torvalds-linux/Documentation
Linus Torvalds 62de6e1685 Scheduler enhancements for v6.14:
- Fair scheduler (SCHED_FAIR) enhancements:
 
    - Behavioral improvements:
      - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra)
 
    - Delayed-dequeue enhancements & fixes: (Vincent Guittot)
 
      - Rename h_nr_running into h_nr_queued
      - Add new cfs_rq.h_nr_runnable
      - Use the new cfs_rq.h_nr_runnable
      - Removed unsued cfs_rq.h_nr_delayed
      - Rename cfs_rq.idle_h_nr_running into h_nr_idle
      - Remove unused cfs_rq.idle_nr_running
      - Rename cfs_rq.nr_running into nr_queued
      - Do not try to migrate delayed dequeue task
      - Fix variable declaration position
      - Encapsulate set custom slice in a __setparam_fair() function
 
    - Fixes:
      - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding)
      - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal Chourasia)
 
    - Cleanups:
      - Clean up in migrate_degrades_locality() to improve
        readability (Peter Zijlstra)
      - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko)
      - Update comments after sched_tick() rename (Sebastian Andrzej Siewior)
      - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used()
        (Valentin Schneider)
 
  - Deadline scheduler (SCHED_DL) enhancements:
 
    - Restore dl_server bandwidth on non-destructive root domain
      changes (Juri Lelli)
 
    - Correctly account for allocated bandwidth during
      hotplug (Juri Lelli)
 
    - Check bandwidth overflow earlier for hotplug (Juri Lelli)
 
    - Clean up goto label in pick_earliest_pushable_dl_task()
      (John Stultz)
 
    - Consolidate timer cancellation (Wander Lairson Costa)
 
  - Load-balancer enhancements:
 
    - Improve performance by prioritizing migrating eligible
      tasks in sched_balance_rq() (Hao Jia)
 
    - Do not compute NUMA Balancing stats unnecessarily during
      load-balancing (K Prateek Nayak)
 
    - Do not compute overloaded status unnecessarily during
      load-balancing (K Prateek Nayak)
 
  - Generic scheduling code enhancements:
 
    - Use READ_ONCE() in task_on_rq_queued(), to consistently use
      the WRITE_ONCE() updated ->on_rq field (Harshit Agarwal)
 
  - Isolated CPUs support enhancements: (Waiman Long)
 
    - Make "isolcpus=nohz" equivalent to "nohz_full"
    - Consolidate housekeeping cpumasks that are always identical
    - Remove HK_TYPE_SCHED
    - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE
 
  - RSEQ enhancements:
 
    - Validate read-only fields under DEBUG_RSEQ config
      (Mathieu Desnoyers)
 
  - PSI enhancements:
 
    - Fix race when task wakes up before psi_sched_switch()
      adjusts flags (Chengming Zhou)
 
  - IRQ time accounting performance enhancements: (Yafang Shao)
 
    - Define sched_clock_irqtime as static key
    - Don't account irq time if sched_clock_irqtime is disabled
 
  - Virtual machine scheduling enhancements:
 
    - Don't try to catch up excess steal time (Suleiman Souhlal)
 
  - Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak)
 
    - Convert "sysctl_sched_itmt_enabled" to boolean
    - Use guard() for itmt_update_mutex
    - Move the "sched_itmt_enabled" sysctl to debugfs
    - Remove x86_smt_flags and use cpu_smt_flags directly
    - Use x86_sched_itmt_flags for PKG domain unconditionally
 
  - Debugging code & instrumentation enhancements:
 
    - Change need_resched warnings to pr_err() (David Rientjes)
    - Print domain name in /proc/schedstat (K Prateek Nayak)
    - Fix value reported by hot tasks pulled in /proc/schedstat (Peter Zijlstra)
    - Report the different kinds of imbalances in /proc/schedstat (Swapnil Sapkal)
    - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal)
    - Update Schedstat version to 17 (Swapnil Sapkal)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Fair scheduler (SCHED_FAIR) enhancements:

   - Behavioral improvements:
      - Untangle NEXT_BUDDY and pick_next_task() (Peter Zijlstra)

   - Delayed-dequeue enhancements & fixes: (Vincent Guittot)
      - Rename h_nr_running into h_nr_queued
      - Add new cfs_rq.h_nr_runnable
      - Use the new cfs_rq.h_nr_runnable
      - Removed unsued cfs_rq.h_nr_delayed
      - Rename cfs_rq.idle_h_nr_running into h_nr_idle
      - Remove unused cfs_rq.idle_nr_running
      - Rename cfs_rq.nr_running into nr_queued
      - Do not try to migrate delayed dequeue task
      - Fix variable declaration position
      - Encapsulate set custom slice in a __setparam_fair() function

   - Fixes:
      - Fix race between yield_to() and try_to_wake_up() (Tianchen Ding)
      - Fix CPU bandwidth limit bypass during CPU hotplug (Vishal
        Chourasia)

   - Cleanups:
      - Clean up in migrate_degrades_locality() to improve readability
        (Peter Zijlstra)
      - Mark m*_vruntime() with __maybe_unused (Andy Shevchenko)
      - Update comments after sched_tick() rename (Sebastian Andrzej
        Siewior)
      - Remove CONFIG_CFS_BANDWIDTH=n definition of cfs_bandwidth_used()
        (Valentin Schneider)

  Deadline scheduler (SCHED_DL) enhancements:

   - Restore dl_server bandwidth on non-destructive root domain changes
     (Juri Lelli)

   - Correctly account for allocated bandwidth during hotplug (Juri
     Lelli)

   - Check bandwidth overflow earlier for hotplug (Juri Lelli)

   - Clean up goto label in pick_earliest_pushable_dl_task() (John
     Stultz)

   - Consolidate timer cancellation (Wander Lairson Costa)

  Load-balancer enhancements:

   - Improve performance by prioritizing migrating eligible tasks in
     sched_balance_rq() (Hao Jia)

   - Do not compute NUMA Balancing stats unnecessarily during
     load-balancing (K Prateek Nayak)

   - Do not compute overloaded status unnecessarily during
     load-balancing (K Prateek Nayak)

  Generic scheduling code enhancements:

   - Use READ_ONCE() in task_on_rq_queued(), to consistently use the
     WRITE_ONCE() updated ->on_rq field (Harshit Agarwal)

  Isolated CPUs support enhancements: (Waiman Long)

   - Make "isolcpus=nohz" equivalent to "nohz_full"
   - Consolidate housekeeping cpumasks that are always identical
   - Remove HK_TYPE_SCHED
   - Unify HK_TYPE_{TIMER|TICK|MISC} to HK_TYPE_KERNEL_NOISE

  RSEQ enhancements:

   - Validate read-only fields under DEBUG_RSEQ config (Mathieu
     Desnoyers)

  PSI enhancements:

   - Fix race when task wakes up before psi_sched_switch() adjusts flags
     (Chengming Zhou)

  IRQ time accounting performance enhancements: (Yafang Shao)

   - Define sched_clock_irqtime as static key
   - Don't account irq time if sched_clock_irqtime is disabled

  Virtual machine scheduling enhancements:

   - Don't try to catch up excess steal time (Suleiman Souhlal)

  Heterogenous x86 CPU scheduling enhancements: (K Prateek Nayak)

   - Convert "sysctl_sched_itmt_enabled" to boolean
   - Use guard() for itmt_update_mutex
   - Move the "sched_itmt_enabled" sysctl to debugfs
   - Remove x86_smt_flags and use cpu_smt_flags directly
   - Use x86_sched_itmt_flags for PKG domain unconditionally

  Debugging code & instrumentation enhancements:

   - Change need_resched warnings to pr_err() (David Rientjes)
   - Print domain name in /proc/schedstat (K Prateek Nayak)
   - Fix value reported by hot tasks pulled in /proc/schedstat (Peter
     Zijlstra)
   - Report the different kinds of imbalances in /proc/schedstat
     (Swapnil Sapkal)
   - Move sched domain name out of CONFIG_SCHED_DEBUG (Swapnil Sapkal)
   - Update Schedstat version to 17 (Swapnil Sapkal)"

