[PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

There are several UTF-8 characters at the Kernel's documentation.

Several of them were due to the process of converting files from
DocBook, LaTeX, HTML and Markdown. They were probably introduced
by the conversion tools used on that time.

Other UTF-8 characters were added along the time, but they're easily
replaceable by ASCII chars.

As Linux developers are all around the globe, and not everybody has UTF-8
as their default charset, better to use UTF-8 only on cases where it is really
needed.

The first 3 patches on this series were manually written, in order to solve
a few special cases.

The remaining patches on series address such cases on *.rst files and 
inside the Documentation/ABI, using this perl map table in order to do the
charset conversion:

my %char_map = (
	0x2010 => '-',		# HYPHEN
	0xad   => '-',		# SOFT HYPHEN
	0x2013 => '-',		# EN DASH
	0x2014 => '-',		# EM DASH

	0x2018 => "'",		# LEFT SINGLE QUOTATION MARK
	0x2019 => "'",		# RIGHT SINGLE QUOTATION MARK
	0xb4   => "'",		# ACUTE ACCENT

	0x201c => '"',		# LEFT DOUBLE QUOTATION MARK
	0x201d => '"',		# RIGHT DOUBLE QUOTATION MARK

	0x2212 => '-',		# MINUS SIGN
	0x2217 => '*',		# ASTERISK OPERATOR
	0xd7   => 'x',		# MULTIPLICATION SIGN

	0xbb   => '>',		# RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK

	0xa0   => ' ',		# NO-BREAK SPACE
	0xfeff => '',		# ZERO WIDTH NO-BREAK SPACE
);

After the conversion, those UTF-8 chars will be kept:

	- U+00a9 ('©'): COPYRIGHT SIGN
	- U+00ac ('¬'): NOT SIGN		# only at Documentation/powerpc/transactional_memory.rst
	- U+00ae ('®'): REGISTERED SIGN
	- U+00b0 ('°'): DEGREE SIGN
	- U+00b1 ('±'): PLUS-MINUS SIGN
	- U+00b2 ('²'): SUPERSCRIPT TWO
	- U+00b5 ('µ'): MICRO SIGN
	- U+00b7 ('·'): MIDDLE DOT		# See below
	- U+00bd ('½'): VULGAR FRACTION ONE HALF
	- U+00c7 ('Ç'): LATIN CAPITAL LETTER C WITH CEDILLA
	- U+00df ('ß'): LATIN SMALL LETTER SHARP S
	- U+00e1 ('á'): LATIN SMALL LETTER A WITH ACUTE
	- U+00e4 ('ä'): LATIN SMALL LETTER A WITH DIAERESIS
	- U+00e6 ('æ'): LATIN SMALL LETTER AE
	- U+00e7 ('ç'): LATIN SMALL LETTER C WITH CEDILLA
	- U+00e9 ('é'): LATIN SMALL LETTER E WITH ACUTE
	- U+00ea ('ê'): LATIN SMALL LETTER E WITH CIRCUMFLEX
	- U+00eb ('ë'): LATIN SMALL LETTER E WITH DIAERESIS
	- U+00f3 ('ó'): LATIN SMALL LETTER O WITH ACUTE
	- U+00f4 ('ô'): LATIN SMALL LETTER O WITH CIRCUMFLEX
	- U+00f6 ('ö'): LATIN SMALL LETTER O WITH DIAERESIS
	- U+00f8 ('ø'): LATIN SMALL LETTER O WITH STROKE
	- U+00fa ('ú'): LATIN SMALL LETTER U WITH ACUTE
	- U+00fc ('ü'): LATIN SMALL LETTER U WITH DIAERESIS
	- U+00fd ('ý'): LATIN SMALL LETTER Y WITH ACUTE
	- U+011f ('ğ'): LATIN SMALL LETTER G WITH BREVE
	- U+0142 ('ł'): LATIN SMALL LETTER L WITH STROKE
	- U+03bc ('μ'): GREEK SMALL LETTER MU
	- U+2026 ('…'): HORIZONTAL ELLIPSIS
	- U+2122 ('™'): TRADE MARK SIGN
	- U+2191 ('↑'): UPWARDS ARROW
	- U+2192 ('→'): RIGHTWARDS ARROW
	- U+2193 ('↓'): DOWNWARDS ARROW
	- U+2264 ('≤'): LESS-THAN OR EQUAL TO
	- U+2265 ('≥'): GREATER-THAN OR EQUAL TO
	- U+2500 ('─'): BOX DRAWINGS LIGHT HORIZONTAL
	- U+2502 ('│'): BOX DRAWINGS LIGHT VERTICAL
	- U+2514 ('└'): BOX DRAWINGS LIGHT UP AND RIGHT
	- U+251c ('├'): BOX DRAWINGS LIGHT VERTICAL AND RIGHT
	- U+2b0d ('⬍'): UP DOWN BLACK ARROW

PS.: maintainers were bcc on patch 00/53, in order to reduce the
risk of patch 00 to be rejected by list servers.

-

For U+00b7 ('·'): MIDDLE DOT, I opted to keep it on a few places:

- Documentation/devicetree/bindings/clock/qcom,rpmcc.txt

  As this file will be some day converted to yaml, where the 
  MIDDLE DOT will be removed, I guess it is not worth touching it.

- Documentation/scheduler/sched-deadline.rst

  There, it is used on a math expressions. So, better to keep.

- Documentation/devicetree/bindings/media/video-interface-devices.yaml

  There, it part of an ASCII artwork.

- translations/zh_CN

  I prefer not touching it, as it might have some special meaning in Simplified Chinese.

Mauro Carvalho Chehab (53):
  docs: cdrom-standard.rst: get rid of uneeded UTF-8 chars
  docs: ABI: remove a meaningless UTF-8 character
  docs: ABI: remove some spurious characters
  docs: index.rst: avoid using UTF-8 chars
  docs: hwmon: avoid using UTF-8 chars
  docs: admin-guide: avoid using UTF-8 chars
  docs: admin-guide: media: ipu3.rst: avoid using UTF-8 chars
  docs: admin-guide: sysctl: kernel.rst: avoid using UTF-8 chars
  docs: admin-guide: perf: imx-ddr.rst: avoid using UTF-8 chars
  docs: admin-guide: pm: avoid using UTF-8 chars
  docs: trace: coresight: coresight-etm4x-reference.rst: avoid using
    UTF-8 chars
  docs: driver-api: avoid using UTF-8 chars
  docs: driver-api: fpga: avoid using UTF-8 chars
  docs: driver-api: iio: avoid using UTF-8 chars
  docs: driver-api: thermal: avoid using UTF-8 chars
  docs: driver-api: media: drivers: avoid using UTF-8 chars
  docs: driver-api: firmware: other_interfaces.rst: avoid using UTF-8
    chars
  docs: driver-api: nvdimm: btt.rst: avoid using UTF-8 chars
  docs: fault-injection: nvme-fault-injection.rst: avoid using UTF-8
    chars
  docs: usb: avoid using UTF-8 chars
  docs: process: avoid using UTF-8 chars
  docs: block: data-integrity.rst: avoid using UTF-8 chars
  docs: userspace-api: media: fdl-appendix.rst: avoid using UTF-8 chars
  docs: userspace-api: media: v4l: avoid using UTF-8 chars
  docs: userspace-api: media: dvb: avoid using UTF-8 chars
  docs: vm: zswap.rst: avoid using UTF-8 chars
  docs: filesystems: f2fs.rst: avoid using UTF-8 chars
  docs: filesystems: ext4: avoid using UTF-8 chars
  docs: kernel-hacking: avoid using UTF-8 chars
  docs: hid: avoid using UTF-8 chars
  docs: security: tpm: avoid using UTF-8 chars
  docs: security: keys: trusted-encrypted.rst: avoid using UTF-8 chars
  docs: riscv: vm-layout.rst: avoid using UTF-8 chars
  docs: networking: scaling.rst: avoid using UTF-8 chars
  docs: networking: devlink: devlink-dpipe.rst: avoid using UTF-8 chars
  docs: networking: device_drivers: avoid using UTF-8 chars
  docs: x86: avoid using UTF-8 chars
  docs: scheduler: sched-deadline.rst: avoid using UTF-8 chars
  docs: dev-tools: testing-overview.rst: avoid using UTF-8 chars
  docs: power: powercap: powercap.rst: avoid using UTF-8 chars
  docs: ABI: avoid using UTF-8 chars
  docs: doc-guide: contributing.rst: avoid using UTF-8 chars
  docs: PCI: acpi-info.rst: avoid using UTF-8 chars
  docs: gpu: avoid using UTF-8 chars
  docs: sound: kernel-api: writing-an-alsa-driver.rst: avoid using UTF-8
    chars
  docs: arm64: arm-acpi.rst: avoid using UTF-8 chars
  docs: infiniband: tag_matching.rst: avoid using UTF-8 chars
  docs: timers: no_hz.rst: avoid using UTF-8 chars
  docs: misc-devices: ibmvmc.rst: avoid using UTF-8 chars
  docs: firmware-guide: acpi: lpit.rst: avoid using UTF-8 chars
  docs: firmware-guide: acpi: dsd: graph.rst: avoid using UTF-8 chars
  docs: virt: kvm: avoid using UTF-8 chars
  docs: RCU: avoid using UTF-8 chars

 .../obsolete/sysfs-kernel-fadump_registered   |   2 +-
 .../obsolete/sysfs-kernel-fadump_release_mem  |   2 +-
 ...sfs-class-chromeos-driver-cros-ec-lightbar |   2 +-
 .../ABI/testing/sysfs-class-net-cdc_ncm       |   2 +-
 .../ABI/testing/sysfs-devices-platform-ipmi   |   2 +-
 .../testing/sysfs-devices-platform-trackpoint |   2 +-
 Documentation/ABI/testing/sysfs-devices-soc   |   4 +-
 Documentation/ABI/testing/sysfs-module        |   4 +-
 Documentation/PCI/acpi-info.rst               |  26 +-
 .../Data-Structures/Data-Structures.rst       |  52 ++--
 .../Expedited-Grace-Periods.rst               |  40 +--
 .../Tree-RCU-Memory-Ordering.rst              |  10 +-
 .../RCU/Design/Requirements/Requirements.rst  | 126 ++++-----
 Documentation/admin-guide/index.rst           |   2 +-
 Documentation/admin-guide/media/ipu3.rst      |   2 +-
 Documentation/admin-guide/module-signing.rst  |   4 +-
 Documentation/admin-guide/perf/imx-ddr.rst    |   2 +-
 Documentation/admin-guide/pm/intel_idle.rst   |   4 +-
 Documentation/admin-guide/pm/intel_pstate.rst |   4 +-
 Documentation/admin-guide/ras.rst             |  94 +++----
 .../admin-guide/reporting-issues.rst          |  12 +-
 Documentation/admin-guide/sysctl/kernel.rst   |   2 +-
 Documentation/arm64/arm-acpi.rst              |   8 +-
 Documentation/block/data-integrity.rst        |   2 +-
 Documentation/cdrom/cdrom-standard.rst        |  30 +--
 Documentation/dev-tools/testing-overview.rst  |   4 +-
 Documentation/doc-guide/contributing.rst      |   2 +-
 .../driver-api/firmware/other_interfaces.rst  |   2 +-
 Documentation/driver-api/fpga/fpga-bridge.rst |  10 +-
 Documentation/driver-api/fpga/fpga-mgr.rst    |  12 +-
 .../driver-api/fpga/fpga-programming.rst      |   8 +-
 Documentation/driver-api/fpga/fpga-region.rst |  20 +-
 Documentation/driver-api/iio/buffers.rst      |   8 +-
 Documentation/driver-api/iio/hw-consumer.rst  |  10 +-
 .../driver-api/iio/triggered-buffers.rst      |   6 +-
 Documentation/driver-api/iio/triggers.rst     |  10 +-
 Documentation/driver-api/index.rst            |   2 +-
 Documentation/driver-api/ioctl.rst            |   8 +-
 .../media/drivers/sh_mobile_ceu_camera.rst    |   8 +-
 .../driver-api/media/drivers/vidtv.rst        |   4 +-
 .../driver-api/media/drivers/zoran.rst        |   2 +-
 Documentation/driver-api/nvdimm/btt.rst       |   2 +-
 .../driver-api/thermal/cpu-idle-cooling.rst   |  14 +-
 .../driver-api/thermal/intel_powerclamp.rst   |   6 +-
 .../thermal/x86_pkg_temperature_thermal.rst   |   2 +-
 .../fault-injection/nvme-fault-injection.rst  |   2 +-
 Documentation/filesystems/ext4/attributes.rst |  20 +-
 Documentation/filesystems/ext4/bigalloc.rst   |   6 +-
 Documentation/filesystems/ext4/blockgroup.rst |   8 +-
 Documentation/filesystems/ext4/blocks.rst     |   2 +-
 Documentation/filesystems/ext4/directory.rst  |  16 +-
 Documentation/filesystems/ext4/eainode.rst    |   2 +-
 Documentation/filesystems/ext4/inlinedata.rst |   6 +-
 Documentation/filesystems/ext4/inodes.rst     |   6 +-
 Documentation/filesystems/ext4/journal.rst    |   8 +-
 Documentation/filesystems/ext4/mmp.rst        |   2 +-
 .../filesystems/ext4/special_inodes.rst       |   4 +-
 Documentation/filesystems/ext4/super.rst      |  10 +-
 Documentation/filesystems/f2fs.rst            |   6 +-
 .../firmware-guide/acpi/dsd/graph.rst         |   2 +-
 Documentation/firmware-guide/acpi/lpit.rst    |   2 +-
 Documentation/gpu/i915.rst                    |   2 +-
 Documentation/gpu/komeda-kms.rst              |   2 +-
 Documentation/hid/hid-sensor.rst              |  70 ++---
 Documentation/hid/intel-ish-hid.rst           | 246 +++++++++---------
 Documentation/hwmon/ir36021.rst               |   2 +-
 Documentation/hwmon/ltc2992.rst               |   2 +-
 Documentation/hwmon/pm6764tr.rst              |   2 +-
 Documentation/hwmon/tmp103.rst                |   4 +-
 Documentation/index.rst                       |   4 +-
 Documentation/infiniband/tag_matching.rst     |   8 +-
 Documentation/kernel-hacking/hacking.rst      |   2 +-
 Documentation/kernel-hacking/locking.rst      |   2 +-
 Documentation/misc-devices/ibmvmc.rst         |   8 +-
 .../device_drivers/ethernet/intel/i40e.rst    |  12 +-
 .../device_drivers/ethernet/intel/iavf.rst    |   6 +-
 .../device_drivers/ethernet/netronome/nfp.rst |  12 +-
 .../networking/devlink/devlink-dpipe.rst      |   2 +-
 Documentation/networking/scaling.rst          |  18 +-
 Documentation/power/powercap/powercap.rst     | 210 +++++++--------
 Documentation/process/code-of-conduct.rst     |   2 +-
 .../process/kernel-enforcement-statement.rst  |   2 +-
 Documentation/riscv/vm-layout.rst             |   2 +-
 Documentation/scheduler/sched-deadline.rst    |   4 +-
 .../security/keys/trusted-encrypted.rst       |   4 +-
 Documentation/security/tpm/tpm_event_log.rst  |   2 +-
 Documentation/security/tpm/xen-tpmfront.rst   |   2 +-
 .../kernel-api/writing-an-alsa-driver.rst     |  68 ++---
 Documentation/timers/no_hz.rst                |   2 +-
 .../coresight/coresight-etm4x-reference.rst   |  16 +-
 Documentation/usb/ehci.rst                    |   2 +-
 Documentation/usb/gadget_printer.rst          |   2 +-
 Documentation/usb/mass-storage.rst            |  36 +--
 Documentation/usb/mtouchusb.rst               |   2 +-
 Documentation/usb/usb-serial.rst              |   2 +-
 .../media/dvb/audio-set-bypass-mode.rst       |   2 +-
 .../userspace-api/media/dvb/audio.rst         |   2 +-
 .../userspace-api/media/dvb/dmx-fopen.rst     |   2 +-
 .../userspace-api/media/dvb/dmx-fread.rst     |   2 +-
 .../media/dvb/dmx-set-filter.rst              |   2 +-
 .../userspace-api/media/dvb/intro.rst         |   6 +-
 .../userspace-api/media/dvb/video.rst         |   2 +-
 .../userspace-api/media/fdl-appendix.rst      |  64 ++---
 .../userspace-api/media/v4l/biblio.rst        |   8 +-
 .../userspace-api/media/v4l/crop.rst          |  16 +-
 .../userspace-api/media/v4l/dev-decoder.rst   |   6 +-
 .../userspace-api/media/v4l/diff-v4l.rst      |   2 +-
 .../userspace-api/media/v4l/open.rst          |   2 +-
 .../media/v4l/vidioc-cropcap.rst              |   4 +-
 Documentation/virt/kvm/api.rst                |  28 +-
 .../virt/kvm/running-nested-guests.rst        |  12 +-
 Documentation/vm/zswap.rst                    |   4 +-
 Documentation/x86/resctrl.rst                 |   2 +-
 Documentation/x86/sgx.rst                     |   4 +-
 114 files changed, 807 insertions(+), 807 deletions(-)

-- 
2.30.2

[PATCH 53/53] docs: RCU: avoid using UTF-8 chars

[Mauro Carvalho Chehab]

While UTF-8 characters can be used at the Linux documentation,
the best is to use them only when ASCII doesn't offer a good replacement.
So, replace the occurences of the following UTF-8 characters:

	- U+00a0 (' '): NO-BREAK SPACE
	- U+2013 ('–'): EN DASH
	- U+2014 ('—'): EM DASH
	- U+201c ('“'): LEFT DOUBLE QUOTATION MARK
	- U+201d ('”'): RIGHT DOUBLE QUOTATION MARK

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../Data-Structures/Data-Structures.rst       |  52 ++++----
 .../Expedited-Grace-Periods.rst               |  40 +++---
 .../Tree-RCU-Memory-Ordering.rst              |  10 +-
 .../RCU/Design/Requirements/Requirements.rst  | 126 +++++++++---------
 4 files changed, 114 insertions(+), 114 deletions(-)

diff --git a/Documentation/RCU/Design/Data-Structures/Data-Structures.rst b/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
index f4efd6897b09..e95c6c8eeb6a 100644
--- a/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
+++ b/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
@@ -301,7 +301,7 @@ The ``->gp_max`` field tracks the duration of the longest grace period
 in jiffies. It is protected by the root ``rcu_node``'s ``->lock``.
 
 The ``->name`` and ``->abbr`` fields distinguish between preemptible RCU
-(“rcu_preempt” and “p”) and non-preemptible RCU (“rcu_sched” and “s”).
+("rcu_preempt" and "p") and non-preemptible RCU ("rcu_sched" and "s").
 These fields are used for diagnostic and tracing purposes.
 
 The ``rcu_node`` Structure
@@ -456,21 +456,21 @@ expedited grace periods, respectively.
 | Lockless grace-period computation! Such a tantalizing possibility!    |
 | But consider the following sequence of events:                        |
 |                                                                       |
-| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
+| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
 |    wakes up, it notices that the current RCU grace period needs it to |
 |    report in, so it sets a flag where the scheduling clock interrupt  |
 |    will find it.                                                      |
-| #. Meanwhile, CPU 1 is running ``force_quiescent_state()``, and       |
-|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |
+| #. Meanwhile, CPU 1 is running ``force_quiescent_state()``, and       |
+|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |
 |    as an extended quiescent state.                                    |
-| #. CPU 0's scheduling clock interrupt fires in the middle of an RCU   |
+| #. CPU 0's scheduling clock interrupt fires in the middle of an RCU   |
 |    read-side critical section, and notices that the RCU core needs    |
 |    something, so commences RCU softirq processing.                    |
-| #. CPU 0's softirq handler executes and is just about ready to report |
+| #. CPU 0's softirq handler executes and is just about ready to report |
 |    its quiescent state up the ``rcu_node`` tree.                      |
-| #. But CPU 1 beats it to the punch, completing the current grace      |
+| #. But CPU 1 beats it to the punch, completing the current grace      |
 |    period and starting a new one.                                     |
-| #. CPU 0 now reports its quiescent state for the wrong grace period.  |
+| #. CPU 0 now reports its quiescent state for the wrong grace period.  |
 |    That grace period might now end before the RCU read-side critical  |
 |    section. If that happens, disaster will ensue.                     |
 |                                                                       |
@@ -515,18 +515,18 @@ removes itself from the ``->blkd_tasks`` list, then that task must
 advance the pointer to the next task on the list, or set the pointer to
 ``NULL`` if there are no subsequent tasks on the list.
 
