kernel.git/Documentation/scheduler, branch linux-6.15.y

Merge tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-03-25T04:28:12Z

Pull scheduler updates from Ingo Molnar: "Core & fair scheduler changes: - Cancel the slice protection of the idle entity (Zihan Zhou) - Reduce the default slice to avoid tasks getting an extra tick (Zihan Zhou) - Force propagating min_slice of cfs_rq when {en,de}queue tasks (Tianchen Ding) - Refactor can_migrate_task() to elimate looping (I Hsin Cheng) - Add unlikey branch hints to several system calls (Colin Ian King) - Optimize current_clr_polling() on certain architectures (Yujun Dong) Deadline scheduler: (Juri Lelli) - Remove redundant dl_clear_root_domain call - Move dl_rebuild_rd_accounting to cpuset.h Uclamp: - Use the uclamp_is_used() helper instead of open-coding it (Xuewen Yan) - Optimize sched_uclamp_used static key enabling (Xuewen Yan) Scheduler topology support: (Juri Lelli) - Ignore special tasks when rebuilding domains - Add wrappers for sched_domains_mutex - Generalize unique visiting of root domains - Rebuild root domain accounting after every update - Remove partition_and_rebuild_sched_domains - Stop exposing partition_sched_domains_locked RSEQ: (Michael Jeanson) - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y - Fix segfault on registration when rseq_cs is non-zero - selftests: Add rseq syscall errors test - selftests: Ensure the rseq ABI TLS is actually 1024 bytes Membarriers: - Fix redundant load of membarrier_state (Nysal Jan K.A.) Scheduler debugging: - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior) - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar) Fixes and cleanups: - Always save/restore x86 TSC sched_clock() on suspend/resume (Guilherme G. Piccoli) - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian Andrzej Siewior)" * tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling() sched/debug: Remove CONFIG_SCHED_DEBUG sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional sched/debug: Make 'const_debug' tunables unconditional __read_mostly sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE() rseq/selftests: Fix namespace collision with rseq UAPI header include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h sched/topology: Stop exposing partition_sched_domains_locked cgroup/cpuset: Remove partition_and_rebuild_sched_domains sched/topology: Remove redundant dl_clear_root_domain call sched/deadline: Rebuild root domain accounting after every update sched/deadline: Generalize unique visiting of root domains sched/topology: Wrappers for sched_domains_mutex sched/deadline: Ignore special tasks when rebuilding domains tracing: Use preempt_model_str() xtensa: Rely on generic printing of preemption model x86: Rely on generic printing of preemption model s390: Rely on generic printing of preemption model ...

Merge tag 'docs-6.15' of git://git.lwn.net/linux

2025-03-25T01:42:27Z

Pull documentation updates from Jonathan Corbet: "It has been a reasonably busy cycle for docs... - Significant changes throughout the tree to bring Python code up to current standards and raise the minimum Python required to 3.9 Much of this is preparatory to replacing the ancient Perl scripts/kernel-doc horror with a slightly less horrifying Python implementation, expected for 6.16 - Update the minimum Sphinx required to 3.4.3, allowing us to remove a bunch of older compatibility code - Rework and improve the generation of the ABI documentation (All of the above done by Mauro) - Lots of translation updates. Alex Shi and Yanteng Si are taking on responsibility for the Chinese translations going forward; that work will still get to you via docs-next - Try to standardize the format for indicating a developer's affiliation in commit tags - Clarify the TAB's role in CoC enforcement actions - Try to spell out the rules for when a commit tag can name another developer without their explicit permission Plus lots of other typo fixes and updates" * tag 'docs-6.15' of git://git.lwn.net/linux: (98 commits) docs/zh_CN: fix spelling mistake docs/Chinese: change the disclaimer words docs/zh_CN: Add snp-tdx-threat-model index Chinese translation docs: driver-api: firmware: clarify userspace requirements docs: clarify rules wrt tagging other people docs: Remove outdated highuid.rst documentation Documentation: dma-buf: heaps: Add heap name definitions docs/.../submit-checklist: Use Documentation/admin-guide/abi.rst for cross-ref of README docs: Correct installation instruction Documentation: kcsan: fix "Plain Accesses and Data Races" URL in kcsan.rst Documentation/CoC: Spell out the TAB role in enforcement decisions Documentation: ocxl.rst: Update consortium site scripts: get_feat.pl: substitute s390x with s390 scripts/kernel-doc: drop dead code for Wcontents_before_sections scripts/kernel-doc: don't add not needed new lines docs: driver-api/infiniband.rst: fix Kerneldoc markup drivers: firewire: firewire-cdev.h: fix identation on a kernel-doc markup drivers: media: intel-ipu3.h: fix identation on a kernel-doc markup include/asm-generic/io.h: fix kerneldoc markup Docs/arch/arm64: Fix spelling in amu.rst ...

