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* Merge tag 'asm-generic-6.7' of ↵Linus Torvalds2023-11-021-3/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture
| * Documentation: Drop or replace remaining mentions of IA64Ard Biesheuvel2023-09-111-3/+1
| | | | | | | | | | | | Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
* | sched/topology: Remove the EM_MAX_COMPLEXITY limitPierre Gondois2023-10-091-26/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Energy Aware Scheduler (EAS) estimates the energy consumption of placing a task on different CPUs. The goal is to minimize this energy consumption. Estimating the energy of different task placements is increasingly complex with the size of the platform. To avoid having a slow wake-up path, EAS is only enabled if this complexity is low enough. The current complexity limit was set in: b68a4c0dba3b1 ("sched/topology: Disable EAS on inappropriate platforms") ... based on the first implementation of EAS, which was re-computing the power of the whole platform for each task placement scenario, see: 390031e4c309 ("sched/fair: Introduce an energy estimation helper function") ... but the complexity of EAS was reduced in: eb92692b2544d ("sched/fair: Speed-up energy-aware wake-ups") ... and find_energy_efficient_cpu() (feec) algorithm was updated in: 3e8c6c9aac42 ("sched/fair: Remove task_util from effective utilization in feec()") find_energy_efficient_cpu() (feec) is now doing: feec() \_ for_each_pd(pd) [0] // get max_spare_cap_cpu and compute_prev_delta \_ for_each_cpu(pd) [1] \_ eenv_pd_busy_time(pd) [2] \_ for_each_cpu(pd) // compute_energy(pd) without the task \_ eenv_pd_max_util(pd, -1) [3.0] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, -1) \_ for_each_ps(pd) // compute_energy(pd) with the task on prev_cpu \_ eenv_pd_max_util(pd, prev_cpu) [3.1] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, prev_cpu) \_ for_each_ps(pd) // compute_energy(pd) with the task on max_spare_cap_cpu \_ eenv_pd_max_util(pd, max_spare_cap_cpu) [3.2] \_ for_each_cpu(pd) \_ em_cpu_energy(pd, max_spare_cap_cpu) \_ for_each_ps(pd) [3.1] happens only once since prev_cpu is unique. With the same definitions for nr_pd, nr_cpus and nr_ps, the complexity is of: nr_pd * (2 * [nr_cpus in pd] + 2 * ([nr_cpus in pd] + [nr_ps in pd])) + ([nr_cpus in pd] + [nr_ps in pd]) [0] * ( [1] + [2] + [3.0] + [3.2] ) + [3.1] = nr_pd * (4 * [nr_cpus in pd] + 2 * [nr_ps in pd]) + [nr_cpus in prev pd] + nr_ps The complexity limit was set to 2048 in: b68a4c0dba3b1 ("sched/topology: Disable EAS on inappropriate platforms") ... to make "EAS usable up to 16 CPUs with per-CPU DVFS and less than 8 performance states each". For the same platform, the complexity would actually be of: 16 * (4 + 2 * 7) + 1 + 7 = 296 Since the EAS complexity was greatly reduced since the limit was introduced, bigger platforms can handle EAS. For instance, a platform with 112 CPUs with 7 performance states each would not reach it: 112 * (4 + 2 * 7) + 1 + 7 = 2024 To reflect this improvement in the underlying EAS code, remove the EAS complexity check. Note that a limit on the number of CPUs still holds against EM_MAX_NUM_CPUS to avoid overflows during the energy estimation. [ mingo: Updates to the changelog. ] Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20231009060037.170765-2-sshegde@linux.vnet.ibm.com
* | sched/topology: Consolidate and clean up access to a CPU's max compute capacityVincent Guittot2023-10-091-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the rq::cpu_capacity_orig field and use arch_scale_cpu_capacity() instead. The scheduler uses 3 methods to get access to a CPU's max compute capacity: - arch_scale_cpu_capacity(cpu) which is the default way to get a CPU's capacity. - cpu_capacity_orig field which is periodically updated with arch_scale_cpu_capacity(). - capacity_orig_of(cpu) which encapsulates rq->cpu_capacity_orig. There is no real need to save the value returned by arch_scale_cpu_capacity() in struct rq. arch_scale_cpu_capacity() returns: - either a per_cpu variable. - or a const value for systems which have only one capacity. Remove rq::cpu_capacity_orig and use arch_scale_cpu_capacity() everywhere. No functional changes. Some performance tests on Arm64: - small SMP device (hikey): no noticeable changes - HMP device (RB5): hackbench shows minor improvement (1-2%) - large smp (thx2): hackbench and tbench shows minor improvement (1%) Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20231009103621.374412-2-vincent.guittot@linaro.org
* | sched/rt/docs: Use 'real-time' instead of 'realtime'Cyril Hrubis2023-10-021-17/+17
| | | | | | | | | | | | | | | | Standardize on a single variant. Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-4-chrubis@suse.cz
* | sched/rt/docs: Clarify & fix sched_rt_* sysctl docsCyril Hrubis2023-10-021-6/+8
|/ | | | | | | | | | | | | - Describe explicitly that sched_rt_runtime_us is allocated from sched_rt_period_us and hence always less or equal to that value. - The limit for sched_rt_runtime_us is not INT_MAX-1, but rather it's limited by the value of sched_rt_period_us. If sched_rt_period_us is INT_MAX then sched_rt_runtime_us can be set to INT_MAX as well. Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-3-chrubis@suse.cz
* Merge tag 'docs-6.6' of git://git.lwn.net/linuxLinus Torvalds2023-08-313-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "Documentation work keeps chugging along; this includes: - Work from Carlos Bilbao to integrate rustdoc output into the generated HTML documentation. This took some work to figure out how to do it without slowing the docs build and without creating people who don't have Rust installed, but Carlos got there - Move the loongarch and mips architecture documentation under Documentation/arch/ - Some more maintainer documentation from Jakub ... plus the usual assortment of updates, translations, and fixes" * tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits) Docu: genericirq.rst: fix irq-example input: docs: pxrc: remove reference to phoenix-sim Documentation: serial-console: Fix literal block marker docs/mm: remove references to hmm_mirror ops and clean typos docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add() Documentation: Fix typos Documentation/ABI: Fix typos scripts: kernel-doc: fix macro handling in enums scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN] Documentation: riscv: Update boot image header since EFI stub is supported Documentation: riscv: Add early boot document Documentation: arm: Add bootargs to the table of added DT parameters docs: kernel-parameters: Refer to the correct bitmap function doc: update params of memhp_default_state= docs: Add book to process/kernel-docs.rst docs: sparse: fix invalid link addresses docs: vfs: clean up after the iterate() removal docs: Add a section on surveys to the researcher guidelines docs: move mips under arch docs: move loongarch under arch ...
| * Documentation: Fix typosBjorn Helgaas2023-08-182-3/+3
| | | | | | | | | | | | | | | | Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * docs: scheduler: completion: Fix minor error in pseudo-codeRick Wertenbroek2023-07-141-1/+1
| | | | | | | | | | | | | | | | Add missing address-of (&) operator in pseudo-code. Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230706114057.1120335-1-rick.wertenbroek@gmail.com
* | sched/eevdf/doc: Modify the documented knob to base_slice_ns as wellShrikanth Hegde2023-08-241-1/+1
|/ | | | | | | | | | | | | | | After committing the scheduler to EEVDF, we renamed the 'min_granularity_ns' sysctl to 'base_slice_ns': e4ec3318a17f ("sched/debug: Rename sysctl_sched_min_granularity to sysctl_sched_base_slice") ... but we forgot to rename it in the documentation. Do that now. Fixes: e4ec3318a17f ("sched/debug: Rename sysctl_sched_min_granularity to sysctl_sched_base_slice") Signed-off-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20230824080342.543396-1-sshegde@linux.vnet.ibm.com
* sched/deadline: Update GRUB description in the documentationVineeth Pillai2023-06-161-1/+4
| | | | | | | | | | Update the details of GRUB to reflect the updated logic. Signed-off-by: Vineeth Pillai (Google) <vineeth@bitbyteword.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@kernel.org> Acked-by: Juri Lelli <juri.lelli@redhat.com> Link: https://lore.kernel.org/r/20230530135526.2385378-2-vineeth@bitbyteword.org
* Merge tag 'sh-for-v6.4-tag1' of ↵Linus Torvalds2023-04-281-2/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux Pull sh updates from John Paul Adrian Glaubitz: "This is a bit larger than my previous one and mainly consists of clean-up work in the arch/sh directory by Geert Uytterhoeven and Randy Dunlap. Additionally, this fixes a bug in the Storage Queue code that was discovered while I was reviewing a patch to switch the code to the bitmap API by Christophe Jaillet. So this contains both a fix for the original bug in the Storage Queue code that can be backported later as well as the Christophe's patch to swich the code to the bitmap API. Summary: - Use generic GCC library routines - sq: Use the bitmap API when applicable - sq: Fix incorrect element size for allocating bitmap buffer - pci: Remove unused variable in SH-7786 PCI Express code - mcount.S: fix build error when PRINTK is not enabled - remove sh5/sh64 last fragments - math-emu: fix macro redefined warning - init: use OF_EARLY_FLATTREE for early init - nmi_debug: fix return value of __setup handler - SH2007: drop the bad URL info" * tag 'sh-for-v6.4-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux: sh: Replace <uapi/asm/types.h> by <asm-generic/int-ll64.h> sh: Use generic GCC library routines sh: sq: Use the bitmap API when applicable sh: sq: Fix incorrect element size for allocating bitmap buffer sh: pci: Remove unused variable in SH-7786 PCI Express code sh: mcount.S: fix build error when PRINTK is not enabled sh: remove sh5/sh64 last fragments sh: math-emu: fix macro redefined warning sh: init: use OF_EARLY_FLATTREE for early init sh: nmi_debug: fix return value of __setup handler sh: SH2007: drop the bad URL info
| * sh: remove sh5/sh64 last fragmentsRandy Dunlap2023-03-231-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A previous patch removed most of the sh5 (sh64) support from the kernel tree. Now remove the last stragglers. Fixes: 37744feebc08 ("sh: remove sh5 support") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: linux-sh@vger.kernel.org Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Link: https://lore.kernel.org/r/20230306040037.20350-6-rdunlap@infradead.org Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
* | sched/doc: supplement CPU capacity with RISC-VSong Shuai2023-03-071-1/+1
|/ | | | | | | | | | | | | | | | | This commit 7d2078310cbf ("dt-bindings: arm: move cpu-capacity to a shared loation") updates some references about capacity-dmips-mhz property in this document. The list of architectures using capacity-dmips-mhz omits RISC-V, so supplements it here. Signed-off-by: Song Shuai <suagrfillet@gmail.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> # English Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Reviewed-by: Alex Shi <alexs@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230227105941.2749193-1-suagrfillet@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Merge tag 'riscv-for-linus-6.3-mw1' of ↵Linus Torvalds2023-02-251-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: "There's a bunch of fixes/cleanups throughout the tree as usual, but we also have a handful of new features: - Various improvements to the extension detection and alternative patching infrastructure - Zbb-optimized string routines - Support for cpu-capacity in the RISC-V DT bindings - Zicbom no longer depends on toolchain support - Some performance and code size improvements to ftrace - Support for ARCH_WANT_LD_ORPHAN_WARN - Oops now contain the faulting instruction" * tag 'riscv-for-linus-6.3-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (67 commits) RISC-V: add a spin_shadow_stack declaration riscv: mm: hugetlb: Enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP riscv: Add header include guards to insn.h riscv: alternative: proceed one more instruction for auipc/jalr pair riscv: Avoid enabling interrupts in die() riscv, mm: Perform BPF exhandler fixup on page fault RISC-V: take text_mutex during alternative patching riscv: hwcap: Don't alphabetize ISA extension IDs RISC-V: fix ordering of Zbb extension riscv: jump_label: Fixup unaligned arch_static_branch function RISC-V: Only provide the single-letter extensions in HWCAP riscv: mm: fix regression due to update_mmu_cache change scripts/decodecode: Add support for RISC-V riscv: Add instruction dump to RISC-V splats riscv: select ARCH_WANT_LD_ORPHAN_WARN for !XIP_KERNEL riscv: vmlinux.lds.S: explicitly catch .init.bss sections from EFI stub riscv: vmlinux.lds.S: explicitly catch .riscv.attributes sections riscv: vmlinux.lds.S: explicitly catch .rela.dyn symbols riscv: lds: define RUNTIME_DISCARD_EXIT RISC-V: move some stray __RISCV_INSN_FUNCS definitions from kprobes ...
| * dt-bindings: arm: move cpu-capacity to a shared loationConor Dooley2023-02-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RISC-V uses the same generic topology code as arm64 & while there currently exists no binding for cpu-capacity on RISC-V, the code paths can be hit if the property is present. Move the documentation of cpu-capacity to a shared location, ahead of defining a binding for capacity-dmips-mhz on RISC-V. Update some references to this document in the process. Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com> Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Yanteng Si <siyanteng@loongson.cn> Link: https://lore.kernel.org/r/20230104180513.1379453-2-conor@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | Merge tag 'docs-6.3' of git://git.lwn.net/linuxLinus Torvalds2023-02-221-3/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "It has been a moderately calm cycle for documentation; the significant changes include: - Some significant additions to the memory-management documentation - Some improvements to navigation in the HTML-rendered docs - More Spanish and Chinese translations ... and the usual set of typo fixes and such" * tag 'docs-6.3' of git://git.lwn.net/linux: (68 commits) Documentation/watchdog/hpwdt: Fix Format Documentation/watchdog/hpwdt: Fix Reference Documentation: core-api: padata: correct spelling docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSION docs: Use HTML comments for the kernel-toc SPDX line docs: Add more information to the HTML sidebar Documentation: KVM: Update AMD memory encryption link printk: Document that CONFIG_BOOT_PRINTK_DELAY required for boot_delay= Documentation: userspace-api: correct spelling Documentation: sparc: correct spelling Documentation: driver-api: correct spelling Documentation: admin-guide: correct spelling docs: add workload-tracing document to admin-guide docs/admin-guide/mm: remove useless markup docs/mm: remove useless markup docs/mm: Physical Memory: remove useless markup docs/sp_SP: Add process magic-number translation docs: ftrace: always use canonical ftrace path Doc/damon: fix the data path error dma-buf: Add "dma-buf" to title of documentation ...
| * | Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed ↵SeongJae Park2023-01-241-3/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | documents Some documents that listed on subsystem-apis have 'Linux' or 'The Linux' title prefixes. It's duplicated information, and makes finding the document of interest with human eyes not easy. Remove the prefixes from the titles. Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Iwona Winiarska <iwona.winiarska@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230122184834.181977-1-sj@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* / sched/documentation: Document the util clamp featureQais Yousef2023-01-052-0/+742
|/ | | | | | | | | | | | | Add a document explaining the util clamp feature: what it is and how to use it. The new document hopefully covers everything one needs to know about uclamp. Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Link: https://lore.kernel.org/r/20221216235716.201923-1-qyousef@layalina.io Cc: Jonathan Corbet <corbet@lwn.net>
* docs: scheduler: Update new path for the sysctl knobsLukasz Luba2022-09-271-1/+1
| | | | | | | | | | | Add missing update for the documentation bit of some scheduler knob. The knobs have been moved to /debug/sched/ location (with adjusted names). Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Reviewed-by: Alex Shi <alexs@kernel.org> Tested-by: Yanteng Si <siyanteng@loongson.cn> Link: https://lore.kernel.org/r/20220816121907.841-1-lukasz.luba@arm.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* docs/scheduler: fix unit errorJui-Tse Huang2022-04-161-2/+2
| | | | | | | | | | | | | | | | | | | The unit mentioned in the documentation of scheduler statistics is outdated which may mislead the readers. The unit of statistics that is reported by /proc/schedstat is modified to nanosecond, and the unit of statistics that is reported by /proc/PID/schedstat is provided as well to make the context consistent. The rq_cpu_time and the rq_sched_info.run_delay of a run queue, and the sched_info.run_delay of a task are all updated based on the clock of the run queue, while the se.sum_exec_runtime of a task is updated based on the clock_task of the run queue of the task. Both the clock and clock_task are relied on the return value of the function sched_clock() which is in the unit of nanosecond. Signed-off-by: Jui-Tse Huang <juitse.huang@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* docs/scheduler: Change unit of cpu_time and rq_time to nanosecondsChunguang Xu2022-04-161-2/+2
| | | | | | | | In the current implementation, cpu_time and rq_time should be in nanoseconds, so this document needs to be modified. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Merge tag 'sched-core-2022-03-22' of ↵Linus Torvalds2022-03-222-0/+55
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Cleanups for SCHED_DEADLINE - Tracing updates/fixes - CPU Accounting fixes - First wave of changes to optimize the overhead of the scheduler build, from the fast-headers tree - including placeholder *_api.h headers for later header split-ups. - Preempt-dynamic using static_branch() for ARM64 - Isolation housekeeping mask rework; preperatory for further changes - NUMA-balancing: deal with CPU-less nodes - NUMA-balancing: tune systems that have multiple LLC cache domains per node (eg. AMD) - Updates to RSEQ UAPI in preparation for glibc usage - Lots of RSEQ/selftests, for same - Add Suren as PSI co-maintainer * tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits) sched/headers: ARM needs asm/paravirt_api_clock.h too sched/numa: Fix boot crash on arm64 systems headers/prep: Fix header to build standalone: <linux/psi.h> sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y cgroup: Fix suspicious rcu_dereference_check() usage warning sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity() sched/deadline,rt: Remove unused functions for !CONFIG_SMP sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy() sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file sched/deadline: Remove unused def_dl_bandwidth sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE sched/tracing: Don't re-read p->state when emitting sched_switch event sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race sched/cpuacct: Remove redundant RCU read lock sched/cpuacct: Optimize away RCU read lock sched/cpuacct: Fix charge percpu cpuusage sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies ...
| * sched/numa-balancing: Move some document to make it consistent with the codeHuang Ying2022-02-112-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commit 8a99b6833c88 ("sched: Move SCHED_DEBUG sysctl to debugfs"), some NUMA balancing sysctls enclosed with SCHED_DEBUG has been moved to debugfs. This patch move the document for these sysctls from Documentation/admin-guide/sysctl/kernel.rst to Documentation/scheduler/sched-debug.rst to make the document consistent with the code. Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lkml.kernel.org/r/20220210052514.3038279-1-ying.huang@intel.com
* | docs: scheduler: Convert schedutil.txt to ReSTTang Yizhou2022-03-162-13/+18
| | | | | | | | | | | | | | | | | | | | | | All other scheduler documents have been converted to *.rst. Let's do the same for schedutil.txt. Also fixed some typos. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Link: https://lore.kernel.org/r/20220312070751.16844-1-tangyizhou@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | docs: scheduler: Fix outdated parameter of rebalance_domainsTang Yizhou2022-02-021-4/+4
|/ | | | | | | | | According to the function prototype of rebalance_domains(), its first parameter is *rq* and the document need to be updated. Signed-off-by: Tang Yizhou <tangyizhou@huawei.com> Link: https://lore.kernel.org/r/20211221031818.23186-1-tangyizhou@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* docs/scheduler: fix typo and warning in sched-bwcYanteng Si2021-12-061-3/+2
| | | | | | | | | | | | | | | | | | a) since d73df887b6b8 ("sched/fair: Add document for burstable CFS bandwidth") [cpu.cfs_quota_us: the total available run-time within a period (in] shoud be removed, let's delete it. b) Add a period. c) fix a build warning: linux-next/Documentation/scheduler/sched-bwc.rst:243: WARNING: Inline emphasis start-string without end-string. Signed-off-by: Yanteng Si <siyanteng@loongson.cn> Reviewed-by: Alex Shi <alexs@kernel.org> Link: https://lore.kernel.org/r/163a4dde20b8c4b68d668977a668e281d18fcf92.1638517064.git.siyanteng@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* sched/fair: Add document for burstable CFS bandwidthHuaixin Chang2021-10-051-9/+75
| | | | | | | | | | | | | | Basic description of usage and effect for CFS Bandwidth Control Burst. Co-developed-by: Shanpei Chen <shanpeic@linux.alibaba.com> Signed-off-by: Shanpei Chen <shanpeic@linux.alibaba.com> Co-developed-by: Tianchen Ding <dtcccc@linux.alibaba.com> Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com> Signed-off-by: Huaixin Chang <changhuaixin@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210830032215.16302-3-changhuaixin@linux.alibaba.com
* Merge tag 'docs-5.14' of git://git.lwn.net/linuxLinus Torvalds2021-06-292-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "This was a reasonably active cycle for documentation; this includes: - Some kernel-doc cleanups. That script is still regex onslaught from hell, but it has gotten a little better. - Improvements to the checkpatch docs, which are also used by the tool itself. - A major update to the pathname lookup documentation. - Elimination of :doc: markup, since our automarkup magic can create references from filenames without all the extra noise. - The flurry of Chinese translation activity continues. Plus, of course, the usual collection of updates, typo fixes, and warning fixes" * tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits) docs: path-lookup: use bare function() rather than literals docs: path-lookup: update symlink description docs: path-lookup: update get_link() ->follow_link description docs: path-lookup: update WALK_GET, WALK_PUT desc docs: path-lookup: no get_link() docs: path-lookup: update i_op->put_link and cookie description docs: path-lookup: i_op->follow_link replaced with i_op->get_link docs: path-lookup: Add macro name to symlink limit description docs: path-lookup: remove filename_mountpoint docs: path-lookup: update do_last() part docs: path-lookup: update path_mountpoint() part docs: path-lookup: update path_to_nameidata() part docs: path-lookup: update follow_managed() part docs: Makefile: Use CONFIG_SHELL not SHELL docs: Take a little noise out of the build process docs: x86: avoid using ReST :doc:`foo` markup docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup ...
| * docs: sched-bwc.rst: fix a typo on a doc nameMauro Carvalho Chehab2021-05-201-1/+1
| | | | | | | | | | | | | | | | cgroupv2.rst -> cgroup-v2.rst Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/1dc0203bd7df375ef45832f0c88566e22c4138ff.1621413933.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * Documentation: scheduler: fixed 2 typos in sched-nice-design.rstChun-Hung Tseng2021-05-171-1/+1
| | | | | | | | | | | | | | | | This patch fixed 2 spelling errors in the documentation. Signed-off-by: Chun-Hung Tseng <henrybear327@gmail.com> Link: https://lore.kernel.org/r/20210516105955.120651-1-henrybear327@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | sched/doc: Update the CPU capacity asymmetry bitsBeata Michalska2021-06-242-3/+5
|/ | | | | | | | | | | | Update the documentation bits referring to capacity aware scheduling with regards to newly introduced SD_ASYM_CPUCAPACITY_FULL sched_domain flag. Signed-off-by: Beata Michalska <beata.michalska@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Link: https://lore.kernel.org/r/20210603140627.8409-4-beata.michalska@arm.com
* sched,doc: sched_debug_verbose cmdline should be sched_verboseBarry Song2021-05-061-1/+1
| | | | | | | | | | | The cmdline should include sched_verbose but not sched_debug_verbose as sched_debug_verbose is only the variant name in code. Fixes: 9406415f46 ("sched/debug: Rename the sched_debug parameter to sched_verbose") Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20210504105344.31344-1-song.bao.hua@hisilicon.com
* sched/debug: Rename the sched_debug parameter to sched_verbosePeter Zijlstra2021-04-171-5/+5
| | | | | | | | | CONFIG_SCHED_DEBUG is the build-time Kconfig knob, the boot param sched_debug and the /debug/sched/debug_enabled knobs control the sched_debug_enabled variable, but what they really do is make SCHED_DEBUG more verbose, so rename the lot. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
* Merge tag 'docs-5.12' of git://git.lwn.net/linuxLinus Torvalds2021-02-223-9/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
| * docs/scheduler/sched-bwc: note/link cgroup v2Kir Kolyshkin2021-01-211-0/+5
| | | | | | | | | | | | | | Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210120001824.385168-6-kolyshkin@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * docs/scheduler/sched-bwc: fix note renderingKir Kolyshkin2021-01-211-2/+3
| | | | | | | | | | | | | | Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210120001824.385168-4-kolyshkin@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * docs/scheduler/sched-design-CFS: formatting fixKir Kolyshkin2021-01-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | Fix the rendering of the paragraph. Before the fix, the first line is rendered in bold (I'm not quite sure why) and is also separated from the rest of the paragraph, which is rendered with an indent. Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210120001824.385168-3-kolyshkin@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * docs/scheduler/sched-bwc: formatting fixKir Kolyshkin2021-01-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | Since commit d6a3b247627a3 these three lines are merged into one by the RST processor, making it hard to read. Use bullet points to separate the entries, like it's done in other similar places. Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20210120001824.385168-2-kolyshkin@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
| * Documentation: Replace lkml.org links with loreJoe Perches2021-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the lkml.org links with lore to better use a single source that's more likely to stay available long-term. Done by bash script: cvt_lkml_to_lore () { tmpfile=$(mktemp ./.cvt_links.XXXXXXX) header=$(echo $1 | sed 's@/lkml/@/lkml/headers/@') wget -qO - $header > $tmpfile if [[ $? == 0 ]] ; then link=$(grep -i '^Message-Id:' $tmpfile | head -1 | \ sed -r -e 's/^\s*Message-Id:\s*<\s*//' -e 's/\s*>\s*$//' -e 's@^@https://lore.kernel.org/r/@') # echo "testlink: $link" if [ -n "$link" ] ; then wget -qO - $link > /dev/null if [[ $? == 0 ]] ; then echo $link fi fi fi rm -f $tmpfile } git grep -P -o "\bhttps?://(?:www.)?lkml.org/lkml[\/\w]+" $@ | while read line ; do echo $line file=$(echo $line | cut -f1 -d':') link=$(echo $line | cut -f2- -d':') newlink=$(cvt_lkml_to_lore $link) if [[ -n "$newlink" ]] ; then sed -i -e "s#\b$link\b#$newlink#" $file fi done Link: https://lore.kernel.org/patchwork/patch/1265849/#1462688 Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/77cdb7f32cfb087955bfc3600b86c40bed5d4104.camel@perches.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* | sched: Add schedutil overviewPeter Zijlstra2021-01-141-0/+169
|/ | | | | | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Morten Rasmussen <morten.rasmussen@arm.com> Link: https://lkml.kernel.org/r/20201218103258.GA3040@hirez.programming.kicks-ass.net
* Merge tag 'pm-5.11-rc1' of ↵Linus Torvalds2020-12-161-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "These update cpufreq (core and drivers), cpuidle (polling state implementation and the PSCI driver), the OPP (operating performance points) framework, devfreq (core and drivers), the power capping RAPL (Running Average Power Limit) driver, the Energy Model support, the generic power domains (genpd) framework, the ACPI device power management, the core system-wide suspend code and power management utilities. Specifics: - Use local_clock() instead of jiffies in the cpufreq statistics to improve accuracy (Viresh Kumar). - Fix up OPP usage in the cpufreq-dt and qcom-cpufreq-nvmem cpufreq drivers (Viresh Kumar). - Clean up the cpufreq core, the intel_pstate driver and the schedutil cpufreq governor (Rafael Wysocki). - Fix up error code paths in the sti-cpufreq and mediatek cpufreq drivers (Yangtao Li, Qinglang Miao). - Fix cpufreq_online() to return error codes instead of success (0) in all cases when it fails (Wang ShaoBo). - Add mt8167 support to the mediatek cpufreq driver and blacklist mt8516 in the cpufreq-dt-platdev driver (Fabien Parent). - Modify the tegra194 cpufreq driver to always return values from the frequency table as the current frequency and clean up that driver (Sumit Gupta, Jon Hunter). - Modify the arm_scmi cpufreq driver to allow it to discover the power scale present in the performance protocol and provide this information to the Energy Model (Lukasz Luba). - Add missing MODULE_DEVICE_TABLE to several cpufreq drivers (Pali Rohár). - Clean up the CPPC cpufreq driver (Ionela Voinescu). - Fix NVMEM_IMX_OCOTP dependency in the imx cpufreq driver (Arnd Bergmann). - Rework the poling interval selection for the polling state in cpuidle (Mel Gorman). - Enable suspend-to-idle for PSCI OSI mode in the PSCI cpuidle driver (Ulf Hansson). - Modify the OPP framework to support empty (node-less) OPP tables in DT for passing dependency information (Nicola Mazzucato). - Fix potential lockdep issue in the OPP core and clean up the OPP core (Viresh Kumar). - Modify dev_pm_opp_put_regulators() to accept a NULL argument and update its users accordingly (Viresh Kumar). - Add frequency changes tracepoint to devfreq (Matthias Kaehlcke). - Add support for governor feature flags to devfreq, make devfreq sysfs file permissions depend on the governor and clean up the devfreq core (Chanwoo Choi). - Clean up the tegra20 devfreq driver and deprecate it to allow another driver based on EMC_STAT to be used instead of it (Dmitry Osipenko). - Add interconnect support to the tegra30 devfreq driver, allow it to take the interconnect and OPP information from DT and clean it up (Dmitry Osipenko). - Add interconnect support to the exynos-bus devfreq driver along with interconnect properties documentation (Sylwester Nawrocki). - Add suport for AMD Fam17h and Fam19h processors to the RAPL power capping driver (Victor Ding, Kim Phillips). - Fix handling of overly long constraint names in the powercap framework (Lukasz Luba). - Fix the wakeup configuration handling for bridges in the ACPI device power management core (Rafael Wysocki). - Add support for using an abstract scale for power units in the Energy Model (EM) and document it (Lukasz Luba). - Add em_cpu_energy() micro-optimization to the EM (Pavankumar Kondeti). - Modify the generic power domains (genpd) framwework to support suspend-to-idle (Ulf Hansson). - Fix creation of debugfs nodes in genpd (Thierry Strudel). - Clean up genpd (Lina Iyer). - Clean up the core system-wide suspend code and make it print driver flags for devices with debug enabled (Alex Shi, Patrice Chotard, Chen Yu). - Modify the ACPI system reboot code to make it prepare for system power off to avoid confusing the platform firmware (Kai-Heng Feng). - Update the pm-graph (multiple changes, mostly usability-related) and cpupower (online and offline CPU information support) PM utilities (Todd Brandt, Brahadambal Srinivasan)" * tag 'pm-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (86 commits) cpufreq: Fix cpufreq_online() return value on errors cpufreq: Fix up several kerneldoc comments cpufreq: stats: Use local_clock() instead of jiffies cpufreq: schedutil: Simplify sugov_update_next_freq() cpufreq: intel_pstate: Simplify intel_cpufreq_update_pstate() PM: domains: create debugfs nodes when adding power domains opp: of: Allow empty opp-table with opp-shared dt-bindings: opp: Allow empty OPP tables media: venus: dev_pm_opp_put_*() accepts NULL argument drm/panfrost: dev_pm_opp_put_*() accepts NULL argument drm/lima: dev_pm_opp_put_*() accepts NULL argument PM / devfreq: exynos: dev_pm_opp_put_*() accepts NULL argument cpufreq: qcom-cpufreq-nvmem: dev_pm_opp_put_*() accepts NULL argument cpufreq: dt: dev_pm_opp_put_regulators() accepts NULL argument opp: Allow dev_pm_opp_put_*() APIs to accept NULL opp_table opp: Don't create an OPP table from dev_pm_opp_get_opp_table() cpufreq: dt: Don't (ab)use dev_pm_opp_get_opp_table() to create OPP table opp: Reduce the size of critical section in _opp_kref_release() PM / EM: Micro optimization in em_cpu_energy cpufreq: arm_scmi: Discover the power scale in performance protocol ...
| * PM: EM: Clarify abstract scale usage for power values in Energy ModelLukasz Luba2020-11-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Energy Model (EM) can store power values in milli-Watts or in abstract scale. This might cause issues in the subsystems which use the EM for estimating the device power, such as: - mixing of different scales in a subsystem which uses multiple (cooling) devices (e.g. thermal Intelligent Power Allocation (IPA)) - assuming that energy [milli-Joules] can be derived from the EM power values which might not be possible since the power scale doesn't have to be in milli-Watts To avoid misconfiguration add the requisite documentation to the EM and related subsystems: EAS and IPA. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Documentation: scheduler: fix information on arch SD flags, sched_domain and ↵Barry Song2020-11-191-15/+11
|/ | | | | | | | | | | | | | | | | | | | | | | | sched_debug This document seems to be out of date for many, many years. Even it has misspelled from the first day. ARCH_HASH_SCHED_TUNE should be ARCH_HAS_SCHED_TUNE ARCH_HASH_SCHED_DOMAIN should be ARCH_HAS_SCHED_DOMAIN Since v2.6.14, kernel completely deleted the relevant code and even arch_init_sched_domains() was deleted. Right now, kernel is asking architectures to call set_sched_topology() to override the default sched domains. On the other hand, to print the schedule debug information, users need to set sched_debug cmdline or enable it by sysfs entry. So this patch also adds the description for sched_debug. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20201113115018.1628-1-song.bao.hua@hisilicon.com
* docs: scheduler: fix the directory name on two filesMauro Carvalho Chehab2020-09-102-2/+2
| | | | | | | | | | The name of the directory where the schedule docs are stored are wrong on those files. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lore.kernel.org/r/a32c2bba17aa69dc18670b7de1a3a35bfa1e1f88.1599660067.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* sched/doc: Factorize bits between sched-energy.rst & sched-capacity.rstValentin Schneider2020-08-011-10/+2