-For example, suppose that tasks T1, T2, and T3 are all hard-affinitied
-to the largest-numbered CPU in the system. Then if task T1 blocked in an
+For example, suppose that tasks T1, T2, and T3 are all hard-affinitied
+to the largest-numbered CPU in the system. Then if task T1 blocked in an
 RCU read-side critical section, then an expedited grace period started,
-then task T2 blocked in an RCU read-side critical section, then a normal
-grace period started, and finally task 3 blocked in an RCU read-side
+then task T2 blocked in an RCU read-side critical section, then a normal
+grace period started, and finally task 3 blocked in an RCU read-side
 critical section, then the state of the last leaf ``rcu_node``
 structure's blocked-task list would be as shown below:
 
 .. kernel-figure:: blkd_task.svg
 
-Task T1 is blocking both grace periods, task T2 is blocking only the
-normal grace period, and task T3 is blocking neither grace period. Note
+Task T1 is blocking both grace periods, task T2 is blocking only the
+normal grace period, and task T3 is blocking neither grace period. Note
 that these tasks will not remove themselves from this list immediately
 upon resuming execution. They will instead remain on the list until they
 execute the outermost ``rcu_read_unlock()`` that ends their RCU
@@ -611,8 +611,8 @@ expressions as follows:
    66 #endif
 
 The maximum number of levels in the ``rcu_node`` structure is currently
-limited to four, as specified by lines 21-24 and the structure of the
-subsequent “if” statement. For 32-bit systems, this allows
+limited to four, as specified by lines 21-24 and the structure of the
+subsequent "if" statement. For 32-bit systems, this allows
 16*32*32*32=524,288 CPUs, which should be sufficient for the next few
 years at least. For 64-bit systems, 16*64*64*64=4,194,304 CPUs is
 allowed, which should see us through the next decade or so. This
@@ -638,9 +638,9 @@ fields. The number of CPUs per leaf ``rcu_node`` structure is therefore
 limited to 16 given the default value of ``CONFIG_RCU_FANOUT_LEAF``. If
 ``CONFIG_RCU_FANOUT_LEAF`` is unspecified, the value selected is based
 on the word size of the system, just as for ``CONFIG_RCU_FANOUT``.
-Lines 11-19 perform this computation.
+Lines 11-19 perform this computation.
 
-Lines 21-24 compute the maximum number of CPUs supported by a
+Lines 21-24 compute the maximum number of CPUs supported by a
 single-level (which contains a single ``rcu_node`` structure),
 two-level, three-level, and four-level ``rcu_node`` tree, respectively,
 given the fanout specified by ``RCU_FANOUT`` and ``RCU_FANOUT_LEAF``.
@@ -649,18 +649,18 @@ These numbers of CPUs are retained in the ``RCU_FANOUT_1``,
 variables, respectively.
 
 These variables are used to control the C-preprocessor ``#if`` statement
-spanning lines 26-66 that computes the number of ``rcu_node`` structures
+spanning lines 26-66 that computes the number of ``rcu_node`` structures
 required for each level of the tree, as well as the number of levels
 required. The number of levels is placed in the ``NUM_RCU_LVLS``
-C-preprocessor variable by lines 27, 35, 44, and 54. The number of
+C-preprocessor variable by lines 27, 35, 44, and 54. The number of
 ``rcu_node`` structures for the topmost level of the tree is always
 exactly one, and this value is unconditionally placed into
-``NUM_RCU_LVL_0`` by lines 28, 36, 45, and 55. The rest of the levels
+``NUM_RCU_LVL_0`` by lines 28, 36, 45, and 55. The rest of the levels
 (if any) of the ``rcu_node`` tree are computed by dividing the maximum
 number of CPUs by the fanout supported by the number of levels from the
 current level down, rounding up. This computation is performed by
-lines 37, 46-47, and 56-58. Lines 31-33, 40-42, 50-52, and 62-63 create
-initializers for lockdep lock-class names. Finally, lines 64-66 produce
+lines 37, 46-47, and 56-58. Lines 31-33, 40-42, 50-52, and 62-63 create
+initializers for lockdep lock-class names. Finally, lines 64-66 produce
 an error if the maximum number of CPUs is too large for the specified
 fanout.
 
@@ -716,13 +716,13 @@ In this figure, the ``->head`` pointer references the first RCU callback
 in the list. The ``->tails[RCU_DONE_TAIL]`` array element references the
 ``->head`` pointer itself, indicating that none of the callbacks is
 ready to invoke. The ``->tails[RCU_WAIT_TAIL]`` array element references
-callback CB 2's ``->next`` pointer, which indicates that CB 1 and CB 2
+callback CB 2's ``->next`` pointer, which indicates that CB 1 and CB 2
 are both waiting on the current grace period, give or take possible
 disagreements about exactly which grace period is the current one. The
 ``->tails[RCU_NEXT_READY_TAIL]`` array element references the same RCU
 callback that ``->tails[RCU_WAIT_TAIL]`` does, which indicates that
 there are no callbacks waiting on the next RCU grace period. The
-``->tails[RCU_NEXT_TAIL]`` array element references CB 4's ``->next``
+``->tails[RCU_NEXT_TAIL]`` array element references CB 4's ``->next``
 pointer, indicating that all the remaining RCU callbacks have not yet
 been assigned to an RCU grace period. Note that the
 ``->tails[RCU_NEXT_TAIL]`` array element always references the last RCU
@@ -1031,7 +1031,7 @@ field to record the offset of the ``rcu_head`` structure within the
 enclosing RCU-protected data structure.
 
 Both of these fields are used internally by RCU. From the viewpoint of
-RCU users, this structure is an opaque “cookie”.
+RCU users, this structure is an opaque "cookie".
 
 +-----------------------------------------------------------------------+
 | **Quick Quiz**:                                                       |
diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
index 6f89cf1e567d..742921a7532b 100644
--- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
+++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
@@ -304,8 +304,8 @@ representing the elements of the ``->exp_wq[]`` array.
 
 .. kernel-figure:: Funnel0.svg
 
-The next diagram shows the situation after the arrival of Task A and
-Task B at the leftmost and rightmost leaf ``rcu_node`` structures,
+The next diagram shows the situation after the arrival of Task A and
+Task B at the leftmost and rightmost leaf ``rcu_node`` structures,
 respectively. The current value of the ``rcu_state`` structure's
 ``->expedited_sequence`` field is zero, so adding three and clearing the
 bottom bit results in the value two, which both tasks record in the
@@ -313,13 +313,13 @@ bottom bit results in the value two, which both tasks record in the
 
 .. kernel-figure:: Funnel1.svg
 
-Each of Tasks A and B will move up to the root ``rcu_node`` structure.
-Suppose that Task A wins, recording its desired grace-period sequence
+Each of Tasks A and B will move up to the root ``rcu_node`` structure.
+Suppose that Task A wins, recording its desired grace-period sequence
 number and resulting in the state shown below:
 
 .. kernel-figure:: Funnel2.svg
 
-Task A now advances to initiate a new grace period, while Task B moves
+Task A now advances to initiate a new grace period, while Task B moves
 up to the root ``rcu_node`` structure, and, seeing that its desired
 sequence number is already recorded, blocks on ``->exp_wq[1]``.
 
@@ -340,7 +340,7 @@ sequence number is already recorded, blocks on ``->exp_wq[1]``.
 | ``->exp_wq[1]``.                                                      |
 +-----------------------------------------------------------------------+
 
-If Tasks C and D also arrive at this point, they will compute the same
+If Tasks C and D also arrive at this point, they will compute the same
 desired grace-period sequence number, and see that both leaf
 ``rcu_node`` structures already have that value recorded. They will
 therefore block on their respective ``rcu_node`` structures'
@@ -348,52 +348,52 @@ therefore block on their respective ``rcu_node`` structures'
 
 .. kernel-figure:: Funnel3.svg
 
-Task A now acquires the ``rcu_state`` structure's ``->exp_mutex`` and
+Task A now acquires the ``rcu_state`` structure's ``->exp_mutex`` and
 initiates the grace period, which increments ``->expedited_sequence``.
-Therefore, if Tasks E and F arrive, they will compute a desired sequence
+Therefore, if Tasks E and F arrive, they will compute a desired sequence
 number of 4 and will record this value as shown below:
 
 .. kernel-figure:: Funnel4.svg
 
-Tasks E and F will propagate up the ``rcu_node`` combining tree, with
-Task F blocking on the root ``rcu_node`` structure and Task E wait for
-Task A to finish so that it can start the next grace period. The
+Tasks E and F will propagate up the ``rcu_node`` combining tree, with
+Task F blocking on the root ``rcu_node`` structure and Task E wait for
+Task A to finish so that it can start the next grace period. The
 resulting state is as shown below:
 
 .. kernel-figure:: Funnel5.svg
 
-Once the grace period completes, Task A starts waking up the tasks
+Once the grace period completes, Task A starts waking up the tasks
 waiting for this grace period to complete, increments the
 ``->expedited_sequence``, acquires the ``->exp_wake_mutex`` and then
 releases the ``->exp_mutex``. This results in the following state:
 
 .. kernel-figure:: Funnel6.svg
 
-Task E can then acquire ``->exp_mutex`` and increment
-``->expedited_sequence`` to the value three. If new tasks G and H arrive
+Task E can then acquire ``->exp_mutex`` and increment
+``->expedited_sequence`` to the value three. If new tasks G and H arrive
 and moves up the combining tree at the same time, the state will be as
 follows:
 
 .. kernel-figure:: Funnel7.svg
 
 Note that three of the root ``rcu_node`` structure's waitqueues are now
-occupied. However, at some point, Task A will wake up the tasks blocked
+occupied. However, at some point, Task A will wake up the tasks blocked
 on the ``->exp_wq`` waitqueues, resulting in the following state:
 
 .. kernel-figure:: Funnel8.svg
 
-Execution will continue with Tasks E and H completing their grace
+Execution will continue with Tasks E and H completing their grace
 periods and carrying out their wakeups.
 
 +-----------------------------------------------------------------------+
 | **Quick Quiz**:                                                       |
 +-----------------------------------------------------------------------+
-| What happens if Task A takes so long to do its wakeups that Task E's  |
+| What happens if Task A takes so long to do its wakeups that Task E's  |
 | grace period completes?                                               |
 +-----------------------------------------------------------------------+
 | **Answer**:                                                           |
 +-----------------------------------------------------------------------+
-| Then Task E will block on the ``->exp_wake_mutex``, which will also   |
+| Then Task E will block on the ``->exp_wake_mutex``, which will also   |
 | prevent it from releasing ``->exp_mutex``, which in turn will prevent |
 | the next grace period from starting. This last is important in        |
 | preventing overflow of the ``->exp_wq[]`` array.                      |
@@ -464,8 +464,8 @@ code need not worry about POSIX signals. Unfortunately, it has the
 corresponding disadvantage that workqueues cannot be used until they are
 initialized, which does not happen until some time after the scheduler
 spawns the first task. Given that there are parts of the kernel that
-really do want to execute grace periods during this mid-boot “dead
-zone”, expedited grace periods must do something else during thie time.
+really do want to execute grace periods during this mid-boot "dead
+zone", expedited grace periods must do something else during thie time.
 
 What they do is to fall back to the old practice of requiring that the
 requesting task drive the expedited grace period, as was the case before
diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
index a648b423ba0e..d76c6bfdc659 100644
--- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
+++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
@@ -215,7 +215,7 @@ newly arrived RCU callbacks against future grace periods:
    43 }
 
 But the only part of ``rcu_prepare_for_idle()`` that really matters for
-this discussion are lines 37–39. We will therefore abbreviate this
+this discussion are lines 37-39. We will therefore abbreviate this
 function as follows:
 
 .. kernel-figure:: rcu_node-lock.svg
@@ -418,7 +418,7 @@ wait on.
 | It is indeed not necessary for the grace period to wait on such a     |
 | critical section. However, it is permissible to wait on it. And it is |
 | furthermore important to wait on it, as this lazy approach is far     |
-| more scalable than a “big bang” all-at-once grace-period start could  |
+| more scalable than a "big bang" all-at-once grace-period start could  |
 | possibly be.                                                          |
 +-----------------------------------------------------------------------+
 
@@ -448,7 +448,7 @@ proceeds upwards from that point, and the ``rcu_node`` ``->lock``
 guarantees that the first CPU's quiescent state happens before the
 remainder of the second CPU's traversal. Applying this line of thought
 repeatedly shows that all CPUs' quiescent states happen before the last
-CPU traverses through the root ``rcu_node`` structure, the “last CPU”
+CPU traverses through the root ``rcu_node`` structure, the "last CPU"
 being the one that clears the last bit in the root ``rcu_node``
 structure's ``->qsmask`` field.
 
@@ -501,8 +501,8 @@ Forcing Quiescent States
 
 As noted above, idle and offline CPUs cannot report their own quiescent
 states, and therefore the grace-period kernel thread must do the
-reporting on their behalf. This process is called “forcing quiescent
-states”, it is repeated every few jiffies, and its ordering effects are
+reporting on their behalf. This process is called "forcing quiescent
+states", it is repeated every few jiffies, and its ordering effects are
 shown below:
 
 .. kernel-figure:: TreeRCU-gp-fqs.svg
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
index 38a39476fc24..a3493b34f3dd 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.rst
+++ b/Documentation/RCU/Design/Requirements/Requirements.rst
@@ -4,7 +4,7 @@ A Tour Through RCU's Requirements
 
 Copyright IBM Corporation, 2015
 
-Author: Paul E. McKenney
+Author: Paul E. McKenney
 
 The initial version of this document appeared in the
 `LWN <https://lwn.net/>`_ on those articles:
@@ -66,7 +66,7 @@ Grace-Period Guarantee
 
 RCU's grace-period guarantee is unusual in being premeditated: Jack
 Slingwine and I had this guarantee firmly in mind when we started work
-on RCU (then called “rclock”) in the early 1990s. That said, the past
+on RCU (then called "rclock") in the early 1990s. That said, the past
 two decades of experience with RCU have produced a much more detailed
 understanding of this guarantee.
 
@@ -102,7 +102,7 @@ overhead to readers, for example:
       15   WRITE_ONCE(y, 1);
       16 }
 
-Because the synchronize_rcu() on line 14 waits for all pre-existing
+Because the synchronize_rcu() on line 14 waits for all pre-existing
 readers, any instance of thread0() that loads a value of zero from
 ``x`` must complete before thread1() stores to ``y``, so that
 instance must also load a value of zero from ``y``. Similarly, any
@@ -178,7 +178,7 @@ little or no synchronization overhead in do_something_dlm().
 +-----------------------------------------------------------------------+
 | **Quick Quiz**:                                                       |
 +-----------------------------------------------------------------------+
-| Why is the synchronize_rcu() on line 28 needed?                       |
+| Why is the synchronize_rcu() on line 28 needed?                       |
 +-----------------------------------------------------------------------+
 | **Answer**:                                                           |
 +-----------------------------------------------------------------------+
@@ -244,7 +244,7 @@ their rights to reorder this code as follows:
       16 }
 
 If an RCU reader fetches ``gp`` just after ``add_gp_buggy_optimized``
-executes line 11, it will see garbage in the ``->a`` and ``->b`` fields.
+executes line 11, it will see garbage in the ``->a`` and ``->b`` fields.
 And this is but one of many ways in which compiler and hardware
 optimizations could cause trouble. Therefore, we clearly need some way
 to prevent the compiler and the CPU from reordering in this manner,
@@ -279,11 +279,11 @@ shows an example of insertion:
       15   return true;
       16 }
 
-The rcu_assign_pointer() on line 13 is conceptually equivalent to a
+The rcu_assign_pointer() on line 13 is conceptually equivalent to a
 simple assignment statement, but also guarantees that its assignment
-will happen after the two assignments in lines 11 and 12, similar to the
+will happen after the two assignments in lines 11 and 12, similar to the
 C11 ``memory_order_release`` store operation. It also prevents any
-number of “interesting” compiler optimizations, for example, the use of
+number of "interesting" compiler optimizations, for example, the use of
 ``gp`` as a scratch location immediately preceding the assignment.
 
 +-----------------------------------------------------------------------+
@@ -410,11 +410,11 @@ This process is implemented by remove_gp_synchronous():
       15   return true;
       16 }
 
-This function is straightforward, with line 13 waiting for a grace
-period before line 14 frees the old data element. This waiting ensures
-that readers will reach line 7 of do_something_gp() before the data
+This function is straightforward, with line 13 waiting for a grace
+period before line 14 frees the old data element. This waiting ensures
+that readers will reach line 7 of do_something_gp() before the data
 element referenced by ``p`` is freed. The rcu_access_pointer() on
-line 6 is similar to rcu_dereference(), except that:
+line 6 is similar to rcu_dereference(), except that:
 
 #. The value returned by rcu_access_pointer() cannot be
    dereferenced. If you want to access the value pointed to as well as
@@ -488,25 +488,25 @@ systems with more than one CPU:
    section ends and the time that synchronize_rcu() returns. Without
    this guarantee, a pre-existing RCU read-side critical section might
    hold a reference to the newly removed ``struct foo`` after the
-   kfree() on line 14 of remove_gp_synchronous().
+   kfree() on line 14 of remove_gp_synchronous().
 #. Each CPU that has an RCU read-side critical section that ends after
    synchronize_rcu() returns is guaranteed to execute a full memory
    barrier between the time that synchronize_rcu() begins and the
    time that the RCU read-side critical section begins. Without this
    guarantee, a later RCU read-side critical section running after the
-   kfree() on line 14 of remove_gp_synchronous() might later run
+   kfree() on line 14 of remove_gp_synchronous() might later run
    do_something_gp() and find the newly deleted ``struct foo``.
 #. If the task invoking synchronize_rcu() remains on a given CPU,
    then that CPU is guaranteed to execute a full memory barrier sometime
    during the execution of synchronize_rcu(). This guarantee ensures
-   that the kfree() on line 14 of remove_gp_synchronous() really
-   does execute after the removal on line 11.
+   that the kfree() on line 14 of remove_gp_synchronous() really
+   does execute after the removal on line 11.
 #. If the task invoking synchronize_rcu() migrates among a group of
    CPUs during that invocation, then each of the CPUs in that group is
    guaranteed to execute a full memory barrier sometime during the
    execution of synchronize_rcu(). This guarantee also ensures that
-   the kfree() on line 14 of remove_gp_synchronous() really does
-   execute after the removal on line 11, but also in the case where the
+   the kfree() on line 14 of remove_gp_synchronous() really does
+   execute after the removal on line 11, but also in the case where the
    thread executing the synchronize_rcu() migrates in the meantime.
 
 +-----------------------------------------------------------------------+
@@ -525,8 +525,8 @@ systems with more than one CPU:
 | In other words, a given instance of synchronize_rcu() can avoid       |
 | waiting on a given RCU read-side critical section only if it can      |
 | prove that synchronize_rcu() started first.                           |
-| A related question is “When rcu_read_lock() doesn't generate any      |
-| code, why does it matter how it relates to a grace period?” The       |
+| A related question is "When rcu_read_lock() doesn't generate any      |
+| code, why does it matter how it relates to a grace period?" The       |
 | answer is that it is not the relationship of rcu_read_lock()          |
 | itself that is important, but rather the relationship of the code     |
 | within the enclosed RCU read-side critical section to the code        |
@@ -538,7 +538,7 @@ systems with more than one CPU:
 | of any access following the grace period.                             |
 |                                                                       |
 | As of late 2016, mathematical models of RCU take this viewpoint, for  |
-| example, see slides 62 and 63 of the `2016 LinuxCon                   |
+| example, see slides 62 and 63 of the `2016 LinuxCon                   |
 | EU <http://www2.rdrop.com/users/paulmck/scalability/paper/LinuxMM.201 |
 | 6.10.04c.LCE.pdf>`__                                                  |
 | presentation.                                                         |
@@ -584,9 +584,9 @@ systems with more than one CPU:
 |                                                                       |
 | And similarly, without a memory barrier between the beginning of the  |
 | grace period and the beginning of the RCU read-side critical section, |
-| CPU 1 might end up accessing the freelist.                            |
+| CPU 1 might end up accessing the freelist.                            |
 |                                                                       |
-| The “as if” rule of course applies, so that any implementation that   |
+| The "as if" rule of course applies, so that any implementation that   |
 | acts as if the appropriate memory barriers were in place is a correct |
 | implementation. That said, it is much easier to fool yourself into    |
 | believing that you have adhered to the as-if rule than it is to       |
@@ -1002,7 +1002,7 @@ RCU implementation must abide by them. They therefore bear repeating:
    ECC errors, NMIs, and other hardware events. Although a delay of more
    than about 20 seconds can result in splats, the RCU implementation is
    obligated to use algorithms that can tolerate extremely long delays,
-   but where “extremely long” is not long enough to allow wrap-around
+   but where "extremely long" is not long enough to allow wrap-around
    when incrementing a 64-bit counter.
 #. Both the compiler and the CPU can reorder memory accesses. Where it
    matters, RCU must use compiler directives and memory-barrier
@@ -1169,7 +1169,7 @@ Energy efficiency is a critical component of performance today, and
 Linux-kernel RCU implementations must therefore avoid unnecessarily
 awakening idle CPUs. I cannot claim that this requirement was
 premeditated. In fact, I learned of it during a telephone conversation
-in which I was given “frank and open” feedback on the importance of
+in which I was given "frank and open" feedback on the importance of
 energy efficiency in battery-powered systems and on specific
 energy-efficiency shortcomings of the Linux-kernel RCU implementation.
 In my experience, the battery-powered embedded community will consider
@@ -1234,7 +1234,7 @@ requirements: A storm of synchronize_rcu_expedited() invocations on
 4096 CPUs should at least make reasonable forward progress. In return
 for its shorter latencies, synchronize_rcu_expedited() is permitted
 to impose modest degradation of real-time latency on non-idle online
-CPUs. Here, “modest” means roughly the same latency degradation as a
+CPUs. Here, "modest" means roughly the same latency degradation as a
 scheduling-clock interrupt.
 
 There are a number of situations where even
@@ -1274,8 +1274,8 @@ be used in place of synchronize_rcu() as follows:
       28 }
 
 A definition of ``struct foo`` is finally needed, and appears on
-lines 1-5. The function remove_gp_cb() is passed to call_rcu()
-on line 25, and will be invoked after the end of a subsequent grace
+lines 1-5. The function remove_gp_cb() is passed to call_rcu()
+on line 25, and will be invoked after the end of a subsequent grace
 period. This gets the same effect as remove_gp_synchronous(), but
 without forcing the updater to wait for a grace period to elapse. The
 call_rcu() function may be used in a number of situations where
@@ -1294,23 +1294,23 @@ threads or (in the Linux kernel) workqueues.
 +-----------------------------------------------------------------------+
 | **Quick Quiz**:                                                       |
 +-----------------------------------------------------------------------+
-| Why does line 19 use rcu_access_pointer()? After all,                 |
-| call_rcu() on line 25 stores into the structure, which would          |
+| Why does line 19 use rcu_access_pointer()? After all,                 |
+| call_rcu() on line 25 stores into the structure, which would          |
 | interact badly with concurrent insertions. Doesn't this mean that     |
 | rcu_dereference() is required?                                        |
 +-----------------------------------------------------------------------+
 | **Answer**:                                                           |
 +-----------------------------------------------------------------------+
-| Presumably the ``->gp_lock`` acquired on line 18 excludes any         |
+| Presumably the ``->gp_lock`` acquired on line 18 excludes any         |
 | changes, including any insertions that rcu_dereference() would        |
 | protect against. Therefore, any insertions will be delayed until      |
-| after ``->gp_lock`` is released on line 25, which in turn means that  |
+| after ``->gp_lock`` is released on line 25, which in turn means that  |
 | rcu_access_pointer() suffices.                                        |
 +-----------------------------------------------------------------------+
 
 However, all that remove_gp_cb() is doing is invoking kfree() on
 the data element. This is a common idiom, and is supported by
-kfree_rcu(), which allows “fire and forget” operation as shown
+kfree_rcu(), which allows "fire and forget" operation as shown
 below:
 
    ::
@@ -1396,8 +1396,8 @@ may be used for this purpose, as shown below:
       18   return true;
       19 }
 
-On line 14, get_state_synchronize_rcu() obtains a “cookie” from RCU,
-then line 15 carries out other tasks, and finally, line 16 returns
+On line 14, get_state_synchronize_rcu() obtains a "cookie" from RCU,
+then line 15 carries out other tasks, and finally, line 16 returns
 immediately if a grace period has elapsed in the meantime, but otherwise
 waits as required. The need for ``get_state_synchronize_rcu`` and
 cond_synchronize_rcu() has appeared quite recently, so it is too
@@ -1420,9 +1420,9 @@ example, an infinite loop in an RCU read-side critical section must by
 definition prevent later grace periods from ever completing. For a more
 involved example, consider a 64-CPU system built with
 ``CONFIG_RCU_NOCB_CPU=y`` and booted with ``rcu_nocbs=1-63``, where
-CPUs 1 through 63 spin in tight loops that invoke call_rcu(). Even
+CPUs 1 through 63 spin in tight loops that invoke call_rcu(). Even
 if these tight loops also contain calls to cond_resched() (thus
-allowing grace periods to complete), CPU 0 simply will not be able to
+allowing grace periods to complete), CPU 0 simply will not be able to
 invoke callbacks as fast as the other 63 CPUs can register them, at
 least not until the system runs out of memory. In both of these
 examples, the Spiderman principle applies: With great power comes great
@@ -1433,7 +1433,7 @@ callbacks.
 RCU takes the following steps to encourage timely completion of grace
 periods:
 
-#. If a grace period fails to complete within 100 milliseconds, RCU
+#. If a grace period fails to complete within 100 milliseconds, RCU
    causes future invocations of cond_resched() on the holdout CPUs
    to provide an RCU quiescent state. RCU also causes those CPUs'
    need_resched() invocations to return ``true``, but only after the
@@ -1442,12 +1442,12 @@ periods:
    indefinitely in the kernel without scheduling-clock interrupts, which
    defeats the above need_resched() strategem. RCU will therefore
    invoke resched_cpu() on any ``nohz_full`` CPUs still holding out
-   after 109 milliseconds.
+   after 109 milliseconds.
 #. In kernels built with ``CONFIG_RCU_BOOST=y``, if a given task that
    has been preempted within an RCU read-side critical section is
-   holding out for more than 500 milliseconds, RCU will resort to
+   holding out for more than 500 milliseconds, RCU will resort to
    priority boosting.
-#. If a CPU is still holding out 10 seconds into the grace period, RCU
+#. If a CPU is still holding out 10 seconds into the grace period, RCU
    will invoke resched_cpu() on it regardless of its ``nohz_full``
    state.
 
@@ -1579,7 +1579,7 @@ period.
 Software-Engineering Requirements
 ---------------------------------
 
-Between Murphy's Law and “To err is human”, it is necessary to guard
+Between Murphy's Law and "To err is human", it is necessary to guard
 against mishaps and misuse:
 
 #. It is all too easy to forget to use rcu_read_lock() everywhere
@@ -1626,7 +1626,7 @@ against mishaps and misuse:
    `patch <https://lore.kernel.org/r/20100319013024.GA28456@Krystal>`__.
 #. An infinite loop in an RCU read-side critical section will eventually
    trigger an RCU CPU stall warning splat, with the duration of
-   “eventually” being controlled by the ``RCU_CPU_STALL_TIMEOUT``
+   "eventually" being controlled by the ``RCU_CPU_STALL_TIMEOUT``
    ``Kconfig`` option, or, alternatively, by the
    ``rcupdate.rcu_cpu_stall_timeout`` boot/sysfs parameter. However, RCU
    is not obligated to produce this splat unless there is a grace period
@@ -1704,7 +1704,7 @@ Configuration
 
 RCU's goal is automatic configuration, so that almost nobody needs to
 worry about RCU's ``Kconfig`` options. And for almost all users, RCU
-does in fact work well “out of the box.”
+does in fact work well "out of the box."
 
 However, there are specialized use cases that are handled by kernel boot
 parameters and ``Kconfig`` options. Unfortunately, the ``Kconfig``
@@ -1733,7 +1733,7 @@ listings.
 
 RCU must therefore wait for a given CPU to actually come online before
 it can allow itself to believe that the CPU actually exists. The
-resulting “ghost CPUs” (which are never going to come online) cause a
+resulting "ghost CPUs" (which are never going to come online) cause a
 number of `interesting
 complications <https://paulmck.livejournal.com/37494.html>`__.
 
@@ -1789,7 +1789,7 @@ normally.
 | **Answer**:                                                           |
 +-----------------------------------------------------------------------+
 | Very carefully!                                                       |
-| During the “dead zone” between the time that the scheduler spawns the |
+| During the "dead zone" between the time that the scheduler spawns the |
 | first task and the time that all of RCU's kthreads have been spawned, |
 | all synchronous grace periods are handled by the expedited            |
 | grace-period mechanism. At runtime, this expedited mechanism relies   |
@@ -1824,7 +1824,7 @@ Some Linux-kernel architectures can enter an interrupt handler from
 non-idle process context, and then just never leave it, instead
 stealthily transitioning back to process context. This trick is
 sometimes used to invoke system calls from inside the kernel. These
-“half-interrupts” mean that RCU has to be very careful about how it
+"half-interrupts" mean that RCU has to be very careful about how it
 counts interrupt nesting levels. I learned of this requirement the hard
 way during a rewrite of RCU's dyntick-idle code.
 
@@ -1921,7 +1921,7 @@ and go. It is of course illegal to use any RCU API member from an
 offline CPU, with the exception of `SRCU <Sleepable RCU_>`__ read-side
 critical sections. This requirement was present from day one in
 DYNIX/ptx, but on the other hand, the Linux kernel's CPU-hotplug
-implementation is “interesting.”
+implementation is "interesting."
 
 The Linux-kernel CPU-hotplug implementation has notifiers that are used
 to allow the various kernel subsystems (including RCU) to respond
@@ -2268,7 +2268,7 @@ remain zero during all phases of grace-period processing, and that bit
 happens to map to the bottom bit of the ``rcu_head`` structure's
 ``->next`` field. RCU makes this guarantee as long as call_rcu() is
 used to post the callback, as opposed to kfree_rcu() or some future
-“lazy” variant of call_rcu() that might one day be created for
+"lazy" variant of call_rcu() that might one day be created for
 energy-efficiency purposes.
 
 That said, there are limits. RCU requires that the ``rcu_head``
@@ -2281,7 +2281,7 @@ architecture provides only two-byte alignment, and thus acts as
 alignment's least common denominator.
 
 The reason for reserving the bottom bit of pointers to ``rcu_head``
-structures is to leave the door open to “lazy” callbacks whose
+structures is to leave the door open to "lazy" callbacks whose
 invocations can safely be deferred. Deferring invocation could
 potentially have energy-efficiency benefits, but only if the rate of
 non-lazy callbacks decreases significantly for some important workload.
@@ -2354,8 +2354,8 @@ which in practice also means that RCU must have an aggressive
 stress-test suite. This stress-test suite is called ``rcutorture``.
 
 Although the need for ``rcutorture`` was no surprise, the current
-immense popularity of the Linux kernel is posing interesting—and perhaps
-unprecedented—validation challenges. To see this, keep in mind that
+immense popularity of the Linux kernel is posing interesting-and perhaps
+unprecedented-validation challenges. To see this, keep in mind that
 there are well over one billion instances of the Linux kernel running
 today, given Android smartphones, Linux-powered televisions, and
 servers. This number can be expected to increase sharply with the advent
@@ -2399,7 +2399,7 @@ single flavor. The read-side API remains, and continues to disable
 softirq and to be accounted for by lockdep. Much of the material in this
 section is therefore strictly historical in nature.
 
-The softirq-disable (AKA “bottom-half”, hence the “_bh” abbreviations)
+The softirq-disable (AKA "bottom-half", hence the "_bh" abbreviations)
 flavor of RCU, or *RCU-bh*, was developed by Dipankar Sarma to provide a
 flavor of RCU that could withstand the network-based denial-of-service
 attacks researched by Robert Olsson. These attacks placed so much
@@ -2458,7 +2458,7 @@ effect of also waiting for all pre-existing interrupt and NMI handlers.
 However, there are legitimate preemptible-RCU implementations that do
 not have this property, given that any point in the code outside of an
 RCU read-side critical section can be a quiescent state. Therefore,
-*RCU-sched* was created, which follows “classic” RCU in that an
+*RCU-sched* was created, which follows "classic" RCU in that an
 RCU-sched grace period waits for pre-existing interrupt and NMI
 handlers. In kernels built with ``CONFIG_PREEMPTION=n``, the RCU and
 RCU-sched APIs have identical implementations, while kernels built with
@@ -2490,8 +2490,8 @@ and local_irq_restore(), and so on.
 Sleepable RCU
 ~~~~~~~~~~~~~
 
-For well over a decade, someone saying “I need to block within an RCU
-read-side critical section” was a reliable indication that this someone
+For well over a decade, someone saying "I need to block within an RCU
+read-side critical section" was a reliable indication that this someone
 did not understand RCU. After all, if you are always blocking in an RCU
 read-side critical section, you can probably afford to use a
 higher-overhead synchronization mechanism. However, that changed with
@@ -2507,7 +2507,7 @@ this structure must be passed in to each SRCU function, for example,
 structure. The key benefit of these domains is that a slow SRCU reader
 in one domain does not delay an SRCU grace period in some other domain.
 That said, one consequence of these domains is that read-side code must
-pass a “cookie” from srcu_read_lock() to srcu_read_unlock(), for
+pass a "cookie" from srcu_read_lock() to srcu_read_unlock(), for
 example, as follows:
 
    ::
@@ -2536,9 +2536,9 @@ period to elapse. For example, this results in a self-deadlock:
        5 synchronize_srcu(&ss);
        6 srcu_read_unlock(&ss, idx);
 
-However, if line 5 acquired a mutex that was held across a
+However, if line 5 acquired a mutex that was held across a
 synchronize_srcu() for domain ``ss``, deadlock would still be
-possible. Furthermore, if line 5 acquired a mutex that was held across a
+possible. Furthermore, if line 5 acquired a mutex that was held across a
 synchronize_srcu() for some other domain ``ss1``, and if an
 ``ss1``-domain SRCU read-side critical section acquired another mutex
 that was held across as ``ss``-domain synchronize_srcu(), deadlock
@@ -2557,7 +2557,7 @@ memory barrier.
 Also unlike other RCU flavors, synchronize_srcu() may **not** be
 invoked from CPU-hotplug notifiers, due to the fact that SRCU grace
 periods make use of timers and the possibility of timers being
-temporarily “stranded” on the outgoing CPU. This stranding of timers
+temporarily "stranded" on the outgoing CPU. This stranding of timers
 means that timers posted to the outgoing CPU will not fire until late in
 the CPU-hotplug process. The problem is that if a notifier is waiting on
 an SRCU grace period, that grace period is waiting on a timer, and that
@@ -2573,7 +2573,7 @@ period has the side effect of expediting all prior grace periods that
 have not yet completed. (But please note that this is a property of the
 current implementation, not necessarily of future implementations.) In
 addition, if SRCU has been idle for longer than the interval specified
-by the ``srcutree.exp_holdoff`` kernel boot parameter (25 microseconds
+by the ``srcutree.exp_holdoff`` kernel boot parameter (25 microseconds
 by default), and if a synchronize_srcu() invocation ends this idle
 period, that invocation will be automatically expedited.
 
@@ -2619,7 +2619,7 @@ from the cache, an SRCU grace period will be very likely to have elapsed.
 Tasks RCU
 ~~~~~~~~~
 
-Some forms of tracing use “trampolines” to handle the binary rewriting
+Some forms of tracing use "trampolines" to handle the binary rewriting
 required to install different types of probes. It would be good to be
 able to free old trampolines, which sounds like a job for some form of
 RCU. However, because it is necessary to be able to install a trace
@@ -2687,7 +2687,7 @@ your architecture should also benefit from the
 number of CPUs in a socket, NUMA node, or whatever. If the number of
 CPUs is too large, use a fraction of the number of CPUs. If the number
 of CPUs is a large prime number, well, that certainly is an
-“interesting” architectural choice! More flexible arrangements might be
+"interesting" architectural choice! More flexible arrangements might be
 considered, but only if ``rcutree.rcu_fanout_leaf`` has proven
 inadequate, and only if the inadequacy has been demonstrated by a
 carefully run and realistic system-level workload.
-- 
2.30.2

Re: [PATCH 53/53] docs: RCU: avoid using UTF-8 chars

[Paul E. McKenney]

On Mon, May 10, 2021 at 12:27:05PM +0200, Mauro Carvalho Chehab wrote:
> While UTF-8 characters can be used at the Linux documentation,
> the best is to use them only when ASCII doesn't offer a good replacement.
> So, replace the occurences of the following UTF-8 characters:
> 
> 	- U+00a0 (' '): NO-BREAK SPACE
> 	- U+2013 ('–'): EN DASH
> 	- U+2014 ('—'): EM DASH
> 	- U+201c ('“'): LEFT DOUBLE QUOTATION MARK
> 	- U+201d ('”'): RIGHT DOUBLE QUOTATION MARK
> 
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Acked-by: Paul E. McKenney <paulmck@kernel.org>

> ---
>  .../Data-Structures/Data-Structures.rst       |  52 ++++----
>  .../Expedited-Grace-Periods.rst               |  40 +++---
>  .../Tree-RCU-Memory-Ordering.rst              |  10 +-
>  .../RCU/Design/Requirements/Requirements.rst  | 126 +++++++++---------
>  4 files changed, 114 insertions(+), 114 deletions(-)
> 
> diff --git a/Documentation/RCU/Design/Data-Structures/Data-Structures.rst b/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
> index f4efd6897b09..e95c6c8eeb6a 100644
> --- a/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
> +++ b/Documentation/RCU/Design/Data-Structures/Data-Structures.rst
> @@ -301,7 +301,7 @@ The ``->gp_max`` field tracks the duration of the longest grace period
>  in jiffies. It is protected by the root ``rcu_node``'s ``->lock``.
>  
>  The ``->name`` and ``->abbr`` fields distinguish between preemptible RCU
> -(“rcu_preempt” and “p”) and non-preemptible RCU (“rcu_sched” and “s”).
> +("rcu_preempt" and "p") and non-preemptible RCU ("rcu_sched" and "s").
>  These fields are used for diagnostic and tracing purposes.
>  
>  The ``rcu_node`` Structure
> @@ -456,21 +456,21 @@ expedited grace periods, respectively.
>  | Lockless grace-period computation! Such a tantalizing possibility!    |
>  | But consider the following sequence of events:                        |
>  |                                                                       |
> -| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
> +| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
>  |    wakes up, it notices that the current RCU grace period needs it to |
>  |    report in, so it sets a flag where the scheduling clock interrupt  |
>  |    will find it.                                                      |
> -| #. Meanwhile, CPU 1 is running ``force_quiescent_state()``, and       |
> -|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |
> +| #. Meanwhile, CPU 1 is running ``force_quiescent_state()``, and       |
> +|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |
>  |    as an extended quiescent state.                                    |
> -| #. CPU 0's scheduling clock interrupt fires in the middle of an RCU   |
> +| #. CPU 0's scheduling clock interrupt fires in the middle of an RCU   |
>  |    read-side critical section, and notices that the RCU core needs    |
>  |    something, so commences RCU softirq processing.                    |
> -| #. CPU 0's softirq handler executes and is just about ready to report |
> +| #. CPU 0's softirq handler executes and is just about ready to report |
>  |    its quiescent state up the ``rcu_node`` tree.                      |
> -| #. But CPU 1 beats it to the punch, completing the current grace      |
> +| #. But CPU 1 beats it to the punch, completing the current grace      |
>  |    period and starting a new one.                                     |
> -| #. CPU 0 now reports its quiescent state for the wrong grace period.  |
> +| #. CPU 0 now reports its quiescent state for the wrong grace period.  |
>  |    That grace period might now end before the RCU read-side critical  |
>  |    section. If that happens, disaster will ensue.                     |
>  |                                                                       |
> @@ -515,18 +515,18 @@ removes itself from the ``->blkd_tasks`` list, then that task must
>  advance the pointer to the next task on the list, or set the pointer to
>  ``NULL`` if there are no subsequent tasks on the list.
>  
> -For example, suppose that tasks T1, T2, and T3 are all hard-affinitied
> -to the largest-numbered CPU in the system. Then if task T1 blocked in an
> +For example, suppose that tasks T1, T2, and T3 are all hard-affinitied
> +to the largest-numbered CPU in the system. Then if task T1 blocked in an
>  RCU read-side critical section, then an expedited grace period started,
> -then task T2 blocked in an RCU read-side critical section, then a normal
> -grace period started, and finally task 3 blocked in an RCU read-side
> +then task T2 blocked in an RCU read-side critical section, then a normal
> +grace period started, and finally task 3 blocked in an RCU read-side
>  critical section, then the state of the last leaf ``rcu_node``
>  structure's blocked-task list would be as shown below:
>  
>  .. kernel-figure:: blkd_task.svg
>  
> -Task T1 is blocking both grace periods, task T2 is blocking only the
> -normal grace period, and task T3 is blocking neither grace period. Note
> +Task T1 is blocking both grace periods, task T2 is blocking only the
> +normal grace period, and task T3 is blocking neither grace period. Note
>  that these tasks will not remove themselves from this list immediately
>  upon resuming execution. They will instead remain on the list until they
>  execute the outermost ``rcu_read_unlock()`` that ends their RCU
> @@ -611,8 +611,8 @@ expressions as follows:
>     66 #endif
>  
>  The maximum number of levels in the ``rcu_node`` structure is currently
> -limited to four, as specified by lines 21-24 and the structure of the
> -subsequent “if” statement. For 32-bit systems, this allows
> +limited to four, as specified by lines 21-24 and the structure of the
> +subsequent "if" statement. For 32-bit systems, this allows
>  16*32*32*32=524,288 CPUs, which should be sufficient for the next few
>  years at least. For 64-bit systems, 16*64*64*64=4,194,304 CPUs is
>  allowed, which should see us through the next decade or so. This
> @@ -638,9 +638,9 @@ fields. The number of CPUs per leaf ``rcu_node`` structure is therefore
>  limited to 16 given the default value of ``CONFIG_RCU_FANOUT_LEAF``. If
>  ``CONFIG_RCU_FANOUT_LEAF`` is unspecified, the value selected is based
>  on the word size of the system, just as for ``CONFIG_RCU_FANOUT``.
> -Lines 11-19 perform this computation.
> +Lines 11-19 perform this computation.
>  
> -Lines 21-24 compute the maximum number of CPUs supported by a
> +Lines 21-24 compute the maximum number of CPUs supported by a
>  single-level (which contains a single ``rcu_node`` structure),
>  two-level, three-level, and four-level ``rcu_node`` tree, respectively,
>  given the fanout specified by ``RCU_FANOUT`` and ``RCU_FANOUT_LEAF``.
> @@ -649,18 +649,18 @@ These numbers of CPUs are retained in the ``RCU_FANOUT_1``,
>  variables, respectively.
>  
>  These variables are used to control the C-preprocessor ``#if`` statement
> -spanning lines 26-66 that computes the number of ``rcu_node`` structures
> +spanning lines 26-66 that computes the number of ``rcu_node`` structures
>  required for each level of the tree, as well as the number of levels
>  required. The number of levels is placed in the ``NUM_RCU_LVLS``
> -C-preprocessor variable by lines 27, 35, 44, and 54. The number of
> +C-preprocessor variable by lines 27, 35, 44, and 54. The number of
>  ``rcu_node`` structures for the topmost level of the tree is always
>  exactly one, and this value is unconditionally placed into
> -``NUM_RCU_LVL_0`` by lines 28, 36, 45, and 55. The rest of the levels
> +``NUM_RCU_LVL_0`` by lines 28, 36, 45, and 55. The rest of the levels
>  (if any) of the ``rcu_node`` tree are computed by dividing the maximum
>  number of CPUs by the fanout supported by the number of levels from the
>  current level down, rounding up. This computation is performed by
> -lines 37, 46-47, and 56-58. Lines 31-33, 40-42, 50-52, and 62-63 create
> -initializers for lockdep lock-class names. Finally, lines 64-66 produce
> +lines 37, 46-47, and 56-58. Lines 31-33, 40-42, 50-52, and 62-63 create
> +initializers for lockdep lock-class names. Finally, lines 64-66 produce
>  an error if the maximum number of CPUs is too large for the specified
>  fanout.
>  
> @@ -716,13 +716,13 @@ In this figure, the ``->head`` pointer references the first RCU callback
>  in the list. The ``->tails[RCU_DONE_TAIL]`` array element references the
>  ``->head`` pointer itself, indicating that none of the callbacks is
>  ready to invoke. The ``->tails[RCU_WAIT_TAIL]`` array element references
> -callback CB 2's ``->next`` pointer, which indicates that CB 1 and CB 2
> +callback CB 2's ``->next`` pointer, which indicates that CB 1 and CB 2
>  are both waiting on the current grace period, give or take possible
>  disagreements about exactly which grace period is the current one. The
>  ``->tails[RCU_NEXT_READY_TAIL]`` array element references the same RCU
>  callback that ``->tails[RCU_WAIT_TAIL]`` does, which indicates that
>  there are no callbacks waiting on the next RCU grace period. The
> -``->tails[RCU_NEXT_TAIL]`` array element references CB 4's ``->next``
> +``->tails[RCU_NEXT_TAIL]`` array element references CB 4's ``->next``
>  pointer, indicating that all the remaining RCU callbacks have not yet
>  been assigned to an RCU grace period. Note that the
>  ``->tails[RCU_NEXT_TAIL]`` array element always references the last RCU
> @@ -1031,7 +1031,7 @@ field to record the offset of the ``rcu_head`` structure within the
>  enclosing RCU-protected data structure.
>  
>  Both of these fields are used internally by RCU. From the viewpoint of
> -RCU users, this structure is an opaque “cookie”.
> +RCU users, this structure is an opaque "cookie".
>  
>  +-----------------------------------------------------------------------+
>  | **Quick Quiz**:                                                       |
> diff --git a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
> index 6f89cf1e567d..742921a7532b 100644
> --- a/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
> +++ b/Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst
> @@ -304,8 +304,8 @@ representing the elements of the ``->exp_wq[]`` array.
>  
>  .. kernel-figure:: Funnel0.svg
>  
> -The next diagram shows the situation after the arrival of Task A and
> -Task B at the leftmost and rightmost leaf ``rcu_node`` structures,
> +The next diagram shows the situation after the arrival of Task A and
> +Task B at the leftmost and rightmost leaf ``rcu_node`` structures,
>  respectively. The current value of the ``rcu_state`` structure's
>  ``->expedited_sequence`` field is zero, so adding three and clearing the
>  bottom bit results in the value two, which both tasks record in the
> @@ -313,13 +313,13 @@ bottom bit results in the value two, which both tasks record in the
>  
>  .. kernel-figure:: Funnel1.svg
>  
> -Each of Tasks A and B will move up to the root ``rcu_node`` structure.
> -Suppose that Task A wins, recording its desired grace-period sequence
> +Each of Tasks A and B will move up to the root ``rcu_node`` structure.
> +Suppose that Task A wins, recording its desired grace-period sequence
>  number and resulting in the state shown below:
>  
>  .. kernel-figure:: Funnel2.svg
>  
> -Task A now advances to initiate a new grace period, while Task B moves
> +Task A now advances to initiate a new grace period, while Task B moves
>  up to the root ``rcu_node`` structure, and, seeing that its desired
>  sequence number is already recorded, blocks on ``->exp_wq[1]``.
>  
> @@ -340,7 +340,7 @@ sequence number is already recorded, blocks on ``->exp_wq[1]``.
>  | ``->exp_wq[1]``.                                                      |
>  +-----------------------------------------------------------------------+
>  
> -If Tasks C and D also arrive at this point, they will compute the same
> +If Tasks C and D also arrive at this point, they will compute the same
>  desired grace-period sequence number, and see that both leaf
>  ``rcu_node`` structures already have that value recorded. They will
>  therefore block on their respective ``rcu_node`` structures'
> @@ -348,52 +348,52 @@ therefore block on their respective ``rcu_node`` structures'
>  
>  .. kernel-figure:: Funnel3.svg
>  
> -Task A now acquires the ``rcu_state`` structure's ``->exp_mutex`` and
> +Task A now acquires the ``rcu_state`` structure's ``->exp_mutex`` and
>  initiates the grace period, which increments ``->expedited_sequence``.
> -Therefore, if Tasks E and F arrive, they will compute a desired sequence
> +Therefore, if Tasks E and F arrive, they will compute a desired sequence
>  number of 4 and will record this value as shown below:
>  
>  .. kernel-figure:: Funnel4.svg
>  
> -Tasks E and F will propagate up the ``rcu_node`` combining tree, with
> -Task F blocking on the root ``rcu_node`` structure and Task E wait for
> -Task A to finish so that it can start the next grace period. The
> +Tasks E and F will propagate up the ``rcu_node`` combining tree, with
> +Task F blocking on the root ``rcu_node`` structure and Task E wait for
> +Task A to finish so that it can start the next grace period. The
>  resulting state is as shown below:
>  
>  .. kernel-figure:: Funnel5.svg
>  
> -Once the grace period completes, Task A starts waking up the tasks
> +Once the grace period completes, Task A starts waking up the tasks
>  waiting for this grace period to complete, increments the
>  ``->expedited_sequence``, acquires the ``->exp_wake_mutex`` and then
>  releases the ``->exp_mutex``. This results in the following state:
>  
>  .. kernel-figure:: Funnel6.svg
>  
> -Task E can then acquire ``->exp_mutex`` and increment
> -``->expedited_sequence`` to the value three. If new tasks G and H arrive
> +Task E can then acquire ``->exp_mutex`` and increment
> +``->expedited_sequence`` to the value three. If new tasks G and H arrive
>  and moves up the combining tree at the same time, the state will be as
>  follows:
>  
>  .. kernel-figure:: Funnel7.svg
>  
>  Note that three of the root ``rcu_node`` structure's waitqueues are now
> -occupied. However, at some point, Task A will wake up the tasks blocked
> +occupied. However, at some point, Task A will wake up the tasks blocked
>  on the ``->exp_wq`` waitqueues, resulting in the following state:
>  
>  .. kernel-figure:: Funnel8.svg
>  
> -Execution will continue with Tasks E and H completing their grace
> +Execution will continue with Tasks E and H completing their grace
>  periods and carrying out their wakeups.
>  
>  +-----------------------------------------------------------------------+
>  | **Quick Quiz**:                                                       |
>  +-----------------------------------------------------------------------+
> -| What happens if Task A takes so long to do its wakeups that Task E's  |
> +| What happens if Task A takes so long to do its wakeups that Task E's  |
>  | grace period completes?                                               |
>  +-----------------------------------------------------------------------+
>  | **Answer**:                                                           |
>  +-----------------------------------------------------------------------+
> -| Then Task E will block on the ``->exp_wake_mutex``, which will also   |
> +| Then Task E will block on the ``->exp_wake_mutex``, which will also   |
>  | prevent it from releasing ``->exp_mutex``, which in turn will prevent |
>  | the next grace period from starting. This last is important in        |
>  | preventing overflow of the ``->exp_wq[]`` array.                      |
> @@ -464,8 +464,8 @@ code need not worry about POSIX signals. Unfortunately, it has the
>  corresponding disadvantage that workqueues cannot be used until they are
>  initialized, which does not happen until some time after the scheduler
>  spawns the first task. Given that there are parts of the kernel that
> -really do want to execute grace periods during this mid-boot “dead
> -zone”, expedited grace periods must do something else during thie time.
> +really do want to execute grace periods during this mid-boot "dead
> +zone", expedited grace periods must do something else during thie time.
>  
>  What they do is to fall back to the old practice of requiring that the
>  requesting task drive the expedited grace period, as was the case before
> diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
> index a648b423ba0e..d76c6bfdc659 100644
> --- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
> +++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
> @@ -215,7 +215,7 @@ newly arrived RCU callbacks against future grace periods:
>     43 }
>  
>  But the only part of ``rcu_prepare_for_idle()`` that really matters for
> -this discussion are lines 37–39. We will therefore abbreviate this
> +this discussion are lines 37-39. We will therefore abbreviate this
>  function as follows:
>  
>  .. kernel-figure:: rcu_node-lock.svg
> @@ -418,7 +418,7 @@ wait on.
>  | It is indeed not necessary for the grace period to wait on such a     |
>  | critical section. However, it is permissible to wait on it. And it is |
>  | furthermore important to wait on it, as this lazy approach is far     |
> -| more scalable than a “big bang” all-at-once grace-period start could  |
> +| more scalable than a "big bang" all-at-once grace-period start could  |
>  | possibly be.                                                          |
>  +-----------------------------------------------------------------------+
>  
> @@ -448,7 +448,7 @@ proceeds upwards from that point, and the ``rcu_node`` ``->lock``
>  guarantees that the first CPU's quiescent state happens before the
>  remainder of the second CPU's traversal. Applying this line of thought
>  repeatedly shows that all CPUs' quiescent states happen before the last
> -CPU traverses through the root ``rcu_node`` structure, the “last CPU”
> +CPU traverses through the root ``rcu_node`` structure, the "last CPU"
>  being the one that clears the last bit in the root ``rcu_node``
>  structure's ``->qsmask`` field.
>  
> @@ -501,8 +501,8 @@ Forcing Quiescent States
>  
>  As noted above, idle and offline CPUs cannot report their own quiescent
>  states, and therefore the grace-period kernel thread must do the
> -reporting on their behalf. This process is called “forcing quiescent
> -states”, it is repeated every few jiffies, and its ordering effects are
> +reporting on their behalf. This process is called "forcing quiescent
> +states", it is repeated every few jiffies, and its ordering effects are
>  shown below:
>  
>  .. kernel-figure:: TreeRCU-gp-fqs.svg
> diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
> index 38a39476fc24..a3493b34f3dd 100644
> --- a/Documentation/RCU/Design/Requirements/Requirements.rst
> +++ b/Documentation/RCU/Design/Requirements/Requirements.rst
> @@ -4,7 +4,7 @@ A Tour Through RCU's Requirements
>  
>  Copyright IBM Corporation, 2015
>  
> -Author: Paul E. McKenney
> +Author: Paul E. McKenney
>  
>  The initial version of this document appeared in the
>  `LWN <https://lwn.net/>`_ on those articles:
> @@ -66,7 +66,7 @@ Grace-Period Guarantee
>  
>  RCU's grace-period guarantee is unusual in being premeditated: Jack
>  Slingwine and I had this guarantee firmly in mind when we started work
> -on RCU (then called “rclock”) in the early 1990s. That said, the past
> +on RCU (then called "rclock") in the early 1990s. That said, the past
>  two decades of experience with RCU have produced a much more detailed
>  understanding of this guarantee.
>  
> @@ -102,7 +102,7 @@ overhead to readers, for example:
>        15   WRITE_ONCE(y, 1);
>        16 }
>  
> -Because the synchronize_rcu() on line 14 waits for all pre-existing
> +Because the synchronize_rcu() on line 14 waits for all pre-existing
>  readers, any instance of thread0() that loads a value of zero from
>  ``x`` must complete before thread1() stores to ``y``, so that
>  instance must also load a value of zero from ``y``. Similarly, any
> @@ -178,7 +178,7 @@ little or no synchronization overhead in do_something_dlm().
>  +-----------------------------------------------------------------------+
>  | **Quick Quiz**:                                                       |
>  +-----------------------------------------------------------------------+
> -| Why is the synchronize_rcu() on line 28 needed?                       |
> +| Why is the synchronize_rcu() on line 28 needed?                       |
>  +-----------------------------------------------------------------------+
>  | **Answer**:                                                           |
>  +-----------------------------------------------------------------------+
> @@ -244,7 +244,7 @@ their rights to reorder this code as follows:
>        16 }
>  
>  If an RCU reader fetches ``gp`` just after ``add_gp_buggy_optimized``
> -executes line 11, it will see garbage in the ``->a`` and ``->b`` fields.
> +executes line 11, it will see garbage in the ``->a`` and ``->b`` fields.
>  And this is but one of many ways in which compiler and hardware
>  optimizations could cause trouble. Therefore, we clearly need some way
>  to prevent the compiler and the CPU from reordering in this manner,
> @@ -279,11 +279,11 @@ shows an example of insertion:
>        15   return true;
>        16 }
>  
> -The rcu_assign_pointer() on line 13 is conceptually equivalent to a
> +The rcu_assign_pointer() on line 13 is conceptually equivalent to a
>  simple assignment statement, but also guarantees that its assignment
> -will happen after the two assignments in lines 11 and 12, similar to the
> +will happen after the two assignments in lines 11 and 12, similar to the
>  C11 ``memory_order_release`` store operation. It also prevents any
> -number of “interesting” compiler optimizations, for example, the use of
> +number of "interesting" compiler optimizations, for example, the use of
>  ``gp`` as a scratch location immediately preceding the assignment.
>  
>  +-----------------------------------------------------------------------+
> @@ -410,11 +410,11 @@ This process is implemented by remove_gp_synchronous():
>        15   return true;
>        16 }
>  
> -This function is straightforward, with line 13 waiting for a grace
> -period before line 14 frees the old data element. This waiting ensures
> -that readers will reach line 7 of do_something_gp() before the data
> +This function is straightforward, with line 13 waiting for a grace
> +period before line 14 frees the old data element. This waiting ensures
> +that readers will reach line 7 of do_something_gp() before the data
>  element referenced by ``p`` is freed. The rcu_access_pointer() on
> -line 6 is similar to rcu_dereference(), except that:
> +line 6 is similar to rcu_dereference(), except that:
>  
>  #. The value returned by rcu_access_pointer() cannot be
>     dereferenced. If you want to access the value pointed to as well as
> @@ -488,25 +488,25 @@ systems with more than one CPU:
>     section ends and the time that synchronize_rcu() returns. Without
>     this guarantee, a pre-existing RCU read-side critical section might
>     hold a reference to the newly removed ``struct foo`` after the
> -   kfree() on line 14 of remove_gp_synchronous().
> +   kfree() on line 14 of remove_gp_synchronous().
>  #. Each CPU that has an RCU read-side critical section that ends after
>     synchronize_rcu() returns is guaranteed to execute a full memory
>     barrier between the time that synchronize_rcu() begins and the
>     time that the RCU read-side critical section begins. Without this
>     guarantee, a later RCU read-side critical section running after the
> -   kfree() on line 14 of remove_gp_synchronous() might later run
> +   kfree() on line 14 of remove_gp_synchronous() might later run
>     do_something_gp() and find the newly deleted ``struct foo``.
>  #. If the task invoking synchronize_rcu() remains on a given CPU,
>     then that CPU is guaranteed to execute a full memory barrier sometime
>     during the execution of synchronize_rcu(). This guarantee ensures
> -   that the kfree() on line 14 of remove_gp_synchronous() really
> -   does execute after the removal on line 11.
> +   that the kfree() on line 14 of remove_gp_synchronous() really
> +   does execute after the removal on line 11.
>  #. If the task invoking synchronize_rcu() migrates among a group of
>     CPUs during that invocation, then each of the CPUs in that group is
>     guaranteed to execute a full memory barrier sometime during the
>     execution of synchronize_rcu(). This guarantee also ensures that
> -   the kfree() on line 14 of remove_gp_synchronous() really does
> -   execute after the removal on line 11, but also in the case where the
> +   the kfree() on line 14 of remove_gp_synchronous() really does
> +   execute after the removal on line 11, but also in the case where the
>     thread executing the synchronize_rcu() migrates in the meantime.
>  
>  +-----------------------------------------------------------------------+
> @@ -525,8 +525,8 @@ systems with more than one CPU:
>  | In other words, a given instance of synchronize_rcu() can avoid       |
>  | waiting on a given RCU read-side critical section only if it can      |
>  | prove that synchronize_rcu() started first.                           |
> -| A related question is “When rcu_read_lock() doesn't generate any      |
> -| code, why does it matter how it relates to a grace period?” The       |
> +| A related question is "When rcu_read_lock() doesn't generate any      |
> +| code, why does it matter how it relates to a grace period?" The       |
>  | answer is that it is not the relationship of rcu_read_lock()          |
>  | itself that is important, but rather the relationship of the code     |
>  | within the enclosed RCU read-side critical section to the code        |
> @@ -538,7 +538,7 @@ systems with more than one CPU:
>  | of any access following the grace period.                             |
>  |                                                                       |
>  | As of late 2016, mathematical models of RCU take this viewpoint, for  |
> -| example, see slides 62 and 63 of the `2016 LinuxCon                   |
> +| example, see slides 62 and 63 of the `2016 LinuxCon                   |
>  | EU <http://www2.rdrop.com/users/paulmck/scalability/paper/LinuxMM.201 |
>  | 6.10.04c.LCE.pdf>`__                                                  |
>  | presentation.                                                         |
> @@ -584,9 +584,9 @@ systems with more than one CPU:
>  |                                                                       |
>  | And similarly, without a memory barrier between the beginning of the  |
>  | grace period and the beginning of the RCU read-side critical section, |
> -| CPU 1 might end up accessing the freelist.                            |
> +| CPU 1 might end up accessing the freelist.                            |
>  |                                                                       |
> -| The “as if” rule of course applies, so that any implementation that   |
> +| The "as if" rule of course applies, so that any implementation that   |
>  | acts as if the appropriate memory barriers were in place is a correct |
>  | implementation. That said, it is much easier to fool yourself into    |
>  | believing that you have adhered to the as-if rule than it is to       |
> @@ -1002,7 +1002,7 @@ RCU implementation must abide by them. They therefore bear repeating:
>     ECC errors, NMIs, and other hardware events. Although a delay of more
>     than about 20 seconds can result in splats, the RCU implementation is
>     obligated to use algorithms that can tolerate extremely long delays,
> -   but where “extremely long” is not long enough to allow wrap-around
> +   but where "extremely long" is not long enough to allow wrap-around
>     when incrementing a 64-bit counter.
>  #. Both the compiler and the CPU can reorder memory accesses. Where it
>     matters, RCU must use compiler directives and memory-barrier
> @@ -1169,7 +1169,7 @@ Energy efficiency is a critical component of performance today, and
>  Linux-kernel RCU implementations must therefore avoid unnecessarily
>  awakening idle CPUs. I cannot claim that this requirement was
>  premeditated. In fact, I learned of it during a telephone conversation
> -in which I was given “frank and open” feedback on the importance of
> +in which I was given "frank and open" feedback on the importance of
>  energy efficiency in battery-powered systems and on specific
>  energy-efficiency shortcomings of the Linux-kernel RCU implementation.
>  In my experience, the battery-powered embedded community will consider
> @@ -1234,7 +1234,7 @@ requirements: A storm of synchronize_rcu_expedited() invocations on
>  4096 CPUs should at least make reasonable forward progress. In return
>  for its shorter latencies, synchronize_rcu_expedited() is permitted
>  to impose modest degradation of real-time latency on non-idle online
> -CPUs. Here, “modest” means roughly the same latency degradation as a
> +CPUs. Here, "modest" means roughly the same latency degradation as a
>  scheduling-clock interrupt.
>  
>  There are a number of situations where even
> @@ -1274,8 +1274,8 @@ be used in place of synchronize_rcu() as follows:
>        28 }
>  
>  A definition of ``struct foo`` is finally needed, and appears on
> -lines 1-5. The function remove_gp_cb() is passed to call_rcu()
> -on line 25, and will be invoked after the end of a subsequent grace
> +lines 1-5. The function remove_gp_cb() is passed to call_rcu()
> +on line 25, and will be invoked after the end of a subsequent grace
>  period. This gets the same effect as remove_gp_synchronous(), but
>  without forcing the updater to wait for a grace period to elapse. The
>  call_rcu() function may be used in a number of situations where
> @@ -1294,23 +1294,23 @@ threads or (in the Linux kernel) workqueues.
>  +-----------------------------------------------------------------------+
>  | **Quick Quiz**:                                                       |
>  +-----------------------------------------------------------------------+
> -| Why does line 19 use rcu_access_pointer()? After all,                 |
> -| call_rcu() on line 25 stores into the structure, which would          |
> +| Why does line 19 use rcu_access_pointer()? After all,                 |
> +| call_rcu() on line 25 stores into the structure, which would          |
>  | interact badly with concurrent insertions. Doesn't this mean that     |
>  | rcu_dereference() is required?                                        |
>  +-----------------------------------------------------------------------+
>  | **Answer**:                                                           |
>  +-----------------------------------------------------------------------+
> -| Presumably the ``->gp_lock`` acquired on line 18 excludes any         |
> +| Presumably the ``->gp_lock`` acquired on line 18 excludes any         |
>  | changes, including any insertions that rcu_dereference() would        |
>  | protect against. Therefore, any insertions will be delayed until      |
> -| after ``->gp_lock`` is released on line 25, which in turn means that  |
> +| after ``->gp_lock`` is released on line 25, which in turn means that  |
>  | rcu_access_pointer() suffices.                                        |
>  +-----------------------------------------------------------------------+
>  
>  However, all that remove_gp_cb() is doing is invoking kfree() on
>  the data element. This is a common idiom, and is supported by
> -kfree_rcu(), which allows “fire and forget” operation as shown
> +kfree_rcu(), which allows "fire and forget" operation as shown
>  below:
>  
>     ::
> @@ -1396,8 +1396,8 @@ may be used for this purpose, as shown below:
>        18   return true;
>        19 }
>  
> -On line 14, get_state_synchronize_rcu() obtains a “cookie” from RCU,
> -then line 15 carries out other tasks, and finally, line 16 returns
> +On line 14, get_state_synchronize_rcu() obtains a "cookie" from RCU,
> +then line 15 carries out other tasks, and finally, line 16 returns
>  immediately if a grace period has elapsed in the meantime, but otherwise
>  waits as required. The need for ``get_state_synchronize_rcu`` and
>  cond_synchronize_rcu() has appeared quite recently, so it is too
> @@ -1420,9 +1420,9 @@ example, an infinite loop in an RCU read-side critical section must by
>  definition prevent later grace periods from ever completing. For a more
>  involved example, consider a 64-CPU system built with
>  ``CONFIG_RCU_NOCB_CPU=y`` and booted with ``rcu_nocbs=1-63``, where
> -CPUs 1 through 63 spin in tight loops that invoke call_rcu(). Even
> +CPUs 1 through 63 spin in tight loops that invoke call_rcu(). Even
>  if these tight loops also contain calls to cond_resched() (thus
> -allowing grace periods to complete), CPU 0 simply will not be able to
> +allowing grace periods to complete), CPU 0 simply will not be able to
>  invoke callbacks as fast as the other 63 CPUs can register them, at
>  least not until the system runs out of memory. In both of these
>  examples, the Spiderman principle applies: With great power comes great
> @@ -1433,7 +1433,7 @@ callbacks.
>  RCU takes the following steps to encourage timely completion of grace
>  periods:
>  
> -#. If a grace period fails to complete within 100 milliseconds, RCU
> +#. If a grace period fails to complete within 100 milliseconds, RCU
>     causes future invocations of cond_resched() on the holdout CPUs
>     to provide an RCU quiescent state. RCU also causes those CPUs'
>     need_resched() invocations to return ``true``, but only after the
> @@ -1442,12 +1442,12 @@ periods:
>     indefinitely in the kernel without scheduling-clock interrupts, which
>     defeats the above need_resched() strategem. RCU will therefore
>     invoke resched_cpu() on any ``nohz_full`` CPUs still holding out
> -   after 109 milliseconds.
> +   after 109 milliseconds.
>  #. In kernels built with ``CONFIG_RCU_BOOST=y``, if a given task that
>     has been preempted within an RCU read-side critical section is
> -   holding out for more than 500 milliseconds, RCU will resort to
> +   holding out for more than 500 milliseconds, RCU will resort to
>     priority boosting.
> -#. If a CPU is still holding out 10 seconds into the grace period, RCU
> +#. If a CPU is still holding out 10 seconds into the grace period, RCU
>     will invoke resched_cpu() on it regardless of its ``nohz_full``
>     state.
>  
> @@ -1579,7 +1579,7 @@ period.
>  Software-Engineering Requirements
>  ---------------------------------
>  
> -Between Murphy's Law and “To err is human”, it is necessary to guard
> +Between Murphy's Law and "To err is human", it is necessary to guard
>  against mishaps and misuse:
>  
>  #. It is all too easy to forget to use rcu_read_lock() everywhere
> @@ -1626,7 +1626,7 @@ against mishaps and misuse:
>     `patch <https://lore.kernel.org/r/20100319013024.GA28456@Krystal>`__.
>  #. An infinite loop in an RCU read-side critical section will eventually
>     trigger an RCU CPU stall warning splat, with the duration of
> -   “eventually” being controlled by the ``RCU_CPU_STALL_TIMEOUT``
> +   "eventually" being controlled by the ``RCU_CPU_STALL_TIMEOUT``
>     ``Kconfig`` option, or, alternatively, by the
>     ``rcupdate.rcu_cpu_stall_timeout`` boot/sysfs parameter. However, RCU
>     is not obligated to produce this splat unless there is a grace period
> @@ -1704,7 +1704,7 @@ Configuration
>  
>  RCU's goal is automatic configuration, so that almost nobody needs to
>  worry about RCU's ``Kconfig`` options. And for almost all users, RCU
> -does in fact work well “out of the box.”
> +does in fact work well "out of the box."
>  
>  However, there are specialized use cases that are handled by kernel boot
>  parameters and ``Kconfig`` options. Unfortunately, the ``Kconfig``
> @@ -1733,7 +1733,7 @@ listings.
>  
>  RCU must therefore wait for a given CPU to actually come online before
>  it can allow itself to believe that the CPU actually exists. The
> -resulting “ghost CPUs” (which are never going to come online) cause a
> +resulting "ghost CPUs" (which are never going to come online) cause a
>  number of `interesting
>  complications <https://paulmck.livejournal.com/37494.html>`__.
>  
> @@ -1789,7 +1789,7 @@ normally.
>  | **Answer**:                                                           |
>  +-----------------------------------------------------------------------+
>  | Very carefully!                                                       |
> -| During the “dead zone” between the time that the scheduler spawns the |
> +| During the "dead zone" between the time that the scheduler spawns the |
>  | first task and the time that all of RCU's kthreads have been spawned, |
>  | all synchronous grace periods are handled by the expedited            |
>  | grace-period mechanism. At runtime, this expedited mechanism relies   |
> @@ -1824,7 +1824,7 @@ Some Linux-kernel architectures can enter an interrupt handler from
>  non-idle process context, and then just never leave it, instead
>  stealthily transitioning back to process context. This trick is
>  sometimes used to invoke system calls from inside the kernel. These
> -“half-interrupts” mean that RCU has to be very careful about how it
> +"half-interrupts" mean that RCU has to be very careful about how it
>  counts interrupt nesting levels. I learned of this requirement the hard
>  way during a rewrite of RCU's dyntick-idle code.
>  
> @@ -1921,7 +1921,7 @@ and go. It is of course illegal to use any RCU API member from an
>  offline CPU, with the exception of `SRCU <Sleepable RCU_>`__ read-side
>  critical sections. This requirement was present from day one in
>  DYNIX/ptx, but on the other hand, the Linux kernel's CPU-hotplug
> -implementation is “interesting.”
> +implementation is "interesting."
>  
>  The Linux-kernel CPU-hotplug implementation has notifiers that are used
>  to allow the various kernel subsystems (including RCU) to respond
> @@ -2268,7 +2268,7 @@ remain zero during all phases of grace-period processing, and that bit
>  happens to map to the bottom bit of the ``rcu_head`` structure's
>  ``->next`` field. RCU makes this guarantee as long as call_rcu() is
>  used to post the callback, as opposed to kfree_rcu() or some future
> -“lazy” variant of call_rcu() that might one day be created for
> +"lazy" variant of call_rcu() that might one day be created for
>  energy-efficiency purposes.
>  
>  That said, there are limits. RCU requires that the ``rcu_head``
> @@ -2281,7 +2281,7 @@ architecture provides only two-byte alignment, and thus acts as
>  alignment's least common denominator.
>  
>  The reason for reserving the bottom bit of pointers to ``rcu_head``
> -structures is to leave the door open to “lazy” callbacks whose
> +structures is to leave the door open to "lazy" callbacks whose
>  invocations can safely be deferred. Deferring invocation could
>  potentially have energy-efficiency benefits, but only if the rate of
>  non-lazy callbacks decreases significantly for some important workload.
> @@ -2354,8 +2354,8 @@ which in practice also means that RCU must have an aggressive
>  stress-test suite. This stress-test suite is called ``rcutorture``.
>  
>  Although the need for ``rcutorture`` was no surprise, the current
> -immense popularity of the Linux kernel is posing interesting—and perhaps
> -unprecedented—validation challenges. To see this, keep in mind that
> +immense popularity of the Linux kernel is posing interesting-and perhaps
> +unprecedented-validation challenges. To see this, keep in mind that
>  there are well over one billion instances of the Linux kernel running
>  today, given Android smartphones, Linux-powered televisions, and
>  servers. This number can be expected to increase sharply with the advent
> @@ -2399,7 +2399,7 @@ single flavor. The read-side API remains, and continues to disable
>  softirq and to be accounted for by lockdep. Much of the material in this
>  section is therefore strictly historical in nature.
>  
> -The softirq-disable (AKA “bottom-half”, hence the “_bh” abbreviations)
> +The softirq-disable (AKA "bottom-half", hence the "_bh" abbreviations)
>  flavor of RCU, or *RCU-bh*, was developed by Dipankar Sarma to provide a
>  flavor of RCU that could withstand the network-based denial-of-service
>  attacks researched by Robert Olsson. These attacks placed so much
> @@ -2458,7 +2458,7 @@ effect of also waiting for all pre-existing interrupt and NMI handlers.
>  However, there are legitimate preemptible-RCU implementations that do
>  not have this property, given that any point in the code outside of an
>  RCU read-side critical section can be a quiescent state. Therefore,
> -*RCU-sched* was created, which follows “classic” RCU in that an
> +*RCU-sched* was created, which follows "classic" RCU in that an
>  RCU-sched grace period waits for pre-existing interrupt and NMI
>  handlers. In kernels built with ``CONFIG_PREEMPTION=n``, the RCU and
>  RCU-sched APIs have identical implementations, while kernels built with
> @@ -2490,8 +2490,8 @@ and local_irq_restore(), and so on.
>  Sleepable RCU
>  ~~~~~~~~~~~~~
>  
> -For well over a decade, someone saying “I need to block within an RCU
> -read-side critical section” was a reliable indication that this someone
> +For well over a decade, someone saying "I need to block within an RCU
> +read-side critical section" was a reliable indication that this someone
>  did not understand RCU. After all, if you are always blocking in an RCU
>  read-side critical section, you can probably afford to use a
>  higher-overhead synchronization mechanism. However, that changed with
> @@ -2507,7 +2507,7 @@ this structure must be passed in to each SRCU function, for example,
>  structure. The key benefit of these domains is that a slow SRCU reader
>  in one domain does not delay an SRCU grace period in some other domain.
>  That said, one consequence of these domains is that read-side code must
> -pass a “cookie” from srcu_read_lock() to srcu_read_unlock(), for
> +pass a "cookie" from srcu_read_lock() to srcu_read_unlock(), for
>  example, as follows:
>  
>     ::
> @@ -2536,9 +2536,9 @@ period to elapse. For example, this results in a self-deadlock:
>         5 synchronize_srcu(&ss);
>         6 srcu_read_unlock(&ss, idx);
>  
> -However, if line 5 acquired a mutex that was held across a
> +However, if line 5 acquired a mutex that was held across a
>  synchronize_srcu() for domain ``ss``, deadlock would still be
> -possible. Furthermore, if line 5 acquired a mutex that was held across a
> +possible. Furthermore, if line 5 acquired a mutex that was held across a
>  synchronize_srcu() for some other domain ``ss1``, and if an
>  ``ss1``-domain SRCU read-side critical section acquired another mutex
>  that was held across as ``ss``-domain synchronize_srcu(), deadlock
> @@ -2557,7 +2557,7 @@ memory barrier.
>  Also unlike other RCU flavors, synchronize_srcu() may **not** be
>  invoked from CPU-hotplug notifiers, due to the fact that SRCU grace
>  periods make use of timers and the possibility of timers being
> -temporarily “stranded” on the outgoing CPU. This stranding of timers
> +temporarily "stranded" on the outgoing CPU. This stranding of timers
>  means that timers posted to the outgoing CPU will not fire until late in
>  the CPU-hotplug process. The problem is that if a notifier is waiting on
>  an SRCU grace period, that grace period is waiting on a timer, and that
> @@ -2573,7 +2573,7 @@ period has the side effect of expediting all prior grace periods that
>  have not yet completed. (But please note that this is a property of the
>  current implementation, not necessarily of future implementations.) In
>  addition, if SRCU has been idle for longer than the interval specified
> -by the ``srcutree.exp_holdoff`` kernel boot parameter (25 microseconds
> +by the ``srcutree.exp_holdoff`` kernel boot parameter (25 microseconds
>  by default), and if a synchronize_srcu() invocation ends this idle
>  period, that invocation will be automatically expedited.
>  
> @@ -2619,7 +2619,7 @@ from the cache, an SRCU grace period will be very likely to have elapsed.
>  Tasks RCU
>  ~~~~~~~~~
>  
> -Some forms of tracing use “trampolines” to handle the binary rewriting
> +Some forms of tracing use "trampolines" to handle the binary rewriting
>  required to install different types of probes. It would be good to be
>  able to free old trampolines, which sounds like a job for some form of
>  RCU. However, because it is necessary to be able to install a trace
> @@ -2687,7 +2687,7 @@ your architecture should also benefit from the
>  number of CPUs in a socket, NUMA node, or whatever. If the number of
>  CPUs is too large, use a fraction of the number of CPUs. If the number
>  of CPUs is a large prime number, well, that certainly is an
> -“interesting” architectural choice! More flexible arrangements might be
> +"interesting" architectural choice! More flexible arrangements might be
>  considered, but only if ``rcutree.rcu_fanout_leaf`` has proven
>  inadequate, and only if the inadequacy has been demonstrated by a
>  carefully run and realistic system-level workload.
> -- 
> 2.30.2
> 

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Thorsten Leemhuis]

On 10.05.21 12:26, Mauro Carvalho Chehab wrote:
>
> As Linux developers are all around the globe, and not everybody has UTF-8
> as their default charset, better to use UTF-8 only on cases where it is really
> needed.
> […]
> The remaining patches on series address such cases on *.rst files and 
> inside the Documentation/ABI, using this perl map table in order to do the
> charset conversion:
> 
> my %char_map = (
> […]
> 	0x2013 => '-',		# EN DASH
> 	0x2014 => '-',		# EM DASH

I might be performing bike shedding here, but wouldn't it be better to
replace those two with "--", as explained in
https://en.wikipedia.org/wiki/Dash#Approximating_the_em_dash_with_two_or_three_hyphens

For EM DASH there seems to be even "---", but I'd say that is a bit too
much.

Or do you fear the extra work as some lines then might break the
80-character limit then?

Ciao, Thorsten

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 12:52:44 +0200
Thorsten Leemhuis <linux@leemhuis.info> escreveu:

> On 10.05.21 12:26, Mauro Carvalho Chehab wrote:
> >
> > As Linux developers are all around the globe, and not everybody has UTF-8
> > as their default charset, better to use UTF-8 only on cases where it is really
> > needed.
> > […]
> > The remaining patches on series address such cases on *.rst files and 
> > inside the Documentation/ABI, using this perl map table in order to do the
> > charset conversion:
> > 
> > my %char_map = (
> > […]
> > 	0x2013 => '-',		# EN DASH
> > 	0x2014 => '-',		# EM DASH  


> I might be performing bike shedding here, but wouldn't it be better to
> replace those two with "--", as explained in
> https://en.wikipedia.org/wiki/Dash#Approximating_the_em_dash_with_two_or_three_hyphens
> 
> For EM DASH there seems to be even "---", but I'd say that is a bit too
> much.

Yeah, we can do, instead:

 	0x2013 => '--',		# EN DASH
 	0x2014 => '---',	# EM DASH  

I was actually in doubt about those ;-)

Btw, when producing HTML documentation,  Sphinx should convert:
	-- into EN DASH
and:
	--- into EM DASH

So, the resulting html will be identical.

> Or do you fear the extra work as some lines then might break the
> 80-character limit then?

No, I suspect that the line size won't be an issue. Some care should
taken when EN DASH and EM DASH are used inside tables.

Thanks,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 13:19:50 +0200
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu:

> Em Mon, 10 May 2021 12:52:44 +0200
> Thorsten Leemhuis <linux@leemhuis.info> escreveu:
> 
> > On 10.05.21 12:26, Mauro Carvalho Chehab wrote:  
> > >
> > > As Linux developers are all around the globe, and not everybody has UTF-8
> > > as their default charset, better to use UTF-8 only on cases where it is really
> > > needed.
> > > […]
> > > The remaining patches on series address such cases on *.rst files and 
> > > inside the Documentation/ABI, using this perl map table in order to do the
> > > charset conversion:
> > > 
> > > my %char_map = (
> > > […]
> > > 	0x2013 => '-',		# EN DASH
> > > 	0x2014 => '-',		# EM DASH    
> 
> 
> > I might be performing bike shedding here, but wouldn't it be better to
> > replace those two with "--", as explained in
> > https://en.wikipedia.org/wiki/Dash#Approximating_the_em_dash_with_two_or_three_hyphens
> > 
> > For EM DASH there seems to be even "---", but I'd say that is a bit too
> > much.  
> 
> Yeah, we can do, instead:
> 
>  	0x2013 => '--',		# EN DASH
>  	0x2014 => '---',	# EM DASH  
> 
> I was actually in doubt about those ;-)

On a quick test, I changed my script to use "--" and "---" for
EN/EM DASH chars.

The diff below is against both versions.

There are a couple of places where it got mathematically wrong, 
like this one:

	-operation over a temperature range of -40°C to +125°C.
	+operation over a temperature range of --40°C to +125°C.

On others, it is just a matter of personal taste. My personal opinion
is that, on most cases, a single "-" would be better.

Thanks,
Mauro

diff --git a/Documentation/ABI/testing/sysfs-class-net-cdc_ncm b/Documentation/ABI/testing/sysfs-class-net-cdc_ncm
index 41a1eef0d0e7..469325255887 100644
--- a/Documentation/ABI/testing/sysfs-class-net-cdc_ncm
+++ b/Documentation/ABI/testing/sysfs-class-net-cdc_ncm
@@ -93,7 +93,7 @@ Contact:	Bjørn Mork <bjorn@mork.no>
 Description:
 		- Bit 0: 16-bit NTB supported (set to 1)
 		- Bit 1: 32-bit NTB supported
-		- Bits 2 - 15: reserved (reset to zero; must be ignored by host)
+		- Bits 2 -- 15: reserved (reset to zero; must be ignored by host)
 
 What:		/sys/class/net/<iface>/cdc_ncm/dwNtbInMaxSize
 Date:		May 2014
diff --git a/Documentation/PCI/acpi-info.rst b/Documentation/PCI/acpi-info.rst
index 9b4b04039982..7a75f1f6e73c 100644
--- a/Documentation/PCI/acpi-info.rst
+++ b/Documentation/PCI/acpi-info.rst
@@ -140,8 +140,8 @@ address always corresponds to bus 0, even if the bus range below the bridge
     Extended Address Space Descriptor (.4)
       General Flags: Bit [0] Consumer/Producer:
 
-        * 1 - This device consumes this resource
-        * 0 - This device produces and consumes this resource
+        * 1 -- This device consumes this resource
+        * 0 -- This device produces and consumes this resource
 
 [5] ACPI 6.2, sec 19.6.43:
     ResourceUsage specifies whether the Memory range is consumed by
diff --git a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
index d76c6bfdc659..34a12b12df51 100644
--- a/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
+++ b/Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst
@@ -215,7 +215,7 @@ newly arrived RCU callbacks against future grace periods:
    43 }
 
 But the only part of ``rcu_prepare_for_idle()`` that really matters for
-this discussion are lines 37-39. We will therefore abbreviate this
+this discussion are lines 37--39. We will therefore abbreviate this
 function as follows:
 
 .. kernel-figure:: rcu_node-lock.svg
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
index a3493b34f3dd..a42dc3cf26bd 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.rst
+++ b/Documentation/RCU/Design/Requirements/Requirements.rst
@@ -2354,8 +2354,8 @@ which in practice also means that RCU must have an aggressive
 stress-test suite. This stress-test suite is called ``rcutorture``.
 
 Although the need for ``rcutorture`` was no surprise, the current
-immense popularity of the Linux kernel is posing interesting-and perhaps
-unprecedented-validation challenges. To see this, keep in mind that
+immense popularity of the Linux kernel is posing interesting---and perhaps
+unprecedented---validation challenges. To see this, keep in mind that
 there are well over one billion instances of the Linux kernel running
 today, given Android smartphones, Linux-powered televisions, and
 servers. This number can be expected to increase sharply with the advent
diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
index b1692643718d..1a6dbda71ad6 100644
--- a/Documentation/admin-guide/index.rst
+++ b/Documentation/admin-guide/index.rst
@@ -3,7 +3,7 @@ The Linux kernel user's and administrator's guide
 
 The following is a collection of user-oriented documents that have been
 added to the kernel over time.  There is, as yet, little overall order or
-organization here - this material was not written to be a single, coherent
+organization here --- this material was not written to be a single, coherent
 document!  With luck things will improve quickly over time.
 
 This initial section contains overall information, including the README
diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst
index bd1d2fef78e8..0d185ba8b8b5 100644
--- a/Documentation/admin-guide/module-signing.rst
+++ b/Documentation/admin-guide/module-signing.rst
@@ -100,8 +100,8 @@ This has a number of options available:
      ``certs/signing_key.pem`` will disable the autogeneration of signing keys
      and allow the kernel modules to be signed with a key of your choosing.
      The string provided should identify a file containing both a private key
-     and its corresponding X.509 certificate in PEM form, or - on systems where
-     the OpenSSL ENGINE_pkcs11 is functional - a PKCS#11 URI as defined by
+     and its corresponding X.509 certificate in PEM form, or --- on systems where
+     the OpenSSL ENGINE_pkcs11 is functional --- a PKCS#11 URI as defined by
      RFC7512. In the latter case, the PKCS#11 URI should reference both a
      certificate and a private key.
 
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst
index 00445adf8708..66c2c62c1cd4 100644
--- a/Documentation/admin-guide/ras.rst
+++ b/Documentation/admin-guide/ras.rst
@@ -40,10 +40,10 @@ it causes data loss or system downtime.
 
 Among the monitoring measures, the most usual ones include:
 
-* CPU - detect errors at instruction execution and at L1/L2/L3 caches;
-* Memory - add error correction logic (ECC) to detect and correct errors;
-* I/O - add CRC checksums for transferred data;
-* Storage - RAID, journal file systems, checksums,
+* CPU -- detect errors at instruction execution and at L1/L2/L3 caches;
+* Memory -- add error correction logic (ECC) to detect and correct errors;
+* I/O -- add CRC checksums for transferred data;
+* Storage -- RAID, journal file systems, checksums,
   Self-Monitoring, Analysis and Reporting Technology (SMART).
 
 By monitoring the number of occurrences of error detections, it is possible
diff --git a/Documentation/admin-guide/reporting-issues.rst b/Documentation/admin-guide/reporting-issues.rst
index f691930e13c0..af699015d266 100644
--- a/Documentation/admin-guide/reporting-issues.rst
+++ b/Documentation/admin-guide/reporting-issues.rst
@@ -824,7 +824,7 @@ and look a little lower at the table. At its top you'll see a line starting with
 mainline, which most of the time will point to a pre-release with a version
 number like '5.8-rc2'. If that's the case, you'll want to use this mainline
 kernel for testing, as that where all fixes have to be applied first. Do not let
-that 'rc' scare you, these 'development kernels' are pretty reliable - and you
+that 'rc' scare you, these 'development kernels' are pretty reliable --- and you
 made a backup, as you were instructed above, didn't you?
 
 In about two out of every nine to ten weeks, mainline might point you to a
@@ -866,7 +866,7 @@ How to obtain a fresh Linux kernel
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 **Using a pre-compiled kernel**: This is often the quickest, easiest, and safest
-way for testing - especially is you are unfamiliar with the Linux kernel. The
+way for testing --- especially is you are unfamiliar with the Linux kernel. The
 problem: most of those shipped by distributors or add-on repositories are build
 from modified Linux sources. They are thus not vanilla and therefore often
 unsuitable for testing and issue reporting: the changes might cause the issue
@@ -1345,7 +1345,7 @@ about it to a chatroom or forum you normally hang out.
 
 **Be patient**: If you are really lucky you might get a reply to your report
 within a few hours. But most of the time it will take longer, as maintainers
-are scattered around the globe and thus might be in a different time zone - one
+are scattered around the globe and thus might be in a different time zone -- one
 where they already enjoy their night away from keyboard.
 
 In general, kernel developers will take one to five business days to respond to
@@ -1388,7 +1388,7 @@ Here are your duties in case you got replies to your report:
 
 **Check who you deal with**: Most of the time it will be the maintainer or a
 developer of the particular code area that will respond to your report. But as
-issues are normally reported in public it could be anyone that's replying -
+issues are normally reported in public it could be anyone that's replying ---
 including people that want to help, but in the end might guide you totally off
 track with their questions or requests. That rarely happens, but it's one of
 many reasons why it's wise to quickly run an internet search to see who you're
@@ -1716,7 +1716,7 @@ Maybe their test hardware broke, got replaced by something more fancy, or is so
 old that it's something you don't find much outside of computer museums
 anymore. Sometimes developer stops caring for their code and Linux at all, as
 something different in their life became way more important. In some cases
-nobody is willing to take over the job as maintainer - and nobody can be forced
+nobody is willing to take over the job as maintainer -- and nobody can be forced
 to, as contributing to the Linux kernel is done on a voluntary basis. Abandoned
 drivers nevertheless remain in the kernel: they are still useful for people and
 removing would be a regression.
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 743a7c70fd83..639dd58518ca 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1285,7 +1285,7 @@ The soft lockup detector monitors CPUs for threads that are hogging the CPUs
 without rescheduling voluntarily, and thus prevent the 'watchdog/N' threads
 from running. The mechanism depends on the CPUs ability to respond to timer
 interrupts which are needed for the 'watchdog/N' threads to be woken up by
-the watchdog timer function, otherwise the NMI watchdog - if enabled - can
+the watchdog timer function, otherwise the NMI watchdog --- if enabled --- can
 detect a hard lockup condition.
 
 
diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst
index 8adffc26a2ec..381c571eb52c 100644
--- a/Documentation/dev-tools/testing-overview.rst
+++ b/Documentation/dev-tools/testing-overview.rst
@@ -18,8 +18,8 @@ frameworks. These both provide infrastructure to help make running tests and
 groups of tests easier, as well as providing helpers to aid in writing new
 tests.
 
-If you're looking to verify the behaviour of the Kernel - particularly specific
-parts of the kernel - then you'll want to use KUnit or kselftest.
+If you're looking to verify the behaviour of the Kernel --- particularly specific
+parts of the kernel --- then you'll want to use KUnit or kselftest.
 
 
 The Difference Between KUnit and kselftest
diff --git a/Documentation/doc-guide/contributing.rst b/Documentation/doc-guide/contributing.rst
index c2d709467c68..ac5c9f1d2311 100644
--- a/Documentation/doc-guide/contributing.rst
+++ b/Documentation/doc-guide/contributing.rst
@@ -76,7 +76,7 @@ comments that look like this::
 
 The problem is the missing "*", which confuses the build system's
 simplistic idea of what C comment blocks look like.  This problem had been
-present since that comment was added in 2016 - a full four years.  Fixing
+present since that comment was added in 2016 --- a full four years.  Fixing
 it was a matter of adding the missing asterisks.  A quick look at the
 history for that file showed what the normal format for subject lines is,
 and ``scripts/get_maintainer.pl`` told me who should receive it.  The
diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
index 8d650b4e2ce6..1d6e910c27df 100644
--- a/Documentation/driver-api/fpga/fpga-bridge.rst
+++ b/Documentation/driver-api/fpga/fpga-bridge.rst
@@ -4,11 +4,11 @@ FPGA Bridge
 API to implement a new FPGA bridge
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* struct fpga_bridge - The FPGA Bridge structure
-* struct fpga_bridge_ops - Low level Bridge driver ops
-* devm_fpga_bridge_create() - Allocate and init a bridge struct
-* fpga_bridge_register() - Register a bridge
-* fpga_bridge_unregister() - Unregister a bridge
+* struct fpga_bridge --- The FPGA Bridge structure
+* struct fpga_bridge_ops --- Low level Bridge driver ops
+* devm_fpga_bridge_create() --- Allocate and init a bridge struct
+* fpga_bridge_register() --- Register a bridge
+* fpga_bridge_unregister() --- Unregister a bridge
 
 .. kernel-doc:: include/linux/fpga/fpga-bridge.h
    :functions: fpga_bridge
diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
index 4d926b452cb3..272161361c6a 100644
--- a/Documentation/driver-api/fpga/fpga-mgr.rst
+++ b/Documentation/driver-api/fpga/fpga-mgr.rst
@@ -101,12 +101,12 @@ in state.
 API for implementing a new FPGA Manager driver
 ----------------------------------------------
 
-* ``fpga_mgr_states`` -  Values for :c:expr:`fpga_manager->state`.
-* struct fpga_manager -  the FPGA manager struct
-* struct fpga_manager_ops -  Low level FPGA manager driver ops
-* devm_fpga_mgr_create() -  Allocate and init a manager struct
-* fpga_mgr_register() -  Register an FPGA manager
-* fpga_mgr_unregister() -  Unregister an FPGA manager
+* ``fpga_mgr_states`` ---  Values for :c:expr:`fpga_manager->state`.
+* struct fpga_manager ---  the FPGA manager struct
+* struct fpga_manager_ops ---  Low level FPGA manager driver ops
+* devm_fpga_mgr_create() ---  Allocate and init a manager struct
+* fpga_mgr_register() ---  Register an FPGA manager
+* fpga_mgr_unregister() ---  Unregister an FPGA manager
 
 .. kernel-doc:: include/linux/fpga/fpga-mgr.h
    :functions: fpga_mgr_states
diff --git a/Documentation/driver-api/fpga/fpga-programming.rst b/Documentation/driver-api/fpga/fpga-programming.rst
index fb4da4240e96..adc725855bad 100644
--- a/Documentation/driver-api/fpga/fpga-programming.rst
+++ b/Documentation/driver-api/fpga/fpga-programming.rst
@@ -84,10 +84,10 @@ will generate that list.  Here's some sample code of what to do next::
 API for programming an FPGA
 ---------------------------
 
-* fpga_region_program_fpga() -  Program an FPGA
-* fpga_image_info() -  Specifies what FPGA image to program
-* fpga_image_info_alloc() -  Allocate an FPGA image info struct
-* fpga_image_info_free() -  Free an FPGA image info struct
+* fpga_region_program_fpga() ---  Program an FPGA
+* fpga_image_info() ---  Specifies what FPGA image to program
+* fpga_image_info_alloc() ---  Allocate an FPGA image info struct
+* fpga_image_info_free() ---  Free an FPGA image info struct
 
 .. kernel-doc:: drivers/fpga/fpga-region.c
    :functions: fpga_region_program_fpga
diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
index 2636a27c11b2..6c0c2541de04 100644
--- a/Documentation/driver-api/fpga/fpga-region.rst
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -45,19 +45,19 @@ An example of usage can be seen in the probe function of [#f2]_.
 API to add a new FPGA region
 ----------------------------
 
-* struct fpga_region - The FPGA region struct
-* devm_fpga_region_create() - Allocate and init a region struct
-* fpga_region_register() -  Register an FPGA region
-* fpga_region_unregister() -  Unregister an FPGA region
+* struct fpga_region --- The FPGA region struct
+* devm_fpga_region_create() --- Allocate and init a region struct
+* fpga_region_register() ---  Register an FPGA region
+* fpga_region_unregister() ---  Unregister an FPGA region
 
 The FPGA region's probe function will need to get a reference to the FPGA
 Manager it will be using to do the programming.  This usually would happen
 during the region's probe function.
 
-* fpga_mgr_get() - Get a reference to an FPGA manager, raise ref count
-* of_fpga_mgr_get() -  Get a reference to an FPGA manager, raise ref count,
+* fpga_mgr_get() --- Get a reference to an FPGA manager, raise ref count
+* of_fpga_mgr_get() ---  Get a reference to an FPGA manager, raise ref count,
   given a device node.
-* fpga_mgr_put() - Put an FPGA manager
+* fpga_mgr_put() --- Put an FPGA manager
 
 The FPGA region will need to specify which bridges to control while programming
 the FPGA.  The region driver can build a list of bridges during probe time
@@ -66,11 +66,11 @@ the list of bridges to program just before programming
 (:c:expr:`fpga_region->get_bridges`).  The FPGA bridge framework supplies the
 following APIs to handle building or tearing down that list.
 
-* fpga_bridge_get_to_list() - Get a ref of an FPGA bridge, add it to a
+* fpga_bridge_get_to_list() --- Get a ref of an FPGA bridge, add it to a
   list
-* of_fpga_bridge_get_to_list() - Get a ref of an FPGA bridge, add it to a
+* of_fpga_bridge_get_to_list() --- Get a ref of an FPGA bridge, add it to a
   list, given a device node
-* fpga_bridges_put() - Given a list of bridges, put them
+* fpga_bridges_put() --- Given a list of bridges, put them
 
 .. kernel-doc:: include/linux/fpga/fpga-region.h
    :functions: fpga_region
diff --git a/Documentation/driver-api/iio/buffers.rst b/Documentation/driver-api/iio/buffers.rst
index 24569ff0cf79..906dfc10b7ef 100644
--- a/Documentation/driver-api/iio/buffers.rst
+++ b/Documentation/driver-api/iio/buffers.rst
@@ -2,11 +2,11 @@
 Buffers
 =======
 
-* struct iio_buffer - general buffer structure
-* :c:func:`iio_validate_scan_mask_onehot` - Validates that exactly one channel
+* struct iio_buffer --- general buffer structure
+* :c:func:`iio_validate_scan_mask_onehot` --- Validates that exactly one channel
   is selected
-* :c:func:`iio_buffer_get` - Grab a reference to the buffer
-* :c:func:`iio_buffer_put` - Release the reference to the buffer
+* :c:func:`iio_buffer_get` --- Grab a reference to the buffer
+* :c:func:`iio_buffer_put` --- Release the reference to the buffer
 
 The Industrial I/O core offers a way for continuous data capture based on a
 trigger source. Multiple data channels can be read at once from
diff --git a/Documentation/driver-api/iio/hw-consumer.rst b/Documentation/driver-api/iio/hw-consumer.rst
index 75986358fc02..06969fde2086 100644
--- a/Documentation/driver-api/iio/hw-consumer.rst
+++ b/Documentation/driver-api/iio/hw-consumer.rst
@@ -8,11 +8,11 @@ software buffer for data. The implementation can be found under
 :file:`drivers/iio/buffer/hw-consumer.c`
 
 
-* struct iio_hw_consumer - Hardware consumer structure
-* :c:func:`iio_hw_consumer_alloc` - Allocate IIO hardware consumer
-* :c:func:`iio_hw_consumer_free` - Free IIO hardware consumer
-* :c:func:`iio_hw_consumer_enable` - Enable IIO hardware consumer
-* :c:func:`iio_hw_consumer_disable` - Disable IIO hardware consumer
+* struct iio_hw_consumer --- Hardware consumer structure
+* :c:func:`iio_hw_consumer_alloc` --- Allocate IIO hardware consumer
+* :c:func:`iio_hw_consumer_free` --- Free IIO hardware consumer
+* :c:func:`iio_hw_consumer_enable` --- Enable IIO hardware consumer
+* :c:func:`iio_hw_consumer_disable` --- Disable IIO hardware consumer
 
 
 HW consumer setup
diff --git a/Documentation/driver-api/iio/triggered-buffers.rst b/Documentation/driver-api/iio/triggered-buffers.rst
index 7c37b2afa1ad..49831ff466c5 100644
--- a/Documentation/driver-api/iio/triggered-buffers.rst
+++ b/Documentation/driver-api/iio/triggered-buffers.rst
@@ -7,10 +7,10 @@ Now that we know what buffers and triggers are let's see how they work together.
 IIO triggered buffer setup
 ==========================
 
-* :c:func:`iio_triggered_buffer_setup` - Setup triggered buffer and pollfunc
-* :c:func:`iio_triggered_buffer_cleanup` - Free resources allocated by
+* :c:func:`iio_triggered_buffer_setup` --- Setup triggered buffer and pollfunc
+* :c:func:`iio_triggered_buffer_cleanup` --- Free resources allocated by
   :c:func:`iio_triggered_buffer_setup`
-* struct iio_buffer_setup_ops - buffer setup related callbacks
+* struct iio_buffer_setup_ops --- buffer setup related callbacks
 
 A typical triggered buffer setup looks like this::
 
diff --git a/Documentation/driver-api/iio/triggers.rst b/Documentation/driver-api/iio/triggers.rst
index a5d1fc15747c..5b3d475bc871 100644
--- a/Documentation/driver-api/iio/triggers.rst
+++ b/Documentation/driver-api/iio/triggers.rst
@@ -2,11 +2,11 @@
 Triggers
 ========
 
-* struct iio_trigger - industrial I/O trigger device
-* :c:func:`devm_iio_trigger_alloc` - Resource-managed iio_trigger_alloc
-* :c:func:`devm_iio_trigger_register` - Resource-managed iio_trigger_register
+* struct iio_trigger --- industrial I/O trigger device
+* :c:func:`devm_iio_trigger_alloc` --- Resource-managed iio_trigger_alloc
+* :c:func:`devm_iio_trigger_register` --- Resource-managed iio_trigger_register
   iio_trigger_unregister
-* :c:func:`iio_trigger_validate_own_device` - Check if a trigger and IIO
+* :c:func:`iio_trigger_validate_own_device` --- Check if a trigger and IIO
   device belong to the same device
 
 In many situations it is useful for a driver to be able to capture data based
@@ -63,7 +63,7 @@ Let's see a simple example of how to setup a trigger to be used by a driver::
 IIO trigger ops
 ===============
 
-* struct iio_trigger_ops - operations structure for an iio_trigger.
+* struct iio_trigger_ops --- operations structure for an iio_trigger.
 
 Notice that a trigger has a set of operations attached:
 
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index 29eb9230b7a9..e07e0d39c7f0 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -4,7 +4,7 @@ The Linux driver implementer's API guide
 
 The kernel offers a wide variety of interfaces to support the development
 of device drivers.  This document is an only somewhat organized collection
-of some of those interfaces - it will hopefully get better over time!  The
+of some of those interfaces --- it will hopefully get better over time!  The
 available subsections can be seen below.
 
 .. class:: toc-title
diff --git a/Documentation/driver-api/media/drivers/vidtv.rst b/Documentation/driver-api/media/drivers/vidtv.rst
index abb454302ac5..c3821d82df17 100644
--- a/Documentation/driver-api/media/drivers/vidtv.rst
+++ b/Documentation/driver-api/media/drivers/vidtv.rst
@@ -458,8 +458,8 @@ Add a way to test video
 
 Currently, vidtv can only encode PCM audio. It would be great to implement
 a barebones version of MPEG-2 video encoding so we can also test video. The
-first place to look into is *ISO 13818-2: Information technology - Generic
-coding of moving pictures and associated audio information - Part 2: Video*,
+first place to look into is *ISO 13818-2: Information technology --- Generic
+coding of moving pictures and associated audio information --- Part 2: Video*,
 which covers the encoding of compressed video in MPEG Transport Streams.
 
 This might optionally use the Video4Linux2 Test Pattern Generator, v4l2-tpg,
diff --git a/Documentation/driver-api/nvdimm/btt.rst b/Documentation/driver-api/nvdimm/btt.rst
index dd91a495e02e..1d2d9cd40def 100644
--- a/Documentation/driver-api/nvdimm/btt.rst
+++ b/Documentation/driver-api/nvdimm/btt.rst
@@ -91,7 +91,7 @@ Bit      Description
 	   0  0	  Initial state. Reads return zeroes; Premap = Postmap
 	   0  1	  Zero state: Reads return zeroes
 	   1  0	  Error state: Reads fail; Writes clear 'E' bit
-	   1  1	  Normal Block - has valid postmap
+	   1  1	  Normal Block -- has valid postmap
 	   == ==  ====================================================
 
 29 - 0	 Mappings to internal 'postmap' blocks
diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
index 19d2cf477fc3..9b0e9abf8f88 100644
--- a/Documentation/filesystems/f2fs.rst
+++ b/Documentation/filesystems/f2fs.rst
@@ -42,7 +42,7 @@ areas on disk for fast writing, we divide  the log into segments and use a
 segment cleaner to compress the live information from heavily fragmented
 segments." from Rosenblum, M. and Ousterhout, J. K., 1992, "The design and
 implementation of a log-structured file system", ACM Trans. Computer Systems
-10, 1, 26-52.
+10, 1, 26--52.
 
 Wandering Tree Problem
 ----------------------
diff --git a/Documentation/hwmon/tmp103.rst b/Documentation/hwmon/tmp103.rst
index b3ef81475cf8..051282bd88b7 100644
--- a/Documentation/hwmon/tmp103.rst
+++ b/Documentation/hwmon/tmp103.rst
@@ -21,10 +21,10 @@ Description
 The TMP103 is a digital output temperature sensor in a four-ball
 wafer chip-scale package (WCSP). The TMP103 is capable of reading
 temperatures to a resolution of 1°C. The TMP103 is specified for
-operation over a temperature range of -40°C to +125°C.
+operation over a temperature range of --40°C to +125°C.
 
 Resolution: 8 Bits
-Accuracy: ±1°C Typ (-10°C to +100°C)
+Accuracy: ±1°C Typ (--10°C to +100°C)
 
 The driver provides the common sysfs-interface for temperatures (see
 Documentation/hwmon/sysfs-interface.rst under Temperatures).
diff --git a/Documentation/index.rst b/Documentation/index.rst
index 11cd806ea3a4..7ae88aa57d98 100644
--- a/Documentation/index.rst
+++ b/Documentation/index.rst
@@ -30,7 +30,7 @@ tree, as well as links to the full license text.
 User-oriented documentation
 ---------------------------
 
-The following manuals are written for *users* of the kernel - those who are
+The following manuals are written for *users* of the kernel --- those who are
 trying to get it to work optimally on a given system.
 
 .. toctree::
@@ -90,7 +90,7 @@ Kernel API documentation
 These books get into the details of how specific kernel subsystems work
 from the point of view of a kernel developer.  Much of the information here
 is taken directly from the kernel source, with supplemental material added
-as needed (or at least as we managed to add it - probably *not* all that is
+as needed (or at least as we managed to add it --- probably *not* all that is
 needed).
 
 .. toctree::
diff --git a/Documentation/infiniband/tag_matching.rst b/Documentation/infiniband/tag_matching.rst
index b89528a31d10..2c26f76e43f9 100644
--- a/Documentation/infiniband/tag_matching.rst
+++ b/Documentation/infiniband/tag_matching.rst
@@ -8,8 +8,8 @@ match the following source and destination parameters:
 
 *	Communicator
 *	User tag - wild card may be specified by the receiver
-*	Source rank - wild car may be specified by the receiver
-*	Destination rank - wild
+*	Source rank -- wild car may be specified by the receiver
+*	Destination rank -- wild
 
 The ordering rules require that when more than one pair of send and receive
 message envelopes may match, the pair that includes the earliest posted-send
diff --git a/Documentation/networking/device_drivers/ethernet/intel/i40e.rst b/Documentation/networking/device_drivers/ethernet/intel/i40e.rst
index 64024c77c9ca..e3e52b0e6b5e 100644
--- a/Documentation/networking/device_drivers/ethernet/intel/i40e.rst
+++ b/Documentation/networking/device_drivers/ethernet/intel/i40e.rst
@@ -173,7 +173,7 @@ Director rule is added from ethtool (Sideband filter), ATR is turned off by the
 driver. To re-enable ATR, the sideband can be disabled with the ethtool -K
 option. For example::
 
-  ethtool -K [adapter] ntuple [off|on]
+  ethtool --K [adapter] ntuple [off|on]
 
 If sideband is re-enabled after ATR is re-enabled, ATR remains enabled until a
 TCP-IP flow is added. When all TCP-IP sideband rules are deleted, ATR is
@@ -688,7 +688,7 @@ shaper bw_rlimit: for each tc, sets minimum and maximum bandwidth rates.
 Totals must be equal or less than port speed.
 
 For example: min_rate 1Gbit 3Gbit: Verify bandwidth limit using network
-monitoring tools such as ifstat or sar -n DEV [interval] [number of samples]
+monitoring tools such as ifstat or sar --n DEV [interval] [number of samples]
 
 2. Enable HW TC offload on interface::
 
diff --git a/Documentation/networking/device_drivers/ethernet/intel/iavf.rst b/Documentation/networking/device_drivers/ethernet/intel/iavf.rst
index 25e98494b385..44d2f85738b1 100644
--- a/Documentation/networking/device_drivers/ethernet/intel/iavf.rst
+++ b/Documentation/networking/device_drivers/ethernet/intel/iavf.rst
@@ -179,7 +179,7 @@ shaper bw_rlimit: for each tc, sets minimum and maximum bandwidth rates.
 Totals must be equal or less than port speed.
 
 For example: min_rate 1Gbit 3Gbit: Verify bandwidth limit using network
-monitoring tools such as ifstat or sar -n DEV [interval] [number of samples]
+monitoring tools such as ifstat or sar --n DEV [interval] [number of samples]
 
 NOTE:
   Setting up channels via ethtool (ethtool -L) is not supported when the
diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst
index 545f8ab51f1a..05615b3021bb 100644
--- a/Documentation/riscv/vm-layout.rst
+++ b/Documentation/riscv/vm-layout.rst
@@ -22,7 +22,7 @@ RISC-V Linux Kernel 64bit
 =========================
 
 The RISC-V privileged architecture document states that the 64bit addresses
-"must have bits 63-48 all equal to bit 47, or else a page-fault exception will
+"must have bits 63--48 all equal to bit 47, or else a page-fault exception will
 occur.": that splits the virtual address space into 2 halves separated by a very
 big hole, the lower half is where the userspace resides, the upper half is where
 the RISC-V Linux Kernel resides.
diff --git a/Documentation/scheduler/sched-deadline.rst b/Documentation/scheduler/sched-deadline.rst
index 0ff353ecf24e..b261ec2ab2ef 100644
--- a/Documentation/scheduler/sched-deadline.rst
+++ b/Documentation/scheduler/sched-deadline.rst
@@ -515,7 +515,7 @@ Deadline Task Scheduling
       pp 760-768, 2005.
   10 - J. Goossens, S. Funk and S. Baruah, Priority-Driven Scheduling of
        Periodic Task Systems on Multiprocessors. Real-Time Systems Journal,
-       vol. 25, no. 2-3, pp. 187-205, 2003.
+       vol. 25, no. 2--3, pp. 187--205, 2003.
   11 - R. Davis and A. Burns. A Survey of Hard Real-Time Scheduling for
        Multiprocessor Systems. ACM Computing Surveys, vol. 43, no. 4, 2011.
        http://www-users.cs.york.ac.uk/~robdavis/papers/MPSurveyv5.0.pdf
diff --git a/Documentation/userspace-api/media/v4l/biblio.rst b/Documentation/userspace-api/media/v4l/biblio.rst
index 6e07b78bd39d..7b8e6738ff9e 100644
--- a/Documentation/userspace-api/media/v4l/biblio.rst
+++ b/Documentation/userspace-api/media/v4l/biblio.rst
@@ -51,7 +51,7 @@ ISO 13818-1
 ===========
 
 
-:title:     ITU-T Rec. H.222.0 | ISO/IEC 13818-1 "Information technology - Generic coding of moving pictures and associated audio information: Systems"
+:title:     ITU-T Rec. H.222.0 | ISO/IEC 13818-1 "Information technology --- Generic coding of moving pictures and associated audio information: Systems"
 
 :author:    International Telecommunication Union (http://www.itu.ch), International Organisation for Standardisation (http://www.iso.ch)
 
@@ -61,7 +61,7 @@ ISO 13818-2
 ===========
 
 
-:title:     ITU-T Rec. H.262 | ISO/IEC 13818-2 "Information technology - Generic coding of moving pictures and associated audio information: Video"
+:title:     ITU-T Rec. H.262 | ISO/IEC 13818-2 "Information technology --- Generic coding of moving pictures and associated audio information: Video"
 
 :author:    International Telecommunication Union (http://www.itu.ch), International Organisation for Standardisation (http://www.iso.ch)
 
@@ -150,7 +150,7 @@ ITU-T.81
 ========
 
 
-:title:     ITU-T Recommendation T.81 "Information Technology - Digital Compression and Coding of Continous-Tone Still Images - Requirements and Guidelines"
+:title:     ITU-T Recommendation T.81 "Information Technology --- Digital Compression and Coding of Continous-Tone Still Images --- Requirements and Guidelines"
 
 :author:    International Telecommunication Union (http://www.itu.int)
 
@@ -310,7 +310,7 @@ ISO 12232:2006
 ==============
 
 
-:title:     Photography - Digital still cameras - Determination of exposure index, ISO speed ratings, standard output sensitivity, and recommended exposure index
+:title:     Photography --- Digital still cameras --- Determination of exposure index, ISO speed ratings, standard output sensitivity, and recommended exposure index
 
 :author:    International Organization for Standardization (http://www.iso.org)
 
diff --git a/Documentation/virt/kvm/running-nested-guests.rst b/Documentation/virt/kvm/running-nested-guests.rst
index e9dff3fea055..8b83b86560da 100644
--- a/Documentation/virt/kvm/running-nested-guests.rst
+++ b/Documentation/virt/kvm/running-nested-guests.rst
@@ -26,12 +26,12 @@ this document is built on this example)::
 
 Terminology:
 
-- L0 - level-0; the bare metal host, running KVM
+- L0 -- level-0; the bare metal host, running KVM
 
-- L1 - level-1 guest; a VM running on L0; also called the "guest
+- L1 -- level-1 guest; a VM running on L0; also called the "guest
   hypervisor", as it itself is capable of running KVM.
 
-- L2 - level-2 guest; a VM running on L1, this is the "nested guest"
+- L2 -- level-2 guest; a VM running on L1, this is the "nested guest"
 
 .. note:: The above diagram is modelled after the x86 architecture;
           s390x, ppc64 and other architectures are likely to have
@@ -39,7 +39,7 @@ Terminology:
 
           For example, s390x always has an LPAR (LogicalPARtition)
           hypervisor running on bare metal, adding another layer and
-          resulting in at least four levels in a nested setup - L0 (bare
+          resulting in at least four levels in a nested setup --- L0 (bare
           metal, running the LPAR hypervisor), L1 (host hypervisor), L2
           (guest hypervisor), L3 (nested guest).
 
@@ -167,11 +167,11 @@ Enabling "nested" (s390x)
     $ modprobe kvm nested=1
 
 .. note:: On s390x, the kernel parameter ``hpage`` is mutually exclusive
-          with the ``nested`` paramter - i.e. to be able to enable
+          with the ``nested`` paramter --- i.e. to be able to enable
           ``nested``, the ``hpage`` parameter *must* be disabled.
 
 2. The guest hypervisor (L1) must be provided with the ``sie`` CPU
-   feature - with QEMU, this can be done by using "host passthrough"
+   feature --- with QEMU, this can be done by using "host passthrough"
    (via the command-line ``-cpu host``).
 
 3. Now the KVM module can be loaded in the L1 (guest hypervisor)::

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[David Woodhouse]

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On Mon, 2021-05-10 at 12:26 +0200, Mauro Carvalho Chehab wrote:
> There are several UTF-8 characters at the Kernel's documentation.
> 
> Several of them were due to the process of converting files from
> DocBook, LaTeX, HTML and Markdown. They were probably introduced
> by the conversion tools used on that time.
> 
> Other UTF-8 characters were added along the time, but they're easily
> replaceable by ASCII chars.
> 
> As Linux developers are all around the globe, and not everybody has UTF-8
> as their default charset, better to use UTF-8 only on cases where it is really
> needed.

No, that is absolutely the wrong approach.

If someone has a local setup which makes bogus assumptions about text
encodings, that is their own mistake.

We don't do them any favours by trying to *hide* it in the common case
so that they don't notice it for longer.

There really isn't much excuse for such brokenness, this far into the
21st century.

Even *before* UTF-8 came along in the final decade of the last
millennium, it was important to know which character set a given piece
of text was encoded in.

In fact it was even *more* important back then, we couldn't just assume
UTF-8 everywhere like we can in modern times.

Git can already do things like CRLF conversion on checking files out to
match local conventions; if you want to teach it to do character set
conversions too then I suppose that might be useful to a few developers
who've fallen through a time warp and still need it. But nobody's ever
bothered before because it just isn't necessary these days.

Please *don't* attempt to address this anachronistic and esoteric
"requirement" by dragging the kernel source back in time by three
decades.



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Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Hi David,

Em Mon, 10 May 2021 11:54:02 +0100
David Woodhouse <dwmw2@infradead.org> escreveu:

> On Mon, 2021-05-10 at 12:26 +0200, Mauro Carvalho Chehab wrote:
> > There are several UTF-8 characters at the Kernel's documentation.
> > 
> > Several of them were due to the process of converting files from
> > DocBook, LaTeX, HTML and Markdown. They were probably introduced
> > by the conversion tools used on that time.
> > 
> > Other UTF-8 characters were added along the time, but they're easily
> > replaceable by ASCII chars.
> > 
> > As Linux developers are all around the globe, and not everybody has UTF-8
> > as their default charset, better to use UTF-8 only on cases where it is really
> > needed.  
> 
> No, that is absolutely the wrong approach.
> 
> If someone has a local setup which makes bogus assumptions about text
> encodings, that is their own mistake.
> 
> We don't do them any favours by trying to *hide* it in the common case
> so that they don't notice it for longer.
> 
> There really isn't much excuse for such brokenness, this far into the
> 21st century.
> 
> Even *before* UTF-8 came along in the final decade of the last
> millennium, it was important to know which character set a given piece
> of text was encoded in.
> 
> In fact it was even *more* important back then, we couldn't just assume
> UTF-8 everywhere like we can in modern times.
> 
> Git can already do things like CRLF conversion on checking files out to
> match local conventions; if you want to teach it to do character set
> conversions too then I suppose that might be useful to a few developers
> who've fallen through a time warp and still need it. But nobody's ever
> bothered before because it just isn't necessary these days.
> 
> Please *don't* attempt to address this anachronistic and esoteric
> "requirement" by dragging the kernel source back in time by three
> decades.

No. The idea is not to go back three decades ago. 

The goal is just to avoid use UTF-8 where it is not needed. See, the vast
majority of UTF-8 chars are kept:

	- Non-ASCII Latin and Greek chars;
	- Box drawings;
	- arrows;
	- most symbols.

There, it makes perfect sense to keep using UTF-8.

We should keep using UTF-8 on Kernel. This is something that it shouldn't
be changed.

---

This patch series is doing conversion only when using ASCII makes
more sense than using UTF-8. 

See, a number of converted documents ended with weird characters
like ZERO WIDTH NO-BREAK SPACE (U+FEFF) character. This specific
character doesn't do any good.

Others use NO-BREAK SPACE (U+A0) instead of 0x20. Harmless, until
someone tries to use grep[1].

[1] try to run:

    $ git grep "CPU 0 has been" Documentation/RCU/

    it will return nothing with current upstream.

    But it will work fine after the series is applied:

    $ git grep "CPU 0 has been" Documentation/RCU/
      Documentation/RCU/Design/Data-Structures/Data-Structures.rst:| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
      Documentation/RCU/Design/Data-Structures/Data-Structures.rst:|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |

The main point on this series is to replace just the occurrences
where ASCII represents the symbol equally well, e. g. it is limited
for those chars:

	- U+2010 ('‐'): HYPHEN
	- U+00ad ('­'): SOFT HYPHEN
	- U+2013 ('–'): EN DASH
	- U+2014 ('—'): EM DASH

	- U+2018 ('‘'): LEFT SINGLE QUOTATION MARK
	- U+2019 ('’'): RIGHT SINGLE QUOTATION MARK
	- U+00b4 ('´'): ACUTE ACCENT

	- U+201c ('“'): LEFT DOUBLE QUOTATION MARK
	- U+201d ('”'): RIGHT DOUBLE QUOTATION MARK

	- U+00d7 ('×'): MULTIPLICATION SIGN
	- U+2212 ('−'): MINUS SIGN

	- U+2217 ('∗'): ASTERISK OPERATOR
	  (this one used as a pointer reference like "*foo" on C code
	   example inside a document converted from LaTeX)

	- U+00bb ('»'): RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
	  (this one also used wrongly on an ABI file, meaning '>')

	- U+00a0 (' '): NO-BREAK SPACE
	- U+feff (''): ZERO WIDTH NO-BREAK SPACE

Using the above symbols will just trick tools like grep for no good
reason.

Thanks,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Edward Cree]

On 10/05/2021 12:55, Mauro Carvalho Chehab wrote:
> The main point on this series is to replace just the occurrences
> where ASCII represents the symbol equally well

> 	- U+2014 ('—'): EM DASH
Em dash is not the same thing as hyphen-minus, and the latter does not
 serve 'equally well'.  People use em dashes because — even in
 monospace fonts — they make text easier to read and comprehend, when
 used correctly.
I accept that some of the other distinctions — like en dashes — are
 needlessly pedantic (though I don't doubt there is someone out there
 who will gladly defend them with the same fervour with which I argue
 for the em dash) and I wouldn't take the trouble to use them myself;
 but I think there is a reasonable assumption that when someone goes
 to the effort of using a Unicode punctuation mark that is semantic
 (rather than merely typographical), they probably had a reason for
 doing so.

> 	- U+2018 ('‘'): LEFT SINGLE QUOTATION MARK
> 	- U+2019 ('’'): RIGHT SINGLE QUOTATION MARK
> 	- U+201c ('“'): LEFT DOUBLE QUOTATION MARK
> 	- U+201d ('”'): RIGHT DOUBLE QUOTATION MARK
(These are purely typographic, I have no problem with dumping them.)

> 	- U+00d7 ('×'): MULTIPLICATION SIGN
Presumably this is appearing in mathematical formulae, in which case
 changing it to 'x' loses semantic information.

> Using the above symbols will just trick tools like grep for no good
> reason.
NBSP, sure.  That one's probably an artefact of some document format
 conversion somewhere along the line, anyway.
But what kinds of things with × or — in are going to be grept for?

If there are em dashes lying around that semantically _should_ be
 hyphen-minus (one of your patches I've seen, for instance, fixes an
 *en* dash moonlighting as the option character in an `ethtool`
 command line), then sure, convert them.
But any time someone is using a Unicode character to *express
 semantics*, even if you happen to think the semantic distinction
 involved is a pedantic or unimportant one, I think you need an
 explicit grep case to justify ASCIIfying it.

-ed

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 14:16:16 +0100
Edward Cree <ecree.xilinx@gmail.com> escreveu:

> On 10/05/2021 12:55, Mauro Carvalho Chehab wrote:
> > The main point on this series is to replace just the occurrences
> > where ASCII represents the symbol equally well  
> 
> > 	- U+2014 ('—'): EM DASH  
> Em dash is not the same thing as hyphen-minus, and the latter does not
>  serve 'equally well'.  People use em dashes because — even in
>  monospace fonts — they make text easier to read and comprehend, when
>  used correctly.

True, but if you look at the diff, on several places, IMHO a single
hyphen would make more sensus. Maybe those places came from a converted
doc.

> I accept that some of the other distinctions — like en dashes — are
>  needlessly pedantic (though I don't doubt there is someone out there
>  who will gladly defend them with the same fervour with which I argue
>  for the em dash) and I wouldn't take the trouble to use them myself;
>  but I think there is a reasonable assumption that when someone goes
>  to the effort of using a Unicode punctuation mark that is semantic
>  (rather than merely typographical), they probably had a reason for
>  doing so.
> 
> > 	- U+2018 ('‘'): LEFT SINGLE QUOTATION MARK
> > 	- U+2019 ('’'): RIGHT SINGLE QUOTATION MARK
> > 	- U+201c ('“'): LEFT DOUBLE QUOTATION MARK
> > 	- U+201d ('”'): RIGHT DOUBLE QUOTATION MARK  
> (These are purely typographic, I have no problem with dumping them.)
> 
> > 	- U+00d7 ('×'): MULTIPLICATION SIGN  
> Presumably this is appearing in mathematical formulae, in which case
>  changing it to 'x' loses semantic information.
> 
> > Using the above symbols will just trick tools like grep for no good
> > reason.  
> NBSP, sure.  That one's probably an artefact of some document format
>  conversion somewhere along the line, anyway.
> But what kinds of things with × or — in are going to be grept for?

Actually, on almost all places, those aren't used inside math formulae, but
instead, they describe video some resolutions:

	$ git grep × Documentation/
	Documentation/devicetree/bindings/display/panel/asus,z00t-tm5p5-nt35596.yaml:title: ASUS Z00T TM5P5 NT35596 5.5" 1080×1920 LCD Panel
	Documentation/devicetree/bindings/display/panel/panel-simple-dsi.yaml:        # LG ACX467AKM-7 4.95" 1080×1920 LCD Panel
	Documentation/devicetree/bindings/sound/tlv320adcx140.yaml:      1 - Mic bias is set to VREF × 1.096
	Documentation/userspace-api/media/v4l/crop.rst:of 16 × 16 pixels. The source cropping rectangle is set to defaults,
	Documentation/userspace-api/media/v4l/crop.rst:which are also the upper limit in this example, of 640 × 400 pixels at
	Documentation/userspace-api/media/v4l/crop.rst:offset 0, 0. An application requests an image size of 300 × 225 pixels,
	Documentation/userspace-api/media/v4l/crop.rst:The driver sets the image size to the closest possible values 304 × 224,
	Documentation/userspace-api/media/v4l/crop.rst:is 608 × 224 (224 × 2:1 would exceed the limit 400). The offset 0, 0 is
	Documentation/userspace-api/media/v4l/crop.rst:rectangle of 608 × 456 pixels. The present scaling factors limit
	Documentation/userspace-api/media/v4l/crop.rst:cropping to 640 × 384, so the driver returns the cropping size 608 × 384
	Documentation/userspace-api/media/v4l/crop.rst:and adjusts the image size to closest possible 304 × 192.
	Documentation/userspace-api/media/v4l/diff-v4l.rst:size bitmap of 1024 × 625 bits. Struct :c:type:`v4l2_window`
	Documentation/userspace-api/media/v4l/vidioc-cropcap.rst:       Assuming pixel aspect 1/1 this could be for example a 640 × 480
	Documentation/userspace-api/media/v4l/vidioc-cropcap.rst:       rectangle for NTSC, a 768 × 576 rectangle for PAL and SECAM

it is a way more likely that, if someone wants to grep, they would be 
doing something like this, in order to get video resolutions:

	$ git grep -E "\b[1-9][0-9]+\s*x\s*[0-9]+\b" Documentation/
	Documentation/ABI/obsolete/sysfs-driver-hid-roccat-koneplus:Description:        When read the mouse returns a 30x30 pixel image of the
	Documentation/ABI/obsolete/sysfs-driver-hid-roccat-konepure:Description:        When read the mouse returns a 30x30 pixel image of the
	Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_24x7:               Provides access to the binary "24x7 catalog" provided by the
	Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_24x7:               https://raw.githubusercontent.com/jmesmon/catalog-24x7/master/hv-24x7-	catalog.h
	Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_24x7:               Exposes the "version" field of the 24x7 catalog. This is also
	Documentation/ABI/testing/sysfs-bus-event_source-devices-hv_24x7:               HCALLs to retrieve hv-24x7 pmu event counter data.
	Documentation/ABI/testing/sysfs-bus-vfio-mdev:          "2 heads, 512M FB, 2560x1600 maximum resolution"
	Documentation/ABI/testing/sysfs-driver-wacom:           of the device. The image is a 64x32 pixel 4-bit gray image. The
	Documentation/ABI/testing/sysfs-driver-wacom:           1024 byte binary is split up into 16x 64 byte chunks. Each 64
	Documentation/ABI/testing/sysfs-driver-wacom:           image has to contain 256 bytes (64x32 px 1 bit colour).
	Documentation/admin-guide/edid.rst:commonly used screen resolutions (800x600, 1024x768, 1280x1024, 1600x1200,
	Documentation/admin-guide/edid.rst:1680x1050, 1920x1080) as binary blobs, but the kernel source tree does
	Documentation/admin-guide/edid.rst:If you want to create your own EDID file, copy the file 1024x768.S,
	Documentation/admin-guide/kernel-parameters.txt:                        edid/1024x768.bin, edid/1280x1024.bin,
	Documentation/admin-guide/kernel-parameters.txt:                        edid/1680x1050.bin, or edid/1920x1080.bin is given
	Documentation/admin-guide/kernel-parameters.txt:                        2 - The VGA Shield is attached (1024x768)
	Documentation/admin-guide/media/dvb_intro.rst:signal encoded at a resolution of 768x576 24-bit color pixels over 25
	Documentation/admin-guide/media/imx.rst:1280x960 input frame to 640x480, and then /2 downscale in both
	Documentation/admin-guide/media/imx.rst:dimensions to 320x240 (assumes ipu1_csi0 is linked to ipu1_csi0_mux):
	Documentation/admin-guide/media/imx.rst:   media-ctl -V "'ipu1_csi0_mux':2[fmt:UYVY2X8/1280x960]"

which won't get the above, due to the usage of the UTF-8 alternative.

In any case, replacing all the above by 'x' seems to be the right thing,
at least on my eyes.

> If there are em dashes lying around that semantically _should_ be
>  hyphen-minus (one of your patches I've seen, for instance, fixes an
>  *en* dash moonlighting as the option character in an `ethtool`
>  command line), then sure, convert them.
> But any time someone is using a Unicode character to *express
>  semantics*, even if you happen to think the semantic distinction
>  involved is a pedantic or unimportant one, I think you need an
>  explicit grep case to justify ASCIIfying it.

Yeah, in the case of hyphen/dash it seems to make sense to double check
it.

Thanks,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Edward Cree]

On 10/05/2021 14:38, Mauro Carvalho Chehab wrote:
> Em Mon, 10 May 2021 14:16:16 +0100
> Edward Cree <ecree.xilinx@gmail.com> escreveu:
>> But what kinds of things with × or — in are going to be grept for?
> 
> Actually, on almost all places, those aren't used inside math formulae, but
> instead, they describe video some resolutions:
Ehh, those are also proper uses of ×.  It's still a multiplication,
 after all.

> it is a way more likely that, if someone wants to grep, they would be 
> doing something like this, in order to get video resolutions:
Why would someone be grepping for "all video resolutions mentioned in
 the documentation"?  That seems contrived to me.

-ed

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Matthew Wilcox]

On Mon, May 10, 2021 at 02:16:16PM +0100, Edward Cree wrote:
> On 10/05/2021 12:55, Mauro Carvalho Chehab wrote:
> > The main point on this series is to replace just the occurrences
> > where ASCII represents the symbol equally well
> 
> > 	- U+2014 ('—'): EM DASH
> Em dash is not the same thing as hyphen-minus, and the latter does not
>  serve 'equally well'.  People use em dashes because — even in
>  monospace fonts — they make text easier to read and comprehend, when
>  used correctly.
> I accept that some of the other distinctions — like en dashes — are
>  needlessly pedantic (though I don't doubt there is someone out there
>  who will gladly defend them with the same fervour with which I argue
>  for the em dash) and I wouldn't take the trouble to use them myself;
>  but I think there is a reasonable assumption that when someone goes
>  to the effort of using a Unicode punctuation mark that is semantic
>  (rather than merely typographical), they probably had a reason for
>  doing so.

I think you're overestimating the amount of care and typographical
knowledge that your average kernel developer has.  Most of these
UTF-8 characters come from latex conversions and really aren't
necessary (and are being used incorrectly).

You seem quite knowedgeable about the various differences.  Perhaps
you'd be willing to write a document for Documentation/doc-guide/
that provides guidance for when to use which kinds of horizontal
line?  https://www.punctuationmatters.com/hyphen-dash-n-dash-and-m-dash/
talks about it in the context of publications, but I think we need
something more suited to our needs for kernel documentation.

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Edward Cree]

On 10/05/2021 14:59, Matthew Wilcox wrote:
> Most of these
> UTF-8 characters come from latex conversions and really aren't
> necessary (and are being used incorrectly).
I fully agree with fixing those.
The cover-letter, however, gave the impression that that was not the
 main purpose of this series; just, perhaps, a happy side-effect.

> You seem quite knowedgeable about the various differences.  Perhaps
> you'd be willing to write a document for Documentation/doc-guide/
> that provides guidance for when to use which kinds of horizontal
> line?I have Opinions about the proper usage of punctuation, but I also know
 that other people have differing opinions.  For instance, I place
 spaces around an em dash, which is nonstandard according to most
 style guides.  Really this is an individual enough thing that I'm not
 sure we could have a "kernel style guide" that would be more useful
 than general-purpose guidance like the page you linked.
Moreover, such a guide could make non-native speakers needlessly self-
 conscious about their writing and discourage them from contributing
 documentation at all.  I'm not advocating here for trying to push
 kernel developers towards an eats-shoots-and-leaves level of
 linguistic pedantry; rather, I merely think that existing correct
 usages should be left intact (and therefore, excising incorrect usage
 should only be attempted by someone with both the expertise and time
 to check each case).

But if you really want such a doc I wouldn't mind contributing to it.

-ed

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 15:33:47 +0100
Edward Cree <ecree.xilinx@gmail.com> escreveu:

> On 10/05/2021 14:59, Matthew Wilcox wrote:
> > Most of these
> > UTF-8 characters come from latex conversions and really aren't
> > necessary (and are being used incorrectly).  
> I fully agree with fixing those.
> The cover-letter, however, gave the impression that that was not the
>  main purpose of this series; just, perhaps, a happy side-effect.

Sorry for the mess. The main reason why I wrote this series is because
there are lots of UTF-8 left-over chars from the ReST conversion.
See:
  - https://lore.kernel.org/linux-doc/20210507100435.3095f924@coco.lan/

A large set of the UTF-8 letf-over chars were due to my conversion work,
so I feel personally responsible to fix those ;-)

Yet, this series has two positive side effects:

 - it helps people needing to touch the documents using non-utf8 locales[1];
 - it makes easier to grep for a text;

[1] There are still some widely used distros nowadays (LTS ones?) that
    don't set UTF-8 as default. Last time I installed a Debian machine
    I had to explicitly set UTF-8 charset after install as the default
    were using ASCII encoding (can't remember if it was Debian 10 or an
    older version).

Unintentionally, I ended by giving emphasis to the non-utf8 instead of
giving emphasis to the conversion left-overs.

FYI, this patch series originated from a discussion at linux-doc,
reporting that Sphinx breaks when LANG is not set to utf-8[2]. That's
why I probably ended giving the wrong emphasis at the cover letter.

[2] See https://lore.kernel.org/linux-doc/20210506103913.GE6564@kitsune.suse.cz/
    for the original report. I strongly suspect that the VM set by Michal 
    to build the docs was using a distro that doesn't set UTF-8 as default.

    PS.: 
      I intend to prepare afterwards a separate fix to avoid Sphinx
      logger to crash during Kernel doc builds when the locale charset
      is not UTF-8, but I'm not too fluent in python. So, I need some
      time to check if are there a way to just avoid python log crashes
      without touching Sphinx code and without needing to trick it to 
      think that the machine's locale is UTF-8.

See: while there was just a single document originally stored at the
Kernel tree as a LaTeX document during the time we did the conversion
(cdrom-standard.tex), there are several other documents stored as 
text that seemed to be generated by some tool like LaTeX, whose the
original version were not preserved. 

Also, there were other documents using different markdown dialects 
that were converted via pandoc (and/or other similar tools). That's 
not to mention the ones that were converted from DocBook. Such
tools tend to use some logic to use "neat" versions of some ASCII
characters, like what this tool does:

	https://daringfireball.net/projects/smartypants/

(Sphinx itself seemed to use this tool on its early versions)

All tool-converted documents can carry UTF-8 on unexpected places. See,
on this series, a large amount of patches deal with U+A0 (NO-BREAK SPACE)
chars. I can't see why someone writing a plain text document (or a ReST
one) would type a NO-BREAK SPACE instead of a normal white space.

The same applies, up to some sort, to curly commas: usually people just 
write ASCII "commas" on their documents, and use some tool like LaTeX
or a text editor like libreoffice in order to convert them into
 “utf-8 curly commas”[3].

[3] Sphinx will do such things at the produced output, doing something 
    similar to what smartypants does, nowadays using this:

	https://docutils.sourceforge.io/docs/user/smartquotes.html

    E. g.:
      - Straight quotes (" and ') turned into "curly" quote characters;
      - dashes (-- and ---) turned into en- and em-dash entities;
      - three consecutive dots (... or . . .) turned into an ellipsis char.

> > You seem quite knowedgeable about the various differences.  Perhaps
> > you'd be willing to write a document for Documentation/doc-guide/
> > that provides guidance for when to use which kinds of horizontal
> > line?
> I have Opinions about the proper usage of punctuation, but I also know  
>  that other people have differing opinions.  For instance, I place
>  spaces around an em dash, which is nonstandard according to most
>  style guides.  Really this is an individual enough thing that I'm not
>  sure we could have a "kernel style guide" that would be more useful
>  than general-purpose guidance like the page you linked.

> Moreover, such a guide could make non-native speakers needlessly self-
>  conscious about their writing and discourage them from contributing
>  documentation at all.

I don't think so. In a matter of fact, as a non-native speaker, I guess
this can actually help people willing to write documents.

>  I'm not advocating here for trying to push
>  kernel developers towards an eats-shoots-and-leaves level of
>  linguistic pedantry; rather, I merely think that existing correct
>  usages should be left intact (and therefore, excising incorrect usage
>  should only be attempted by someone with both the expertise and time
>  to check each case).
> 
> But if you really want such a doc I wouldn't mind contributing to it.

IMO, a document like that can be helpful. I can help reviewing it.

Thanks,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[David Woodhouse]

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On Tue, 2021-05-11 at 11:00 +0200, Mauro Carvalho Chehab wrote:
> Yet, this series has two positive side effects:
> 
>  - it helps people needing to touch the documents using non-utf8 locales[1];
>  - it makes easier to grep for a text;
> 
> [1] There are still some widely used distros nowadays (LTS ones?) that
>     don't set UTF-8 as default. Last time I installed a Debian machine
>     I had to explicitly set UTF-8 charset after install as the default
>     were using ASCII encoding (can't remember if it was Debian 10 or an
>     older version).

This whole line of thinking is fundamentally wrong.

A given set of characters in a "text file" are encoded with a specific
character set / encoding. To interpret that file and convert the bytes
back to characters, we need to use the *same* charset.

That charset is a property of the text file, and each text file or
piece of text in a system (like this email, which will contain a
Content-Type: header indicating the charset) might be encoded with a
*different* character set.

In the days before you could connect computers together — or before you
could exchange data between computers in different countries, at least
— perhaps it made sense to store 'text' files without explicitly noting
their encoding. And to interpret them using some kind of "default"
character set.

Those days are long gone. You're trying to work around an egregiously
stupid bug, if you're trying to pander to "default" encodings. There
*is* no default encoding that even makes sense, except perhaps UTF-8.
To *speak* of them as you did shows a misunderstanding of how broken
they are. It's *precisely* that kind of half-baked thinking which
always used to lead to stupid assumptions and double conversions and
Mojibake. Before we just standardised on UTF-8 everywhere and it
stopped mattering so much.

Just don't.

Now, you *can* make this work if you really insist on it, even for
systems with EBCDIC as their default encoding. Just make git do the
"convert to local charset" on checkout, precisely the same way as it
does CRLF for Windows systems. But it's stupid and anachronistic, so I
don't really see the point.


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Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[David Woodhouse]

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On Mon, 2021-05-10 at 13:55 +0200, Mauro Carvalho Chehab wrote:
> This patch series is doing conversion only when using ASCII makes
> more sense than using UTF-8. 
> 
> See, a number of converted documents ended with weird characters
> like ZERO WIDTH NO-BREAK SPACE (U+FEFF) character. This specific
> character doesn't do any good.
> 
> Others use NO-BREAK SPACE (U+A0) instead of 0x20. Harmless, until
> someone tries to use grep[1].

Replacing those makes sense. But replacing emdashes — which are a
distinct character that has no direct replacement in ASCII and which
people do *deliberately* use instead of hyphen-minus — does not.

Perhaps stick to those two, and any cases where an emdash or endash has
been used where U+002D HYPHEN-MINUS *should* have been used.

And please fix your cover letter which made no reference to 'grep', and
only presented a completely bogus argument for the change instead.

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Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Theodore Ts'o]

On Mon, May 10, 2021 at 02:49:44PM +0100, David Woodhouse wrote:
> On Mon, 2021-05-10 at 13:55 +0200, Mauro Carvalho Chehab wrote:
> > This patch series is doing conversion only when using ASCII makes
> > more sense than using UTF-8. 
> > 
> > See, a number of converted documents ended with weird characters
> > like ZERO WIDTH NO-BREAK SPACE (U+FEFF) character. This specific
> > character doesn't do any good.
> > 
> > Others use NO-BREAK SPACE (U+A0) instead of 0x20. Harmless, until
> > someone tries to use grep[1].
> 
> Replacing those makes sense. But replacing emdashes — which are a
> distinct character that has no direct replacement in ASCII and which
> people do *deliberately* use instead of hyphen-minus — does not.

I regularly use --- for em-dashes and -- for en-dashes.  Markdown will
automatically translate 3 ASCII hypens to em-dashes, and 2 ASCII
hyphens to en-dashes.  It's much, much easier for me to type 2 or 3
hypens into my text editor of choice than trying to enter the UTF-8
characters.  If we can make sphinx do this translation, maybe that's
the best way of dealing with these two characters?

Cheers,

					- Ted

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 15:22:02 -0400
"Theodore Ts'o" <tytso@mit.edu> escreveu:

> On Mon, May 10, 2021 at 02:49:44PM +0100, David Woodhouse wrote:
> > On Mon, 2021-05-10 at 13:55 +0200, Mauro Carvalho Chehab wrote:  
> > > This patch series is doing conversion only when using ASCII makes
> > > more sense than using UTF-8. 
> > > 
> > > See, a number of converted documents ended with weird characters
> > > like ZERO WIDTH NO-BREAK SPACE (U+FEFF) character. This specific
> > > character doesn't do any good.
> > > 
> > > Others use NO-BREAK SPACE (U+A0) instead of 0x20. Harmless, until
> > > someone tries to use grep[1].  
> > 
> > Replacing those makes sense. But replacing emdashes — which are a
> > distinct character that has no direct replacement in ASCII and which
> > people do *deliberately* use instead of hyphen-minus — does not.  
> 
> I regularly use --- for em-dashes and -- for en-dashes.  Markdown will
> automatically translate 3 ASCII hypens to em-dashes, and 2 ASCII
> hyphens to en-dashes.  It's much, much easier for me to type 2 or 3
> hypens into my text editor of choice than trying to enter the UTF-8
> characters. 

Yeah, typing those UTF-8 chars are a lot harder than typing -- and ---
on several text editors ;-)

Here, I only type UTF-8 chars for accents (my US-layout keyboards are 
all set to US international, so typing those are easy).

> If we can make sphinx do this translation, maybe that's
> the best way of dealing with these two characters?

Sphinx already does that by default[1], using smartquotes:

	https://docutils.sourceforge.io/docs/user/smartquotes.html

Those are the conversions that are done there:

      - Straight quotes (" and ') turned into "curly" quote characters;
      - dashes (-- and ---) turned into en- and em-dash entities;
      - three consecutive dots (... or . . .) turned into an ellipsis char.

So, we can simply use single/double commas, hyphens and dots for
curly commas and ellipses.

[1] There's a way to disable it at conf.py, but at the Kernel this is
    kept on its default: to automatically do such conversions. 

Thanks,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Mauro Carvalho Chehab]

Em Mon, 10 May 2021 14:49:44 +0100
David Woodhouse <dwmw2@infradead.org> escreveu:

> On Mon, 2021-05-10 at 13:55 +0200, Mauro Carvalho Chehab wrote:
> > This patch series is doing conversion only when using ASCII makes
> > more sense than using UTF-8. 
> > 
> > See, a number of converted documents ended with weird characters
> > like ZERO WIDTH NO-BREAK SPACE (U+FEFF) character. This specific
> > character doesn't do any good.
> > 
> > Others use NO-BREAK SPACE (U+A0) instead of 0x20. Harmless, until
> > someone tries to use grep[1].  
> 
> Replacing those makes sense. But replacing emdashes — which are a
> distinct character that has no direct replacement in ASCII and which
> people do *deliberately* use instead of hyphen-minus — does not.
> 
> Perhaps stick to those two, and any cases where an emdash or endash has
> been used where U+002D HYPHEN-MINUS *should* have been used.

Ok. I'll rework the series excluding EM/EN DASH chars from it.
I'll then apply manually the changes for EM/EN DASH chars 
(probably on a separate series) where it seems to fit. That should
make easier to discuss such replacements.

> And please fix your cover letter which made no reference to 'grep', and
> only presented a completely bogus argument for the change instead.

OK!

Regards,
Mauro

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Ben Boeckel]

On Mon, May 10, 2021 at 13:55:18 +0200, Mauro Carvalho Chehab wrote:
>     $ git grep "CPU 0 has been" Documentation/RCU/
>       Documentation/RCU/Design/Data-Structures/Data-Structures.rst:| #. CPU 0 has been in dyntick-idle mode for quite some time. When it   |
>       Documentation/RCU/Design/Data-Structures/Data-Structures.rst:|    notices that CPU 0 has been in dyntick idle mode, which qualifies  |

The kernel documentation uses hard line wraps, so such a naive grep is
going to always fail unless such line wraps are taken into account. Not
saying this isn't an improvement in and of itself, but smarter searching
strategies are likely needed anyways.

--Ben

Re: [PATCH 00/53] Get rid of UTF-8 chars that can be mapped as ASCII

[Adam Borowski]

On Mon, May 10, 2021 at 12:26:12PM +0200, Mauro Carvalho Chehab wrote:
> There are several UTF-8 characters at the Kernel's documentation.
[...]
> Other UTF-8 characters were added along the time, but they're easily
> replaceable by ASCII chars.
> 
> As Linux developers are all around the globe, and not everybody has UTF-8
> as their default charset

I'm not aware of a distribution that still allows selecting a non-UTF-8
charset in a normal flow in their installer.  And if they haven't purged
support for ancient encodings, that support is thoroughly bitrotten.
Thus, I disagree that this is a legitimate concern.

What _could_ be a legitimate reason is that someone is on a _terminal_
that can't display a wide enough set of glyphs.  Such terminals are:
 • Linux console (because of vgacon limitations; patchsets to improve
   other cons haven't been mainlined)
 • some Windows terminals (putty, old Windows console) that can't borrow
   glyphs from other fonts like fontconfig can

For the former, it's whatever your distribution ships in
/usr/share/consolefonts/ or an equivalent, which is based on historic
ISO-8859 and VT100 traditions.

For the latter, the near-guaranteed character set is WGL4.


Thus, at least two of your choices seem to disagree with the above:
[dropped]
> 	0xd7   => 'x',		# MULTIPLICATION SIGN
[retained]
> 	- U+2b0d ('⬍'): UP DOWN BLACK ARROW

× is present in ISO-8859, V100, WGL4; I've found no font in
/usr/share/consolefonts/ on my Debian unstable box that lacks this
character.

⬍ is not found in any of the above.  You might want to at least
convert it to ↕ which is at least present in WGL4, and thus likely
to be supported in fonts heeding Windows/Mac/OpenType recommendations.
That still won't make it work on VT.


Meow!
-- 
⢀⣴⠾⠻⢶⣦⠀ .--[ Makefile ]
⣾⠁⢠⠒⠀⣿⡁ # beware of races
⢿⡄⠘⠷⠚⠋⠀ all: pillage burn
⠈⠳⣄⠀⠀⠀⠀ `----