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Linus Torvalds e32cde8d2b sched_ext: A second set of fixes for v6.12-rc1
- When sched_ext is in bypass mode (e.g. while disabling the BPF scheduler),
   it was using one DSQ to implement global FIFO scheduling as all it has to
   do is guaranteeing reasonable forward progress. On multi-socket machines,
   this can lead to live-lock conditions under certain workloads. Fixed by
   splitting the queue used for FIFO scheduling per NUMA node. This required
   several preparation patches.
 
 - Hotplug tests on powerpc could reliably trigger deadlock while enabling a
   BPF scheduler. This was caused by cpu_hotplug_lock nesting inside
   scx_fork_rwsem and then CPU hotplug path trying to fork a new thread while
   holding cpu_hotplug_lock. Fixed by restructuring locking in enable and
   disable paths so that the two locks are not coupled. This required several
   preparation patches which also fixed a couple other issues in the enable
   path.
 
 - A build fix for !CONFIG_SMP.
 
 - Userspace tooling sync and updates.
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Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - When sched_ext is in bypass mode (e.g. while disabling the BPF
   scheduler), it was using one DSQ to implement global FIFO scheduling
   as all it has to do is guaranteeing reasonable forward progress.

   On multi-socket machines, this can lead to live-lock conditions under
   certain workloads. Fixed by splitting the queue used for FIFO
   scheduling per NUMA node. This required several preparation patches.

 - Hotplug tests on powerpc could reliably trigger deadlock while
   enabling a BPF scheduler.

   This was caused by cpu_hotplug_lock nesting inside scx_fork_rwsem and
   then CPU hotplug path trying to fork a new thread while holding
   cpu_hotplug_lock.

   Fixed by restructuring locking in enable and disable paths so that
   the two locks are not coupled. This required several preparation
   patches which also fixed a couple other issues in the enable path.

 - A build fix for !CONFIG_SMP

 - Userspace tooling sync and updates

* tag 'sched_ext-for-6.12-rc1-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Remove redundant p->nr_cpus_allowed checker
  sched_ext: Decouple locks in scx_ops_enable()
  sched_ext: Decouple locks in scx_ops_disable_workfn()
  sched_ext: Add scx_cgroup_enabled to gate cgroup operations and fix scx_tg_online()
  sched_ext: Enable scx_ops_init_task() separately
  sched_ext: Fix SCX_TASK_INIT -> SCX_TASK_READY transitions in scx_ops_enable()
  sched_ext: Initialize in bypass mode
  sched_ext: Remove SCX_OPS_PREPPING
  sched_ext: Relocate check_hotplug_seq() call in scx_ops_enable()
  sched_ext: Use shorter slice while bypassing
  sched_ext: Split the global DSQ per NUMA node
  sched_ext: Relocate find_user_dsq()
  sched_ext: Allow only user DSQs for scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new()
  scx_flatcg: Use a user DSQ for fallback instead of SCX_DSQ_GLOBAL
  tools/sched_ext: Receive misc updates from SCX repo
  sched_ext: Add __COMPAT helpers for features added during v6.12 devel cycle
  sched_ext: Build fix for !CONFIG_SMP
2024-09-30 12:58:17 -07:00
arch x86: kvm: fix build error 2024-09-29 14:47:33 -07:00
block for-6.12/block-20240925 2024-09-25 14:56:40 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto KEYS: prevent NULL pointer dereference in find_asymmetric_key() 2024-09-20 19:49:49 +03:00
Documentation vfs-6.12-rc2.fixes 2024-09-30 10:59:44 -07:00
drivers mhu-v3, omap2+ : fix kconfig dependencies 2024-09-29 09:53:04 -07:00
fs vfs-6.12-rc2.fixes 2024-09-30 10:59:44 -07:00
include vfs-6.12-rc2.fixes 2024-09-30 10:59:44 -07:00
init Rust changes for v6.12 2024-09-25 10:25:40 -07:00
io_uring for-6.12/io_uring-20240922 2024-09-24 11:11:38 -07:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel sched_ext: A second set of fixes for v6.12-rc1 2024-09-30 12:58:17 -07:00
lib bitmap-for-6.12 2024-09-27 12:10:45 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm 19 hotfixes. 13 are cc:stable. 2024-09-27 10:27:22 -07:00
net Three CephFS fixes from Xiubo and Luis and a bunch of assorted 2024-09-28 08:40:36 -07:00
rust Rust changes for v6.12 2024-09-25 10:25:40 -07:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts Reduce Coccinelle choices in string_choices.cocci 2024-09-28 21:33:11 +02:00
security One bugfix patch, one preparation patch, and one conversion patch. 2024-09-27 12:03:48 -07:00
sound [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
tools sched_ext: A second set of fixes for v6.12-rc1 2024-09-30 12:58:17 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt x86: 2024-09-28 09:20:14 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap Summary 2024-09-24 11:08:40 -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 MAINTAINERS: Mark powerpc spufs as orphaned 2024-08-19 21:27:56 +10:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Modules changes for v6.12-rc1 2024-09-28 09:06:15 -07:00
Makefile Linux 6.12-rc1 2024-09-29 15:06:19 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.