Merge tag 'sched_ext-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2025-03-25T00:23:48Z

Pull sched_ext updates from Tejun Heo: - Add mechanism to count and report internal events. This significantly improves visibility on subtle corner conditions. - The default idle CPU selection logic is revamped and improved in multiple ways including being made topology aware. - sched_ext was disabling ttwu_queue for simplicity, which can be costly when hardware topology is more complex. Implement SCX_OPS_ALLOWED_QUEUED_WAKEUP so that BPF schedulers can selectively enable ttwu_queue. - tools/sched_ext updates to improve compatibility among others. - Other misc updates and fixes. - sched_ext/for-6.14-fixes were pulled a few times to receive prerequisite fixes and resolve conflicts. * tag 'sched_ext-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (42 commits) sched_ext: idle: Refactor scx_select_cpu_dfl() sched_ext: idle: Honor idle flags in the built-in idle selection policy sched_ext: Skip per-CPU tasks in scx_bpf_reenqueue_local() sched_ext: Add trace point to track sched_ext core events sched_ext: Change the event type from u64 to s64 sched_ext: Documentation: add task lifecycle summary tools/sched_ext: Provide a compatible helper for scx_bpf_events() selftests/sched_ext: Add NUMA-aware scheduler test tools/sched_ext: Provide consistent access to scx flags sched_ext: idle: Fix scx_bpf_pick_any_cpu_node() behavior sched_ext: idle: Introduce scx_bpf_nr_node_ids() sched_ext: idle: Introduce node-aware idle cpu kfunc helpers sched_ext: idle: Per-node idle cpumasks sched_ext: idle: Introduce SCX_OPS_BUILTIN_IDLE_PER_NODE sched_ext: idle: Make idle static keys private sched/topology: Introduce for_each_node_numadist() iterator mm/numa: Introduce nearest_node_nodemask() nodemask: numa: reorganize inclusion path nodemask: add nodes_copy() tools/sched_ext: Sync with scx repo ...

sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation

2025-03-19T21:20:54Z

Since it's enabled unconditionally now, remove all references to it. (Left out languages I cannot read.) Signed-off-by: Ingo Molnar Tested-by: Shrikanth Hegde Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Mel Gorman Cc: Valentin Schneider Cc: Linus Torvalds Link: https://lore.kernel.org/r/20250317104257.3496611-5-mingo@kernel.org

sched/rt: Update limit of sched_rt sysctl in documentation

2025-03-06T09:21:31Z

By default fair_server dl_server allocates 5% of the bandwidth to the root domain. Due to this writing any value less than 5% fails due to -EBUSY: $ cat /proc/sys/kernel/sched_rt_period_us 1000000 $ echo 49999 > /proc/sys/kernel/sched_rt_runtime_us -bash: echo: write error: Device or resource busy $ echo 50000 > /proc/sys/kernel/sched_rt_runtime_us $ Since the sched_rt_runtime_us allows -1 as the minimum, put this restriction in the documentation. One should check average of runtime/period in /sys/kernel/debug/sched/fair_server/cpuX/* for exact value. Signed-off-by: Shrikanth Hegde Signed-off-by: Ingo Molnar Reviewed-by: Juri Lelli Link: https://lore.kernel.org/r/20250306052954.452005-3-sshegde@linux.ibm.com

