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Linus Torvalds bf76f23aa1 Scheduler updates for v6.17:
Core scheduler changes:
 
  - Better tracking of maximum lag of tasks in presence of different
    slices duration, for better handling of lag in the fair
    scheduler. (Vincent Guittot)
 
  - Clean up and standardize #if/#else/#endif markers throughout
    the entire scheduler code base (Ingo Molnar)
 
  - Make SMP unconditional: build the SMP scheduler's
    data structures and logic on UP kernel too, even though
    they are not used, to simplify the scheduler and remove
    around 200 #ifdef/[#else]/#endif blocks from the
    scheduler. (Ingo Molnar)
 
  - Reorganize cgroup bandwidth control interface handling
    for better interfacing with sched_ext (Tejun Heo)
 
 Balancing:
 
  - Bump sd->max_newidle_lb_cost when newidle balance fails (Chris Mason)
  - Remove sched_domain_topology_level::flags to simplify the code (Prateek Nayak)
  - Simplify and clean up build_sched_topology() (Li Chen)
  - Optimize build_sched_topology() on large machines (Li Chen)
 
 Real-time scheduling:
 
  - Add initial version of proxy execution: a mechanism for mutex-owning
    tasks to inherit the scheduling context of higher priority waiters.
    Currently limited to a single runqueue and conditional on CONFIG_EXPERT,
    and other limitations. (John Stultz, Peter Zijlstra, Valentin Schneider)
 
  - Deadline scheduler (Juri Lelli):
 
    - Fix dl_servers initialization order (Juri Lelli)
    - Fix DL scheduler's root domain reinitialization logic (Juri Lelli)
    - Fix accounting bugs after global limits change (Juri Lelli)
    - Fix scalability regression by implementing less agressive dl_server handling
      (Peter Zijlstra)
 
 PSI:
 
  - Improve scalability by optimizing psi_group_change() cpu_clock() usage
    (Peter Zijlstra)
 
 Rust changes:
 
  - Make Task, CondVar and PollCondVar methods inline to avoid unnecessary
    function calls (Kunwu Chan, Panagiotis Foliadis)
 
  - Add might_sleep() support for Rust code: Rust's "#[track_caller]"
    mechanism is used so that Rust's might_sleep() doesn't need to be
    defined as a macro (Fujita Tomonori)
 
  - Introduce file_from_location() (Boqun Feng)
 
 Debugging & instrumentation:
 
  - Make clangd usable with scheduler source code files again (Peter Zijlstra)
 
  - tools: Add root_domains_dump.py which dumps root domains info (Juri Lelli)
 
  - tools: Add dl_bw_dump.py for printing bandwidth accounting info (Juri Lelli)
 
 Misc cleanups & fixes:
 
  - Remove play_idle() (Feng Lee)
 
  - Fix check_preemption_disabled() (Sebastian Andrzej Siewior)
 
  - Do not call __put_task_struct() on RT if pi_blocked_on is set
    (Luis Claudio R. Goncalves)
 
  - Correct the comment in place_entity() (wang wei)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core scheduler changes:

   - Better tracking of maximum lag of tasks in presence of different
     slices duration, for better handling of lag in the fair scheduler
     (Vincent Guittot)

   - Clean up and standardize #if/#else/#endif markers throughout the
     entire scheduler code base (Ingo Molnar)

   - Make SMP unconditional: build the SMP scheduler's data structures
     and logic on UP kernel too, even though they are not used, to
     simplify the scheduler and remove around 200 #ifdef/[#else]/#endif
     blocks from the scheduler (Ingo Molnar)

   - Reorganize cgroup bandwidth control interface handling for better
     interfacing with sched_ext (Tejun Heo)

  Balancing:

   - Bump sd->max_newidle_lb_cost when newidle balance fails (Chris
     Mason)

   - Remove sched_domain_topology_level::flags to simplify the code
     (Prateek Nayak)

   - Simplify and clean up build_sched_topology() (Li Chen)

   - Optimize build_sched_topology() on large machines (Li Chen)

  Real-time scheduling:

   - Add initial version of proxy execution: a mechanism for
     mutex-owning tasks to inherit the scheduling context of higher
     priority waiters.

     Currently limited to a single runqueue and conditional on
     CONFIG_EXPERT, and other limitations (John Stultz, Peter Zijlstra,
     Valentin Schneider)

   - Deadline scheduler (Juri Lelli):
      - Fix dl_servers initialization order (Juri Lelli)
      - Fix DL scheduler's root domain reinitialization logic (Juri
        Lelli)
      - Fix accounting bugs after global limits change (Juri Lelli)
      - Fix scalability regression by implementing less agressive
        dl_server handling (Peter Zijlstra)

  PSI:

   - Improve scalability by optimizing psi_group_change() cpu_clock()
     usage (Peter Zijlstra)

  Rust changes:

   - Make Task, CondVar and PollCondVar methods inline to avoid
     unnecessary function calls (Kunwu Chan, Panagiotis Foliadis)

   - Add might_sleep() support for Rust code: Rust's "#[track_caller]"
     mechanism is used so that Rust's might_sleep() doesn't need to be
     defined as a macro (Fujita Tomonori)

   - Introduce file_from_location() (Boqun Feng)

  Debugging & instrumentation:

   - Make clangd usable with scheduler source code files again (Peter
     Zijlstra)

   - tools: Add root_domains_dump.py which dumps root domains info (Juri
     Lelli)

   - tools: Add dl_bw_dump.py for printing bandwidth accounting info
     (Juri Lelli)

  Misc cleanups & fixes:

   - Remove play_idle() (Feng Lee)

   - Fix check_preemption_disabled() (Sebastian Andrzej Siewior)

   - Do not call __put_task_struct() on RT if pi_blocked_on is set (Luis
     Claudio R. Goncalves)

   - Correct the comment in place_entity() (wang wei)"

* tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
  sched/idle: Remove play_idle()
  sched: Do not call __put_task_struct() on rt if pi_blocked_on is set
  sched: Start blocked_on chain processing in find_proxy_task()
  sched: Fix proxy/current (push,pull)ability
  sched: Add an initial sketch of the find_proxy_task() function
  sched: Fix runtime accounting w/ split exec & sched contexts
  sched: Move update_curr_task logic into update_curr_se
  locking/mutex: Add p->blocked_on wrappers for correctness checks
  locking/mutex: Rework task_struct::blocked_on
  sched: Add CONFIG_SCHED_PROXY_EXEC & boot argument to enable/disable
  sched/topology: Remove sched_domain_topology_level::flags
  x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled
  x86/smpboot: moves x86_topology to static initialize and truncate
  x86/smpboot: remove redundant CONFIG_SCHED_SMT
  smpboot: introduce SDTL_INIT() helper to tidy sched topology setup
  tools/sched: Add dl_bw_dump.py for printing bandwidth accounting info
  tools/sched: Add root_domains_dump.py which dumps root domains info
  sched/deadline: Fix accounting after global limits change
  sched/deadline: Reset extra_bw to max_bw when clearing root domains
  sched/deadline: Initialize dl_servers after SMP
  ...
2025-07-29 17:42:52 -07:00
Documentation Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
arch Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
block Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto Crypto library updates for 6.17 2025-07-28 17:58:52 -07:00
drivers - Map the SNP calling area pages too so that OVMF EFI fw can issue SVSM 2025-07-29 17:18:46 -07:00
fs Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
include Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
init Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
io_uring for-6.17/io_uring-20250728 2025-07-28 16:30:12 -07:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
lib Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
mm Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
net Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
rust Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
samples Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
scripts Driver core changes for 6.17-rc1 2025-07-29 12:15:39 -07:00
security Landlock update for v6.17-rc1 2025-07-28 19:21:32 -07:00
sound A treewide cleanup of struct cycle_counter const annotations: 2025-07-29 14:02:53 -07:00
tools Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt KVM: Allow CPU to reschedule while setting per-page memory attributes 2025-06-24 12:20:17 -07:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.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: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore Python compiled bytecode 2025-04-24 10:12:46 -06:00
.mailmap 11 hotfixes. 9 are cc:stable and the remainder address post-6.15 issues 2025-07-24 19:13:30 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING
CREDITS mm: update MAINTAINERS entry for HMM 2025-07-19 19:26:16 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Scheduler updates for v6.17: 2025-07-29 17:42:52 -07:00
Makefile hardening updates for v6.17-rc1 2025-07-28 17:16:12 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

README

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 reStructuredText 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.