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2021-05-10bitmap_parse: Support 'all' semanticsYury Norov1-0/+5
RCU code supports an 'all' group as a special case when parsing rcu_nocbs parameter. This patch moves the 'all' support to the core bitmap_parse code, so that all bitmap users can enjoy this extension. Moving 'all' parsing to a bitmap_parse level also allows users to pass patterns together with 'all' in regular group:pattern format, for example, "rcu_nocbs=all:1/2" would offload all the even-numbered CPUs regardless of the number of CPUs on the system. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-04-28Merge tag 'core-rcu-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+7
Pull RCU updates from Ingo Molnar: - Support for "N" as alias for last bit in bitmap parsing library (eg using syntax like "nohz_full=2-N") - kvfree_rcu updates - mm_dump_obj() updates. (One of these is to mm, but was suggested by Andrew Morton.) - RCU callback offloading update - Polling RCU grace-period interfaces - Realtime-related RCU updates - Tasks-RCU updates - Torture-test updates - Torture-test scripting updates - Miscellaneous fixes * tag 'core-rcu-2021-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) rcutorture: Test start_poll_synchronize_rcu() and poll_state_synchronize_rcu() rcu: Provide polling interfaces for Tiny RCU grace periods torture: Fix kvm.sh --datestamp regex check torture: Consolidate qemu-cmd duration editing into kvm-transform.sh torture: Print proper vmlinux path for kvm-again.sh runs torture: Make TORTURE_TRUST_MAKE available in kvm-again.sh environment torture: Make kvm-transform.sh update jitter commands torture: Add --duration argument to kvm-again.sh torture: Add kvm-again.sh to rerun a previous torture-test torture: Create a "batches" file for build reuse torture: De-capitalize TORTURE_SUITE torture: Make upper-case-only no-dot no-slash scenario names official torture: Rename SRCU-t and SRCU-u to avoid lowercase characters torture: Remove no-mpstat error message torture: Record kvm-test-1-run.sh and kvm-test-1-run-qemu.sh PIDs torture: Record jitter start/stop commands torture: Extract kvm-test-1-run-qemu.sh from kvm-test-1-run.sh torture: Record TORTURE_KCONFIG_GDB_ARG in qemu-cmd torture: Abstract jitter.sh start/stop into scripts rcu: Provide polling interfaces for Tree RCU grace periods ...
2021-03-08Documentation/admin-guide: kernel-parameters: correct the architectures for numa_balancingBarry Song1-0/+1
X86 isn't the only architecture supporting NUMA_BALANCING. ARM64, PPC, S390 and RISCV also support it: arch$ git grep NUMA_BALANCING arm64/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING arm64/configs/defconfig:CONFIG_NUMA_BALANCING=y arm64/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/configs/powernv_defconfig:CONFIG_NUMA_BALANCING=y powerpc/configs/ppc64_defconfig:CONFIG_NUMA_BALANCING=y powerpc/configs/pseries_defconfig:CONFIG_NUMA_BALANCING=y powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/include/asm/book3s/64/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/book3s/64/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/include/asm/nohash/pgtable.h:#ifdef CONFIG_NUMA_BALANCING powerpc/include/asm/nohash/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ powerpc/platforms/Kconfig.cputype: select ARCH_SUPPORTS_NUMA_BALANCING riscv/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING riscv/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING s390/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING s390/configs/debug_defconfig:CONFIG_NUMA_BALANCING=y s390/configs/defconfig:CONFIG_NUMA_BALANCING=y s390/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING x86/Kconfig: select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 x86/include/asm/pgtable.h:#ifdef CONFIG_NUMA_BALANCING x86/include/asm/pgtable.h:#endif /* CONFIG_NUMA_BALANCING */ On the other hand, setup_numabalancing() is implemented in mm/mempolicy.c which doesn't depend on architectures. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20210302084159.33688-1-song.bao.hua@hisilicon.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-08lib: bitmap: support "N" as an alias for size of bitmapPaul Gortmaker1-0/+7
While this is done for all bitmaps, the original use case in mind was for CPU masks and cpulist_parse() as described below. It seems that a common configuration is to use the 1st couple cores for housekeeping tasks. This tends to leave the remaining ones to form a pool of similarly configured cores to take on the real workload of interest to the user. So on machine A - with 32 cores, it could be 0-3 for "system" and then 4-31 being used in boot args like nohz_full=, or rcu_nocbs= as part of setting up the worker pool of CPUs. But then newer machine B is added, and it has 48 cores, and so while the 0-3 part remains unchanged, the pool setup cpu list becomes 4-47. Multiple deployment becomes easier when we can just simply replace 31 and 47 with "N" and let the system substitute in the actual number at boot; a number that it knows better than we do. Cc: Yury Norov <yury.norov@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Yury Norov <yury.norov@gmail.com> # move it from CPU code Acked-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-28Documentation: kernel-parameters: add missing '<'Wolfram Sang1-1/+1
Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Link: https://lore.kernel.org/r/20210127104343.5647-1-wsa+renesas@sang-engineering.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-31Documentation: admin: early_param()s are also listed in kernel-parametersRandy Dunlap1-2/+2
Add info that "early_param()" kernel boot parameters are also listed in kernel-parameters.txt. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20201226174433.7885-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-11-30Documentation/admin-guide: mark memmap parameter is supported by a few architecturesBarry Song1-0/+1
early_param memmap is only implemented on X86, MIPS and XTENSA. To avoid wasting users’ time on trying this on platform like ARM, mark it clearly. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20201128195121.2556-1-song.bao.hua@hisilicon.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-10-04of: property: Add functional dependency link from DT bindingsSaravana Kannan1-0/+1
Add device links after the devices are created (but before they are probed) by looking at common DT bindings like clocks and interconnects. Automatically adding device links for functional dependencies at the framework level provides the following benefits: - Optimizes device probe order and avoids the useless work of attempting probes of devices that will not probe successfully (because their suppliers aren't present or haven't probed yet). For example, in a commonly available mobile SoC, registering just one consumer device's driver at an initcall level earlier than the supplier device's driver causes 11 failed probe attempts before the consumer device probes successfully. This was with a kernel with all the drivers statically compiled in. This problem gets a lot worse if all the drivers are loaded as modules without direct symbol dependencies. - Supplier devices like clock providers, interconnect providers, etc need to keep the resources they provide active and at a particular state(s) during boot up even if their current set of consumers don't request the resource to be active. This is because the rest of the consumers might not have probed yet and turning off the resource before all the consumers have probed could lead to a hang or undesired user experience. Some frameworks (Eg: regulator) handle this today by turning off "unused" resources at late_initcall_sync and hoping all the devices have probed by then. This is not a valid assumption for systems with loadable modules. Other frameworks (Eg: clock) just don't handle this due to the lack of a clear signal for when they can turn off resources. This leads to downstream hacks to handle cases like this that can easily be solved in the upstream kernel. By linking devices before they are probed, we give suppliers a clear count of the number of dependent consumers. Once all of the consumers are active, the suppliers can turn off the unused resources without making assumptions about the number of consumers. By default we just add device-links to track "driver presence" (probe succeeded) of the supplier device. If any other functionality provided by device-links are needed, it is left to the consumer/supplier devices to change the link when they probe. kbuild test robot reported clang error about missing const Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20190904211126.47518-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-15docs: m68k: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert the m68k kernel-options.txt file to ReST. The conversion is trivial, as the document is already on a format close enough to ReST. Just some small adjustments were needed in order to make it both good for being parsed while keeping it on a good txt shape. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-06-28docs: format kernel-parameters -- as codeStephen Kitt1-2/+2
The current ReStructuredText formatting results in "--", used to indicate the end of the kernel command-line parameters, appearing as an en-dash instead of two hyphens; this patch formats them as code, "``--``", as done elsewhere in the documentation. Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab1-3/+3
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-01Documentation: Add ARM64 to kernel-parameters.rstJosh Poimboeuf1-0/+1
Add ARM64 to the legend of architectures. It's already used in several places in kernel-parameters.txt. Suggested-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-16arch: remove blackfin portArnd Bergmann1-1/+0
The Analog Devices Blackfin port was added in 2007 and was rather active for a while, but all work on it has come to a standstill over time, as Analog have changed their product line-up. Aaron Wu confirmed that the architecture port is no longer relevant, and multiple people suggested removing blackfin independently because of some of its oddities like a non-working SMP port, and the amount of duplication between the chip variants, which cause extra work when doing cross-architecture changes. Link: https://docs.blackfin.uclinux.org/ Acked-by: Aaron Wu <Aaron.Wu@analog.com> Acked-by: Bryan Wu <cooloney@gmail.com> Cc: Steven Miao <realmz6@gmail.com> Cc: Mike Frysinger <vapier@chromium.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2017-12-18sched/isolation: Document boot parameters dependency on CONFIG_CPU_ISOLATION=yFrederic Weisbecker1-0/+1
The "isolcpus=" and "nohz_full=" boot parameters depend on CPU Isolation support. Let's document that. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <kernellwp@gmail.com> Cc: kernel test robot <xiaolong.ye@intel.com> Link: http://lkml.kernel.org/r/1513275507-29200-4-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25x86/intel_rdt: Add command line options for resource director technologyTony Luck1-0/+1
Command line options allow us to ignore features that we don't want. Also we can re-enable options that have been disabled on a platform (so long as the underlying h/w actually supports the option). [ tglx: Marked the option array __initdata and the helper function __init ] Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua" <fenghua.yu@intel.com> Cc: Ravi V" <ravi.v.shankar@intel.com> Cc: "Peter Zijlstra" <peterz@infradead.org> Cc: "Stephane Eranian" <eranian@google.com> Cc: "Andi Kleen" <ak@linux.intel.com> Cc: "David Carrillo-Cisneros" <davidcc@google.com> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Link: http://lkml.kernel.org/r/0c37b0d4dbc30977a3c1cee08b66420f83662694.1503512900.git.tony.luck@intel.com
2017-05-02Merge tag 'docs-4.12' of git://git.lwn.net/linuxLinus Torvalds1-1/+3
Pull documentation update from Jonathan Corbet: "A reasonably busy cycle for documentation this time around. There is a new guide for user-space API documents, rather sparsely populated at the moment, but it's a start. Markus improved the infrastructure for converting diagrams. Mauro has converted much of the USB documentation over to RST. Plus the usual set of fixes, improvements, and tweaks. There's a bit more than the usual amount of reaching out of Documentation/ to fix comments elsewhere in the tree; I have acks for those where I could get them" * tag 'docs-4.12' of git://git.lwn.net/linux: (74 commits) docs: Fix a couple typos docs: Fix a spelling error in vfio-mediated-device.txt docs: Fix a spelling error in ioctl-number.txt MAINTAINERS: update file entry for HSI subsystem Documentation: allow installing man pages to a user defined directory Doc/PM: Sync with intel_powerclamp code behavior zr364xx.rst: usb/devices is now at /sys/kernel/debug/ usb.rst: move documentation from proc_usb_info.txt to USB ReST book convert philips.txt to ReST and add to media docs docs-rst: usb: update old usbfs-related documentation arm: Documentation: update a path name docs: process/4.Coding.rst: Fix a couple of document refs docs-rst: fix usb cross-references usb: gadget.h: be consistent at kernel doc macros usb: composite.h: fix two warnings when building docs usb: get rid of some ReST doc build errors usb.rst: get rid of some Sphinx errors usb/URB.txt: convert to ReST and update it usb/persist.txt: convert to ReST and add to driver-api book usb/hotplug.txt: convert to ReST and add to driver-api book ...
2017-05-01docs: remove all references to AVR32 architectureHans-Christian Noren Egtvedt1-1/+0
The AVR32 architecture support has been removed from the Linux kernel, hence remove all references to it from Documentation. Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> Signed-off-by: Håvard Skinnemoen <hskinnemoen@gmail.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
2017-04-20docs: process/4.Coding.rst: Fix a couple of document refsAndrew Clayton1-0/+2
In Documentation/process/4.Coding.rst there were a couple of paragraphs that spilled over the 80 character line length. This was likely caused when the document was converted to reStructuredText. Re-flow the paragraphs and make the document references proper reStructuredText :ref: links. This also adds the appropriate reStructuredText file heading to kernel-parameters.rst as referenced by the kernel-parameters link in this patch. Signed-off-by: Andrew Clayton <andrew@digital-domain.net> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-03-14Documentation: admin-guide: Fix typosTamara Diaconita1-1/+1
Fix typos in admin-guide directory. Make documentation clear and grammatically correct. Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-11-03Documentation/admin-guide: split the kernel parameter list to a separate fileJani Nikula1-4371/+3
Include the literal kernel parameter list from a separate file. This helps the pdf build. Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2016-10-27docs: Clean up and organize the admin guide a bitJonathan Corbet1-2/+2
The admin guide is a good start, but it's time to turn it into something better than an unordered blob of files. This is a first step in that direction. The TOC has been split up and annotated, the guides have been reordered, and minor tweaks have been applied to a few of them. One consequence of splitting up the TOC is that we don't really want to use :numbered: anymore, since the count resets every time and there doesn't seem to be a way to change that. Eventually we probably want to group the documents into sub-books, at which point we can go back to a single TOC, but it's probably early to do that. Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-10-24docs: fix locations of several documents that got movedMauro Carvalho Chehab1-3/+3
The previous patch renamed several files that are cross-referenced along the Kernel documentation. Adjust the links to point to the right places. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24docs-rst: create an user's manual bookMauro Carvalho Chehab1-0/+4577
Place README, REPORTING-BUGS, SecurityBugs and kernel-parameters on an user's manual book. As we'll be numbering the user's manual, remove the manual numbering from SecurityBugs. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>