -08:00
Kbuild sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
Makefile Locking updates for v6.20: 2026-02-10 12:28:44 -08:00
README docs: add AI Coding Assistants documentation 2026-01-06 14:55:06 -07:00

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
* AI Coding Assistant - LLMs and AI-powered development tools


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

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


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