Linux kernel source tree
Go to file
Linus Torvalds 5504ce0317 Power management updates for 7.2-rc1
- Fix a race between cpufreq suspend and CPU hotplug during system
    shutdown (Tianxiang Chen)
 
  - Avoid redundant target() calls for unchanged limits and fix a typo
    in a comment in the cpufreq core (Viresh Kumar)
 
  - Fix concurrency issues related to sysfs attributes access that affect
    cpufreq governors using the common governor code (Zhongqiu Han)
 
  - Simplify frequency limit handling in the conservative cpufreq
    governor (Lifeng Zheng)
 
  - Fix descriptions of the conservative governor freq_step tunable and
    the ondemand governor sampling_down_factor tunable in the cpufreq
    documentation (Pengjie Zhang)
 
  - Fix use-after-free and double free during _OSC evaluation in the PCC
    cpufreq driver (Yuho Choi)
 
  - Rework the handling of policy min and max frequency values in the
    cpufreq core to allow drivers to specify special initial values for
    the scaling_min_freq and scaling_max_freq sysfs attributes (Pierre
    Gondois)
 
  - Add cpufreq scaling support for Qualcomm Shikra SoC (Taniya Das,
    Imran Shaik).
 
  - Improve the warning message on HWP-disabled hybrid processors printed
    by the intel_pstate driver and sync policy->cur during CPU offline in
    it (Yohei Kojima, Fushuai Wang)
 
  - Drop cpufreq support for AMD Elan SC4* (Sean Young)
 
  - Minor fixes for cpufreq drivers (Krzysztof Kozlowski, Akashdeep Kaur,
    Hans Zhang, Guangshuo Li, Xueqin Luo)
 
  - Clean up dead dependencies on X86 in the cpufreq Kconfig (Julian
    Braha)
 
  - Allow the intel_idle driver to avoid exposing C-states that are
    redundant when PC6 is disabled (Artem Bityutskiy)
 
  - Fix memory leak and a potential race in the OPP core (Abdun Nihaal,
    Di Shen)
 
  - Mark Rust OPP methods as inline (Nicolás Antinori)
 
  - Fix misc device registration failure path in the PM QoS core (Yuho
    Choi)
 
  - Add sysctl interface for DPM watchdog timeouts (Tzung-Bi Shih)
 
  - Use complete() instead of complete_all() in device_pm_sleep_init() to
    avoid a false-positive warning from lockdep_assert_RT_in_threaded_ctx()
    when CONFIG_PROVE_RAW_LOCK_NESTING is enabled (Jiakai Xu)
 
  - Use a flexible array for CRC uncompressed buffers during hibernation
    image saving (Rosen Penev)
 
  - Make the LZ4 algorithm available for hibernation compression (l1rox3)
 
  - Move the preallocate_image() call during hibernation after the
    "prepare" phase of the "freeze" transition (Matthew Leach)
 
  - Fix a memory leak in rapl_add_package_cpuslocked() in the intel_rapl
    power capping driver and use sysfs_emit() in cpumask_show() in that
    driver (Sumeet Pawnikar, Yury Norov)
 
  - Fix ValueError when parsing incomplete device properties in the
    pm-graph utility (Gongwei Li)
 -----BEGIN PGP SIGNATURE-----
 
 iQFGBAABCAAwFiEEcM8Aw/RY0dgsiRUR7l+9nS/U47UFAmor9R8SHHJqd0Byand5
 c29ja2kubmV0AAoJEO5fvZ0v1OO1ODoIAInJsQeeWGXfUq4hAFnoA/gtS2oBw7Kw
 QVjoGG/DUbM/+ZtlbUee27pqvaYRY+q/Tv9RWKkl5vckASPFIAgCjImbm0g3P7Rz
 9OgoBwppqv0Yn5whFgc7nt9jOa7FQKV+jHiJgzRqwMxDFLkk0LldYVzsYpB6m+Lx
 Kca0LBeSv8o16EZX7RChC+6W7E5UhGxekSg9AzMPJTCe0gKciwARYiBhbSU5nAlI
 WdL5j+ycR3QTApbHA2tueaPKa1qnomLwJscmsE6UxlbikfcCBFZ9EvIsBnwl1WM4
 EcPA57IAYcr29N9Cdh/cs6MFkpWdzDBOs/ECZsgdI6fUWniQrPINThI=
 =oafL
 -----END PGP SIGNATURE-----

Merge tag 'pm-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "Over a half of the changes here are cpufreq updates that include core
  modifications, fixes of the old-style governors, new hardware support
  in drivers, assorded driver fixes and cleanups, and the removal of one
  driver (AMD Elan SC4*).