sched_ext: Documentation: add task lifecycle summary

2025-02-27T16:28:23Z

Understanding the lifecycle of a task in sched_ext can be not trivial, therefore add a section to the main documentation that summarizes the entire workflow of a task using pseudo-code. Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo

docs: scheduler: fix spelling in sched-bwc documentation

2025-02-21T20:27:05Z

Fix spelling of "interference" in the CFS bandwidth control documentation. The word was misspelled as "interferenece". Signed-off-by: Suchit Karunakaran Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250219112254.28691-1-suchitkarunakaran@gmail.com

Merge tag 'sched_ext-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2025-01-24T02:49:43Z

Pull sched_ext updates from Tejun Heo: - scx_bpf_now() added so that BPF scheduler can access the cached timestamp in struct rq to avoid reading TSC multiple times within a locked scheduling operation. - Minor updates to the built-in idle CPU selection logic. - tool/sched_ext updates and other misc changes. * tag 'sched_ext-for-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: fix kernel-doc warnings sched_ext: Use time helpers in BPF schedulers sched_ext: Replace bpf_ktime_get_ns() to scx_bpf_now() sched_ext: Add time helpers for BPF schedulers sched_ext: Add scx_bpf_now() for BPF scheduler sched_ext: Implement scx_bpf_now() sched_ext: Relocate scx_enabled() related code sched_ext: Add option -l in selftest runner to list all available tests sched_ext: Include remaining task time slice in error state dump sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL_ON sched_ext: idle: small CPU iteration refactoring sched_ext: idle: introduce check_builtin_idle_enabled() helper sched_ext: idle: clarify comments sched_ext: idle: use assign_cpu() to update the idle cpumask sched_ext: Use str_enabled_disabled() helper in update_selcpu_topology() sched_ext: Use sizeof_field for key_len in dsq_hash_params tools/sched_ext: Receive updates from SCX repo sched_ext: Use the NUMA scheduling domain for NUMA optimizations

Merge tag 'docs-6.14' of git://git.lwn.net/linux

2025-01-22T02:00:00Z

Pull Documentation updates from Jonathan Corbet: - Quite a bit of Chinese and Spanish translation work - Clarifying that Git commit IDs >12chars are OK - A new nvme-multipath document - A reorganization of the admin-guide top-level page to make it readable - Clarification of the role of Acked-by and maintainer discretion on their acceptance - Some reorganization of debugging-oriented docs ... and typo fixes, documentation updates, etc as usual * tag 'docs-6.14' of git://git.lwn.net/linux: (50 commits) Documentation: Fix x86_64 UEFI outdated references to elilo Documentation/sysctl: Add timer_migration to kernel.rst docs/mm: Physical memory: Remove zone_t docs: submitting-patches: clarify that signers may use their discretion on tags docs: submitting-patches: clarify difference between Acked-by and Reviewed-by docs: submitting-patches: clarify Acked-by and introduce "# Suffix" Documentation: bug-hunting.rst: remove odd contact information docs/zh_CN: Add sak index Chinese translation doc: module: DEFAULT_SYMBOL_NAMESPACE must be defined before #includes doc: module: Fix documented type of namespace Documentation/kernel-parameters: Fix a reference to vga-softcursor.rst docs/zh_CN: Add landlock index Chinese translation Documentation: Fix typo localmodonfig -> localmodconfig overlayfs.rst: Fix and improve grammar docs/zh_CN: Add siphash index Chinese translation docs/zh_CN: Add security IMA-templates Chinese translation docs/zh_CN: Add security digsig Chinese translation Align git commit ID abbreviation guidelines and checks docs: process: submitting-patches: split canonical patch format section docs/zh_CN: Add security lsm Chinese translation ...

sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL_ON

2025-01-06T18:56:00Z

With commit 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches"), scx_bpf_dsq_insert() can use SCX_DSQ_LOCAL_ON for direct dispatch from ops.enqueue() to target the local DSQ of any CPU. Update the documentation accordingly. Fixes: 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches") Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo