This document is based on three recent lwn.net articles.
Some of the introductory material and linkage between articles
has been removed, and some time-based descriptions have been
revised.

Also all links to code have been removed as the code is very close by.

Contains corrections and improvements from Randy Dunlap <rdunlap@infradead.org>.
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add documentation on how to use slabinfo-gnuplot.sh script.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This patch fix some spelling typos in Documentation/ABI/stable.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The kernel NMI watchdog acts as both a hardlockup and softlockup detector.
However, the kernel parameter nmi_watchdog can only enable or disable the
hardlockup detector. Clarify that in the documentation.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Corrected Documentation/gpio/sysfs.txt for typos and wording.
typos: syfs -> sysfs, manges -> manages
wording: entry -> entries
Signed-off-by: Sachin Pandhare <sachinpandhare@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

On some places, people could use Private: to tag the private fields
of an struct. So, be case-insensitive when parsing "private:"
meta-tag.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The #kernelnewbies irc channel is no longer hosted on
irc.openprojects.net but on irc.oftc.net.
Removed pointer to different regional servers since oftc already uses
geo-IP load balancing.

The "description" quoted from the website no longer exists,
therefore removed the reference, quotes and carets.

The paragraph also contains a pointer to the kernelnewbies.org website.
Therefore changing the title to:
"Kernel Newbies IRC Channel and Website."
Signed-off-by: Richard Sailer <richard@weltraumpflege.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This patch fix spelling typos in Documentation/virtual/kvm.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

bc is mentioned lower in a dedicated section.
Yet it is useful to have all dependencies listed in
"Current Minimal Requirements" section.
Signed-off-by: Benoit Lemarchand <benoit.lemarchand@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Currently the encoding of documents generated by DocBook depends on
the current locale.  Make the output reproducible independently of
the locale, by setting the encoding to UTF-8 (LC_CTYPE=C.UTF-8) by
preference, or ASCII (LC_CTYPE=C) as a fallback.

LC_CTYPE can normally be overridden by LC_ALL, but the top-level
Makefile unsets that.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[jc: added check-lc_ctype to .gitignore]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

For years I've waited in vain for Linus to see the error of his ways and go
back to our beloved 2.6.x naming scheme.  But dispair has overtaken me at
last, so, with a heavy heart, I'm moving my repo to a more contemporary
name.  My kids will be proud of me.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

This form of the earlycon parameter was added by commit fb11ffe7
("of/fdt: add FDT serial scanning for earlycon") without documentation.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The examples should better match what kernel developers actually expect,
so that they set a good example both for this project and for other
projects with similar development processes.
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The gpiolib supports parsing DT properties of the form <function>-gpio
but it was only added for compatibility with older DT bindings that got
it wrong and should not be used in newer bindings.

The commit that added support for this was:

dd34c37a ("gpio: of: Allow -gpio suffix for property names")

but didn't update the documentation to explain this so it's been a source
of confusion. So let's make clear this in the GPIO documentation.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Just fix some typos in blkio-controller.txt, freezer-subsystem.txt,
unified-hierarchy.txt.
Signed-off-by: Yuan Sun <sunyuan3@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add document for how to install selftests.
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The nents argument to the DMA API functions operating on scatterlists is
always the same. The documentation used different argument names and the
matter was not mentioned in Documentation/DMA-API-HOWTO.txt at all. Fix
these.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

In commit 94fb9334 ("x86/crash: Allocate enough low memory when
crashkernel=high") the default value of crashkernel low memory
is changed to 256M. In this patch update it accordingly.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Several documentation changes.

First, we never mentioned any errors and never required any
error checks in documentation.

Second, mention that there is another way to configure and
manage zram devices -- zramctl, provided by util-linux.

Third, add a bit of clarification on why `mem_used_max' attr
is RW and correct some typos.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Pull spi fixes from Mark Brown:
 "A disappointingly large collection of fixes for SPI issues, though
  almost all in drivers (and there mainly the newly added Mediatek
  driver) and the core fixes are documentation and error handling.

  The driver fixes are all of the usual 'important if you see them'
  variety"

* tag 'spi-fix-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: xtensa-xtfpga: fix register endianness
  spi: meson: Fix module autoload for OF platform driver
  spi: mediatek: fix wrong error return value on probe
  spi: fix kernel-doc warnings in spi.h
  spi: spidev: fix possible NULL dereference
  spi: atmel: remove warning when !CONFIG_PM_SLEEP
  spi: bcm2835: BUG: fix wrong use of PAGE_MASK
  spi: mediatek: fix spi cs polarity error
  spi: Fix documentation of spi_alloc_master()
  spi: spi-pxa2xx: Check status register to determine if SSSR_TINT is disabled
  spi: Mediatek: Document devicetree bindings update for spi bus
  spi: mediatek: fix spi clock usage error
  spi: mediatek: remove clk_disable_unprepare()

Merge tag 'regulator-fix-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fixes from Mark Brown:
 "A collection of fixes that came in since I tagged the merge window
  pull request for v4.3:

   - Error handling fixes in the core

   - Fixes to a couple of TI drivers for device specific issues

   - Several fixes for module autoloading"

* tag 'regulator-fix-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: vexpress: Fix module autoload for OF platform driver
  regulator: gpio: Fix module autoload for OF platform driver
  regulator: anatop: Fix module autoload for OF platform driver
  regulator: core: Correct return value check in regulator_resolve_supply
  regulator: tps65218: Fix missing zero typo
  regulator: pbias: program pbias register offset in pbias driver
  regulator: core: fix possible NULL dereference

Pull device mapper fixes from Mike Snitzer:
 "Two stable@ fixes:

   - DM thinp fix to properly advertise discard support as disabled for
     thin devices backed by a thin-pool with discard support disabled.

   - DM crypt fix to prevent the creation of bios that violate the
     underlying block device's max_segments limits.  This fixes a
     relatively long-standing NCQ SSD corruption issue reported against
     dm-crypt ever since the dm-crypt cpu parallelization patches were
     merged back in 4.0"

* tag 'dm-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: constrain crypt device's max_segment_size to PAGE_SIZE
  dm thin: disable discard support for thin devices if pool's is disabled

Merge remote-tracking branches 'spi/fix/atmel', 'spi/fix/bcm2835', 'spi/fix/doc', 'spi/fix/mediatek', 'spi/fix/meson', 'spi/fix/mtk' and 'spi/fix/pxa2xx' into spi-linus

XTFPGA SPI controller has native endian registers.
Fix register acessors so that they work in big-endian configurations.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

Pull cgroup fixes from Tejun Heo:
 "The threadgroup locking changes which went in during 4.2 devel cycle
  added write locking of a percpu_rwsem in cgroup task migration path;
  unfortunately, that involved expedited rcu syncing which turned out to
  be too slow and heavy for certain workloads.  The patchset which is
  dependent on this one didn't get committed during that devel cycle, so
  these two patches can be reverted safely.

  Oleg reworked percpu_rwsem for 4.4 so that the writer path is a lot
  lighter.  The reported issue goes away with Oleg's reworked
  percpu_rwsem and I'll reapply these patches on the for-4.4 branch so
  that they can land together with Oleg's changes"

* 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"
  Revert "cgroup: simplify threadgroup locking"

Merge remote-tracking branches 'regulator/fix/anatop', 'regulator/fix/gpio', 'regulator/fix/pbias', 'regulator/fix/tpx65218' and 'regulator/fix/vexpress' into regulator-linus

Merge tag 'renesas-sh-drivers-for-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas

Pull SH drivers updates from Simon Horman:
 "I am sending this change after v4.3-rc1 has been released as it
  depends on SoC changes which are present in that rc release.

  Summary:

   - disable PM runtime for multi-platform ARM with genpd

   - disable legacy default PM Domain on emev2"

* tag 'renesas-sh-drivers-for-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  drivers: sh: Disable PM runtime for multi-platform ARM with genpd
  drivers: sh: Disable legacy default PM Domain on emev2

Pull s390 fixes from Martin Schwidefsky:
 "A couple of system call updates.  The two new system calls userfaultfd
  and membarrier have been added, as well as the 17 direct calls for the
  multiplexed socket system calls.

  In addition the system call compat wrappers have been flagged as
  notrace functions and a few wrappers could be removed.

  And bug fixes for the vector register handling, cpu_mf, suspend/resume,
  compat signals, SMT cputime accounting and the zfcp dumper"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: wire up separate socketcalls system calls
  s390/compat: remove superfluous compat wrappers
  s390/compat: do not trace compat wrapper functions
  s390/s390x: allocate sys_membarrier system call number
  s390/configs//zfcpdump_defconfig: Remove CONFIG_MEMSTICK
  s390: wire up userfaultfd system call
  s390/vtime: correct scaled cputime for SMT
  s390/cpum_cf: Corrected return code for unauthorized counter sets
  s390/compat: correct uc_sigmask of the compat signal frame
  s390: fix floating point register corruption
  s390/hibernate: fix save and restore of vector registers

Signed-off-by: Jann Horn <jann@thejh.net>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ARM fixes from Russell King:
 "Three fixes and a resulting cleanup for -rc2:

   - Andre Przywara reported that he was seeing a warning with the new
     cast inside DMA_ERROR_CODE's definition, and fixed the incorrect
     use.