  Apart from that, the intel_idle driver will now be able to avoid
  exposing redundant C-states if PC6 is disabled and there are new
  sysctl knobs for device suspend/resume watchdog timeouts, hibernation
  gets built-in LZ4 support for image compression and there is the usual
  collection of assorted fixes and cleanups.

  Specifics:

   - Fix a race between cpufreq suspend and CPU hotplug during system
     shutdown (Tianxiang Chen)

   - Avoid redundant target() calls for unchanged limits and fix a typo
     in a comment in the cpufreq core (Viresh Kumar)

   - Fix concurrency issues related to sysfs attributes access that
     affect cpufreq governors using the common governor code (Zhongqiu
     Han)

   - Simplify frequency limit handling in the conservative cpufreq
     governor (Lifeng Zheng)

   - Fix descriptions of the conservative governor freq_step tunable and
     the ondemand governor sampling_down_factor tunable in the cpufreq
     documentation (Pengjie Zhang)

   - Fix use-after-free and double free during _OSC evaluation in the
     PCC cpufreq driver (Yuho Choi)

   - Rework the handling of policy min and max frequency values in the
     cpufreq core to allow drivers to specify special initial values for
     the scaling_min_freq and scaling_max_freq sysfs attributes (Pierre
     Gondois)

   - Add cpufreq scaling support for Qualcomm Shikra SoC (Taniya Das,
     Imran Shaik).

   - Improve the warning message on HWP-disabled hybrid processors
     printed by the intel_pstate driver and sync policy->cur during CPU
     offline in it (Yohei Kojima, Fushuai Wang)

   - Drop cpufreq support for AMD Elan SC4* (Sean Young)

   - Minor fixes for cpufreq drivers (Krzysztof Kozlowski, Akashdeep
     Kaur, Hans Zhang, Guangshuo Li, Xueqin Luo)

   - Clean up dead dependencies on X86 in the cpufreq Kconfig (Julian
     Braha)

   - Allow the intel_idle driver to avoid exposing C-states that are
     redundant when PC6 is disabled (Artem Bityutskiy)

   - Fix memory leak and a potential race in the OPP core (Abdun Nihaal,
     Di Shen)

   - Mark Rust OPP methods as inline (Nicolás Antinori)

   - Fix misc device registration failure path in the PM QoS core (Yuho
     Choi)

   - Add sysctl interface for DPM watchdog timeouts (Tzung-Bi Shih)

   - Use complete() instead of complete_all() in device_pm_sleep_init()
     to avoid a false-positive warning from lockdep_assert_RT_in_threaded_ctx()
     when CONFIG_PROVE_RAW_LOCK_NESTING is enabled (Jiakai Xu)

   - Use a flexible array for CRC uncompressed buffers during
     hibernation image saving (Rosen Penev)

   - Make the LZ4 algorithm available for hibernation compression
     (l1rox3)

   - Move the preallocate_image() call during hibernation after the
     "prepare" phase of the "freeze" transition (Matthew Leach)

   - Fix a memory leak in rapl_add_package_cpuslocked() in the
     intel_rapl power capping driver and use sysfs_emit() in
     cpumask_show() in that driver (Sumeet Pawnikar, Yury Norov)

   - Fix ValueError when parsing incomplete device properties in the
     pm-graph utility (Gongwei Li)"

