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Linus Torvalds 91959a31a3 kho: make boot time huge page allocation work nicely with KHO
Today allocation of gigantic pages in HugeTLB cannot work reliably with KHO:
 
 * HugeTLB allocates gigantic pages using memblock and autoscaling of KHO
   scratch accounts for these allocations. When gigantic pages occupy half
   of the memory of more, KHO fails to allocate its scratch memory.
 * After kexec handover, memblock allocations exclusively use KHO scratch
   that is not supposed to contain preserved memory. This essentially blocks
   preservation of HugeTLB with gigantic pages.
 
 Extend early memory pools available for KHO kernel with areas that are
 guaranteed not to contain preserved memory.
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Merge tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux

Pull more liveupdate updates from Mike Rapoport:
 "Make boot time huge page allocation work nicely with kexec handover.

  Today allocation of gigantic pages in HugeTLB cannot work reliably
  with kexec handover (KHO):

   - HugeTLB allocates gigantic pages using memblock and autoscaling of
     KHO scratch accounts for these allocations. When gigantic pages
     occupy half of the memory of more, KHO fails to allocate its
     scratch memory.

   - After kexec handover, memblock allocations exclusively use KHO
     scratch that is not supposed to contain preserved memory. This
     essentially blocks preservation of HugeTLB with gigantic pages.

  Extend early memory pools available for KHO kernel with areas that are
  guaranteed not to contain preserved memory"

* tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (21 commits)
  kho: exclude hugetlb memory from scratch size calculation
  memblock: add memblock_reserved_hugetlb_size()
  memblock: make HugeTLB bootmem allocation work with KHO
  memblock: always include KHO headers
  kho: extend scratch
  mm/mm_init: don't rely on memblock to get KHO scratch migratetype
  kho: initialize preserved memory map radix tree earlier
  kho: initialize kho_scratch pointer earlier in boot
  kho: expose kho_scratch_overlap() to kexec_handover.h
  kho: add kho_radix_init_tree()
  kho: allow destroying KHO radix tree
  kho: allow early-boot usage of the KHO radix tree
  kho: add data argument to radix walk callback
  kho: add callback for table pages
  kho: add a struct for radix callbacks
  kho: move all memory retrieval logic to kho_mem_retrieve()
  kho: store incoming radix tree in kho_in
  kho: disallow wide keys in radix tree
  kho: make radix max key width more obvious
  kho: generalize radix tree APIs
  ...
2026-08-23 09:17:38 -07:00
arch kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
block for-7.3/block-20260819 2026-08-20 13:55:16 -07:00
certs treewide: fix indentation and whitespace in Kconfig files 2026-05-28 21:24:42 -07:00
crypto This update includes the following changes: 2026-08-19 17:25:42 -07:00
Documentation * Raw NAND changes 2026-08-23 09:11:21 -07:00
drivers * Raw NAND changes 2026-08-23 09:11:21 -07:00
fs This contains a set of 142 SMB server updates focused on SMB2 command 2026-08-23 08:41:36 -07:00
include kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
init mm.git review status for mm-hotfixes-stable..mm-stable 2026-08-20 18:17:08 -07:00
io_uring for-7.3/block-20260819 2026-08-20 13:55:16 -07:00
ipc mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
kernel kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
lib mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
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 kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
net RDMA v7.3 merge window pull 2026-08-21 11:48:54 -07:00
rust Modules changes for 7.3-rc1 2026-08-21 12:47:25 -07:00
samples Modules changes for 7.3-rc1 2026-08-21 12:47:25 -07:00
scripts mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -07:00
security Hi, 2026-08-23 08:29:33 -07:00
sound mm.git review status for mm-hotfixes-stable..mm-stable 2026-08-20 18:17:08 -07:00
tools kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
usr usr: Correct a spelling by changing a letter 2026-08-05 14:51:58 +02:00
virt mm: use linear_page_[index, delta]() consistently 2026-08-04 19:19:01 -07:00
.clang-format drm/bridge: rename drm_for_each_bridge_in_chain_scoped() to drm_for_each_bridge_in_chain() 2026-07-14 17:55:51 +02:00
.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 Nathan Chancellor 2026-08-03 21:10:12 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore SPDX patches for 7.2-rc1 2026-06-22 12:06:22 -07:00
.mailmap mm.git review status for master..mm-nonmm-stable 2026-08-23 08:07:11 -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 COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS CIFS Maintainer switch 2026-08-21 12:16:31 -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 kho: make boot time huge page allocation work nicely with KHO 2026-08-23 09:17:38 -07:00
Makefile livepatching changes for 7.3 2026-08-21 13:11:56 -07:00
README README: remove out of place emdashes 2026-07-15 10:51:29 -06:00

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