   - Doug Anderson noticed that kgdb causes a "scheduling while atomic"
     bug.

   - OMAP5 folk noticed that their Thumb-2 compiled X servers crashed
     when enabling support to cover ARMv6 CPUs due to a kernel bug
     leaking some conditional context into the signal handler"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8425/1: kgdb: Don't try to stop the machine when setting breakpoints
  ARM: 8437/1: dma-mapping: fix build warning with new DMA_ERROR_CODE definition
  ARM: get rid of needless #if in signal handling code
  ARM: fix Thumb2 signal handling when ARMv6 is enabled

Merge tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest fixes from Shuah Khan:
 "This update contains 7 fixes for problems ranging from build failurs
  to incorrect error reporting"

* tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: exec: revert to default emit rule
  selftests: change install command to rsync
  selftests: mqueue: simplify the Makefile
  selftests: mqueue: allow extra cflags
  selftests: rename jump label to static_keys
  selftests/seccomp: add support for s390
  seltests/zram: fix syntax error

Pull power management and ACPI updates from Rafael Wysocki:
 "Included are: a somewhat late devfreq update which however is mostly
  fixes and cleanups with one new thing only (the PPMUv2 support on
  Exynos5433), an ACPI cpufreq driver fixup and two ACPI core cleanups
  related to preprocessor directives.

  Specifics:

   - Fix a memory allocation size in the devfreq core (Xiaolong Ye).

   - Fix a mistake in the exynos-ppmu DT binding (Javier Martinez
     Canillas).

   - Add support for PPMUv2 ((Platform Performance Monitoring Unit
     version 2.0) on the Exynos5433 SoCs (Chanwoo Choi).

   - Fix a type casting bug in the Exynos PPMU code (MyungJoo Ham).

   - Assorted devfreq code cleanups and optimizations (Javi Merino,
     MyungJoo Ham, Viresh Kumar).

   - Fix up the ACPI cpufreq driver to use a more lightweight way to get
     to its private data in the ->get() callback (Rafael J Wysocki).

   - Fix a CONFIG_ prefix bug in one of the ACPI drivers and make the
     ACPI subsystem use IS_ENABLED() instead of #ifdefs in function
     bodies (Sudeep Holla)"

* tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()
  ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()
  ACPI: int340x_thermal: add missing CONFIG_ prefix
  PM / devfreq: Fix incorrect type issue.
  PM / devfreq: tegra: Update governor to use devfreq_update_stats()
  PM / devfreq: comments for get_dev_status usage updated
  PM / devfreq: drop comment about thermal setting max_freq
  PM / devfreq: cache the last call to get_dev_status()
  PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
  PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
  PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
  PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
  PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding

Pull clk fixes from Stephen Boyd:
 "A few driver fixes for tegra, rockchip, and st SoCs and a two-liner in
  the framework to avoid oops when get_parent ops return out of range
  values on tegra platforms"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
  clk: check for invalid parent index of orphans in __clk_init()
  clk: tegra: dfll: Properly protect OPP list
  clk: rockchip: add critical clock for rk3368

Merge tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds

Pull LED fixes from Jacek Anaszewski:
 - fix module autoload for six OF platform drivers (aat1290, bcm6328,
   bcm6358, ktd2692, max77693, ns2)
 - aat1290: add missing static modifier
 - ipaq-micro: add missing LEDS_CLASS dependency
 - lp55xx: correct Kconfig dependecy for f/w user helper

* tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  leds:lp55xx: Correct Kconfig dependency for f/w user helper
  leds: leds-ipaq-micro: Add LEDS_CLASS dependency
  leds: aat1290: add 'static' modifier to init_mm_current_scale
  leds: leds-ns2: Fix module autoload for OF platform driver
  leds: max77693: Fix module autoload for OF platform driver
  leds: ktd2692: Fix module autoload for OF platform driver
  leds: bcm6358: Fix module autoload for OF platform driver
  leds: bcm6328: Fix module autoload for OF platform driver
  leds: aat1290: Fix module autoload for OF platform driver

Pull rdma fixes from Doug Ledford:
 "The new hfi1 driver in staging/rdma has had a number of fixup patches
  since being added to the tree.  This is the first batch of those fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/hfi: Properly set permissions for user device files
  IB/hfi1: mask vs shift confusion
  IB/hfi1: clean up some defines
  IB/hfi1: info leak in get_ctxt_info()
  IB/hfi1: fix a locking bug
  IB/hfi1: checking for NULL instead of IS_ERR
  IB/hfi1: fix sdma_descq_cnt parameter parsing
  IB/hfi1: fix copy_to/from_user() error handling
  IB/hfi1: fix pstateinfo from returning improperly byteswapped value