* tag 'pm-7.2-rc1' of gitolite.kernel.org:pub/scm/linux/kernel/git/rafael/linux-pm: (40 commits)
  PM: dpm_watchdog: Add sysctl interface for DPM watchdog timeouts
  PM: QoS: Fix misc device registration unwind
  cpufreq: Use policy->min/max init as QoS request
  cpufreq: Remove driver default policy->min/max init
  cpufreq: Set default policy->min/max values for all drivers
  cpufreq: Extract cpufreq_policy_init_qos() function
  cpufreq: Documentation: fix conservative governor freq_step description
  cpufreq: ti: Add EPROBE_DEFER for K3 SoCs
  cpufreq: qcom: Add cpufreq scaling support for Qualcomm Shikra SoC
  dt-bindings: cpufreq: Document Qualcomm Shikra SoC EPSS
  powercap: intel_rapl: Use sysfs_emit() in cpumask_show()
  cpufreq: governor: Fix stale prev_cpu_nice spike when enabling ignore_nice_load
  cpufreq: governor: Fix data races on per-CPU idle/nice baselines
  PM: hibernate: Use flexible array for CRC uncompressed buffers
  powercap: intel_rapl: Fix memory leak in rapl_add_package_cpuslocked()
  PM: hibernate: make LZ4 available for hibernation compression
  PM: sleep: Use complete() in device_pm_sleep_init()
  opp: rust: mark OPP methods as inline
  cpufreq: intel_pstate: Improve warning message on HWP-disabled hybrid CPUs
  cpufreq: elanfreq: Drop support for AMD Elan SC4*
  ...
2026-06-15 11:37:18 +05:30
arch xen: branch for v7.2-rc1 2026-06-15 05:06:02 +05:30
block block-7.1-20260529 2026-05-29 10:41:07 -07:00
certs Clang build fixes for 7.1 2026-04-24 09:29:51 -07:00
crypto crypto/krb5, rxrpc: Fix lack of pre-decrypt/pre-verify length checks 2026-05-20 16:36:45 -07:00
Documentation Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
drivers Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
fs configfs work 2026-06-15 04:28:20 +05:30
include Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
init Rust changes for v7.2 2026-06-15 09:25:48 +05:30
io_uring io_uring-7.1-20260611 2026-06-12 10:49:59 -07:00
ipc kernel-7.2-rc1.misc 2026-06-15 03:05:50 +05:30
kernel Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
lib vfs-7.2-rc1.misc 2026-06-15 03:59:45 +05:30
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 vfs-7.2-rc1.misc 2026-06-15 03:59:45 +05:30
net vfs-7.2-rc1.xattr 2026-06-15 03:54:54 +05:30
rust Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
samples rust: dma: update to keyworded index projection syntax 2026-06-05 10:16:46 +02:00
scripts Rust changes for v7.2 2026-06-15 09:25:48 +05:30
security Kbuild / Kconfig changes for 7.2 2026-06-15 05:01:15 +05:30
sound ASoC: Fixes for v7.1 2026-06-11 21:29:47 +02:00
tools Power management updates for 7.2-rc1 2026-06-15 11:37:18 +05:30
usr kbuild: uapi: also test UAPI headers against C++ compilers 2026-03-25 13:24:42 +01:00
virt vfs-7.2-rc1.misc 2026-06-15 03:59:45 +05:30
.clang-format Devicetree updates for v7.0: 2026-02-11 18:27:08 -08:00
.clippy.toml rust: bump Clippy's MSRV and clean incompatible_msrv allows 2026-04-07 09:51:39 +02:00
.cocciconfig
.editorconfig editorconfig: add rst extension 2026-01-26 19:07:09 -08:00
.get_maintainer.ignore .get_maintainer.ignore: add Askar 2026-04-15 02:15:02 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Rust changes for v7.2 2026-06-15 09:25:48 +05:30
.mailmap MAINTAINERS: update Baoquan He's email address 2026-06-03 16:25:50 -07:00
.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
CREDITS Delete some obsolete networking code 2026-04-24 09:41:58 -07:00
Kbuild checksyscalls: move instance functionality into generic code 2026-04-05 09:21:32 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Rust changes for v7.2 2026-06-15 09:25:48 +05:30
Makefile Rust changes for v7.2 2026-06-15 09:25:48 +05:30
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