* tag 'sched-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rseq: Fix rseq unregistration regression
  psi: Fix race when task wakes up before psi_sched_switch() adjusts flags
  sched, psi: Don't account irq time if sched_clock_irqtime is disabled
  sched: Don't account irq time if sched_clock_irqtime is disabled
  sched: Define sched_clock_irqtime as static key
  sched/fair: Do not compute overloaded status unnecessarily during lb
  sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb
  x86/topology: Use x86_sched_itmt_flags for PKG domain unconditionally
  x86/topology: Remove x86_smt_flags and use cpu_smt_flags directly
  x86/itmt: Move the "sched_itmt_enabled" sysctl to debugfs
  x86/itmt: Use guard() for itmt_update_mutex
  x86/itmt: Convert "sysctl_sched_itmt_enabled" to boolean
  sched/core: Prioritize migrating eligible tasks in sched_balance_rq()
  sched/debug: Change need_resched warnings to pr_err
  sched/fair: Encapsulate set custom slice in a __setparam_fair() function
  sched: Fix race between yield_to() and try_to_wake_up()
  docs: Update Schedstat version to 17
  sched/stats: Print domain name in /proc/schedstat
  sched: Move sched domain name out of CONFIG_SCHED_DEBUG
  sched: Report the different kinds of imbalances in /proc/schedstat
  ...
2025-01-21 11:32:36 -08:00
..
ABI cxl: Deprecate driver 2024-12-13 09:15:28 +05:30
accel
accounting
admin-guide Scheduler enhancements for v6.14: 2025-01-21 11:32:36 -08:00
arch Miscellaneous x86 cleanups and typo fixes, and also the removal 2025-01-21 11:15:29 -08:00
block
bpf
cdrom
core-api module: Convert default symbol namespace to string literal 2024-12-03 08:22:25 -08:00
cpu-freq
crypto
dev-tools Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
devicetree Char/Misc/IIO driver fixes for 6.13-rc7 2025-01-12 14:34:00 -08:00
doc-guide Documentation: kernel-doc: enumerate identifier *type*s 2024-11-22 10:37:40 -07:00
driver-api Driver core changes for 6.13-rc1 2024-11-29 11:43:29 -08:00
fault-injection net: Implement fault injection forcing skb reallocation 2024-11-12 12:05:33 +01:00
fb
features
filesystems bcachefs updates for 6.14-rc1 2025-01-20 13:55:19 -08:00
firmware_class
firmware-guide
fpga
gpu
hid
hwmon hwmon: (tmp108) Add NXP p3t1085 support 2024-11-12 13:54:55 -08:00
i2c i2c-host updates for v6.13, part 1 2024-11-18 08:35:47 +01:00
iio
images
infiniband
input Input: fix the input_event struct documentation 2024-11-14 18:03:23 -08:00
isdn
kbuild Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
kernel-hacking docs/licensing: Clarify wording about "GPL" and "Proprietary" 2024-11-22 10:44:25 -07:00
leds
litmus-tests
livepatch
locking locking/Documentation: Fix grammar in percpu-rw-semaphore.rst 2024-11-13 10:59:01 +01:00
maintainer
mhi
misc-devices
mm docs/mm: add VMA locks documentation 2024-12-18 19:04:41 -08:00
netlabel
netlink netlink: specs: mptcp: fix missing doc 2024-12-27 11:16:21 -08:00
networking Documentation: networking: Add a caveat to nexthop_compat_mode sysctl 2024-12-10 18:26:24 -08:00
nvdimm
nvme Documentation: Document the NVMe PCI endpoint target driver 2025-01-10 19:30:49 -08:00
PCI Documentation: Document the NVMe PCI endpoint target driver 2025-01-10 19:30:49 -08:00
pcmcia
peci
power Documentation: PM: Clarify pm_runtime_resume_and_get() return value 2024-12-10 20:14:22 +01:00
process A few late-arriving fixes, plus two more significant changes that were 2024-11-26 13:44:27 -08:00
RCU doc: rcu: update printed dynticks counter bits 2024-11-12 21:40:24 +01:00
rust Rust changes for v6.13 2024-11-26 14:00:26 -08:00
scheduler docs: Update Schedstat version to 17 2024-12-20 15:31:18 +01:00
scsi
security cred: remove unused get_new_cred() 2024-12-02 11:25:14 +01:00
sound ALSA: doc: Add codecs/index.rst to top-level index 2025-01-09 11:15:56 +00:00
sphinx
sphinx-static
spi
staging
target
tee
timers
tools
trace ftrace: Document that multiple function_graph tracing may have different times 2025-01-14 10:45:24 -05:00
translations module: Convert default symbol namespace to string literal 2024-12-03 08:22:25 -08:00
usb
userspace-api drm for 6.13-rc1 2024-11-21 14:56:17 -08:00
virt KVM: s390: Reject KVM_SET_GSI_ROUTING on ucontrol VMs 2025-01-07 16:36:11 +01:00
w1
watchdog
wmi platform-drivers-x86 for v6.13-1 2024-11-20 14:07:55 -08:00
.gitignore
atomic_bitops.txt
atomic_t.txt
Changes
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conf.py
docutils.conf
index.rst
Kconfig
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memory-barriers.txt
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subsystem-apis.rst Documentation: Document the NVMe PCI endpoint target driver 2025-01-10 19:30:49 -08:00