| | | | | | | | | | Documentation/scheduler/sched-capacity.rst ought to be the canonical place to blabber about SD_ASYM_CPUCAPACITY, so remove its explanation from sched-energy.rst and point to sched-capacity.rst instead. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200731192016.7484-4-valentin.schneider@arm.com
* sched/doc: Document capacity aware schedulingValentin Schneider2020-08-012-0/+440
| | | | | | | | | | Add some documentation detailing the concepts, requirements and implementation of capacity aware scheduling across the different scheduler classes. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200731192016.7484-3-valentin.schneider@arm.com
* Documentation: scheduler: fix outdated information on sched groupsAdrian Freund2020-04-211-4/+6
| | | | | | | | | | | The documentation claims that two sched groups must not overlap. This is no longer true, as overlapping sched groups are used on NUMA systems. This change has been introduced by commit e3589f6c81e47 and was documented by an in-code comment in commit 35a566e6e8a18. Signed-off-by: Adrian Freund <adrian@freund.io> Link: https://lore.kernel.org/r/20200407130525.76663-1-adrian@freund.io Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* Documentation/scheduler: fix links in sched-statsAndre Azevedo2019-10-291-2/+2
| | | | | | | | | | The rain.com domain recently moved to pdxhosts.com, making the scheduler documentation point to broken links. Fix the links in the scheduler documentation. CC: Rick Lindsley <ricklind@linux.vnet.ibm.com> Signed-off-by: Andre Azevedo <andre.azevedo@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* sched/fair: Fix low cpu usage with high throttling by removing expiration of ↵Dave Chiluk2019-08-081-14/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpu-local slices It has been observed, that highly-threaded, non-cpu-bound applications running under cpu.cfs_quota_us constraints can hit a high percentage of periods throttled while simultaneously not consuming the allocated amount of quota. This use case is typical of user-interactive non-cpu bound applications, such as those running in kubernetes or mesos when run on multiple cpu cores. This has been root caused to cpu-local run queue being allocated per cpu bandwidth slices, and then not fully using that slice within the period. At which point the slice and quota expires. This expiration of unused slice results in applications not being able to utilize the quota for which they are allocated. The non-expiration of per-cpu slices was recently fixed by 'commit 512ac999d275 ("sched/fair: Fix bandwidth timer clock drift condition")'. Prior to that it appears that this had been broken since at least 'commit 51f2176d74ac ("sched/fair: Fix unlocked reads of some cfs_b->quota/period")' which was introduced in v3.16-rc1 in 2014. That added the following conditional which resulted in slices never being expired. if (cfs_rq->runtime_expires != cfs_b->runtime_expires) { /* extend local deadline, drift is bounded above by 2 ticks */ cfs_rq->runtime_expires += TICK_NSEC; Because this was broken for nearly 5 years, and has recently been fixed and is now being noticed by many users running kubernetes (https://github.com/kubernetes/kubernetes/issues/67577) it is my opinion that the mechanisms around expiring runtime should be removed altogether. This allows quota already allocated to per-cpu run-queues to live longer than the period boundary. This allows threads on runqueues that do not use much CPU to continue to use their remaining slice over a longer period of time than cpu.cfs_period_us. However, this helps prevent the above condition of hitting throttling while also not fully utilizing your cpu quota. This theoretically allows a machine to use slightly more than its allotted quota in some periods. This overflow would be bounded by the remaining quota left on each per-cpu runqueueu. This is typically no more than min_cfs_rq_runtime=1ms per cpu. For CPU bound tasks this will change nothing, as they should theoretically fully utilize all of their quota in each period. For user-interactive tasks as described above this provides a much better user/application experience as their cpu utilization will more closely match the amount they requested when they hit throttling. This means that cpu limits no longer strictly apply per period for non-cpu bound applications, but that they are still accurate over longer timeframes. This greatly improves performance of high-thread-count, non-cpu bound applications with low cfs_quota_us allocation on high-core-count machines. In the case of an artificial testcase (10ms/100ms of quota on 80 CPU machine), this commit resulted in almost 30x performance improvement, while still maintaining correct cpu quota restrictions. That testcase is available at https://github.com/indeedeng/fibtest. Fixes: 512ac999d275 ("sched/fair: Fix bandwidth timer clock drift condition") Signed-off-by: Dave Chiluk <chiluk+linux@indeed.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Phil Auld <pauld@redhat.com> Reviewed-by: Ben Segall <bsegall@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: John Hammond <jhammond@indeed.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kyle Anderson <kwa@yelp.com> Cc: Gabriel Munos <gmunoz@netflix.com> Cc: Peter Oskolkov <posk@posk.io> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Brendan Gregg <bgregg@netflix.com> Link: https://lkml.kernel.org/r/1563900266-19734-2-git-send-email-chiluk+linux@indeed.com
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