Merge tag 'docs-5.18' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "It has been a moderately busy cycle for documentation; some of the
  highlights are:

   - Numerous PDF-generation improvements

   - Kees's new document with guidelines for researchers studying the
     development community.

   - The ongoing stream of Chinese translations

   - Thorsten's new document on regression handling

   - A major reworking of the internal documentation for the kernel-doc
     script.

  Plus the usual stream of typo fixes and such"

* tag 'docs-5.18' of git://git.lwn.net/linux: (80 commits)
  docs/kernel-parameters: update description of mem=
  docs/zh_CN: Add sched-nice-design Chinese translation
  docs: scheduler: Convert schedutil.txt to ReST
  Docs: ktap: add code-block type
  docs: serial: fix a reference file name in driver.rst
  docs: UML: Mention telnetd for port channel
  docs/zh_CN: add damon reclaim translation
  docs/zh_CN: add damon usage translation
  docs/zh_CN: add admin-guide damon start translation
  docs/zh_CN: add admin-guide damon index translation
  docs/zh_CN: Refactoring the admin-guide directory index
  zh_CN: Add translation for admin-guide/mm/index.rst
  zh_CN: Add translations for admin-guide/mm/ksm.rst
  Add Chinese translation for vm/ksm.rst
  docs/zh_CN: Add sched-stats Chinese translation
  docs/zh_CN: add devicetree of_unittest translation
  docs/zh_CN: add devicetree usage-model translation
  docs/zh_CN: add devicetree index translation
  Documentation: describe how to apply incremental stable patches
  docs/zh_CN: add peci subsystem translation
  ...

Author: torvalds

Documentation/Makefile

@@ -26,7 +26,7 @@ SPHINX_CONF   = conf.py
 PAPER         =
 BUILDDIR      = $(obj)/output
 PDFLATEX      = xelatex
-LATEXOPTS     = -interaction=batchmode
+LATEXOPTS     = -interaction=batchmode -no-shell-escape
 
 ifeq ($(KBUILD_VERBOSE),0)
 SPHINXOPTS    += "-q"

Documentation/admin-guide/blockdev/zram.rst

@@ -315,8 +315,8 @@ To use the feature, admin should set up backing device via::
 
 	echo /dev/sda5 > /sys/block/zramX/backing_dev
 
-before disksize setting. It supports only partition at this moment.
-If admin wants to use incompressible page writeback, they could do via::
+before disksize setting. It supports only partitions at this moment.
+If admin wants to use incompressible page writeback, they could do it via::
 
 	echo huge > /sys/block/zramX/writeback
 
@@ -341,9 +341,9 @@ Admin can request writeback of those idle pages at right timing via::
 
 	echo idle > /sys/block/zramX/writeback
 
-With the command, zram writeback idle pages from memory to the storage.
+With the command, zram will writeback idle pages from memory to the storage.
 
-If admin want to write a specific page in zram device to backing device,
+If an admin wants to write a specific page in zram device to the backing device,
 they could write a page index into the interface.
 
 	echo "page_index=1251" > /sys/block/zramX/writeback
@@ -354,7 +354,7 @@ to guarantee storage health for entire product life.
 
 To overcome the concern, zram supports "writeback_limit" feature.
 The "writeback_limit_enable"'s default value is 0 so that it doesn't limit
-any writeback. IOW, if admin wants to apply writeback budget, he should
+any writeback. IOW, if admin wants to apply writeback budget, they should
 enable writeback_limit_enable via::
 
 	$ echo 1 > /sys/block/zramX/writeback_limit_enable
@@ -365,7 +365,7 @@ until admin sets the budget via /sys/block/zramX/writeback_limit.
 (If admin doesn't enable writeback_limit_enable, writeback_limit's value
 assigned via /sys/block/zramX/writeback_limit is meaningless.)
 
-If admin want to limit writeback as per-day 400M, he could do it
+If admin wants to limit writeback as per-day 400M, they could do it
 like below::
 
 	$ MB_SHIFT=20
@@ -375,16 +375,16 @@ like below::
 	$ echo 1 > /sys/block/zram0/writeback_limit_enable
 
 If admins want to allow further write again once the budget is exhausted,
-he could do it like below::
+they could do it like below::
 
 	$ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
 		/sys/block/zram0/writeback_limit
 
-If admin wants to see remaining writeback budget since last set::
+If an admin wants to see the remaining writeback budget since last set::
 
 	$ cat /sys/block/zramX/writeback_limit
 
-If admin want to disable writeback limit, he could do::
+If an admin wants to disable writeback limit, they could do::
 
 	$ echo 0 > /sys/block/zramX/writeback_limit_enable
 
@@ -393,7 +393,7 @@ system reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of
 writeback happened until you reset the zram to allocate extra writeback
 budget in next setting is user's job.
 
-If admin wants to measure writeback count in a certain period, he could
+If admin wants to measure writeback count in a certain period, they could
 know it via /sys/block/zram0/bd_stat's 3rd column.
 
 memory tracking

Documentation/admin-guide/index.rst

@@ -35,6 +35,7 @@ problems and bugs in particular.
    :maxdepth: 1
 
    reporting-issues
+   reporting-regressions
    security-bugs
    bug-hunting
    bug-bisect

Documentation/admin-guide/iostats.rst

@@ -76,7 +76,7 @@ Field  3 -- # of sectors read (unsigned long)
 
 Field  4 -- # of milliseconds spent reading (unsigned int)
     This is the total number of milliseconds spent by all reads (as
-    measured from __make_request() to end_that_request_last()).
+    measured from blk_mq_alloc_request() to __blk_mq_end_request()).
 
 Field  5 -- # of writes completed (unsigned long)
     This is the total number of writes completed successfully.
@@ -89,7 +89,7 @@ Field  7 -- # of sectors written (unsigned long)
 
 Field  8 -- # of milliseconds spent writing (unsigned int)
     This is the total number of milliseconds spent by all writes (as
-    measured from __make_request() to end_that_request_last()).
+    measured from blk_mq_alloc_request() to __blk_mq_end_request()).
 
 Field  9 -- # of I/Os currently in progress (unsigned int)
     The only field that should go to zero. Incremented as requests are
@@ -120,7 +120,7 @@ Field 14 -- # of sectors discarded (unsigned long)
 
 Field 15 -- # of milliseconds spent discarding (unsigned int)
     This is the total number of milliseconds spent by all discards (as
-    measured from __make_request() to end_that_request_last()).
+    measured from blk_mq_alloc_request() to __blk_mq_end_request()).
 
 Field 16 -- # of flush requests completed
     This is the total number of flush requests completed successfully.

Documentation/admin-guide/kernel-parameters.txt

@@ -2827,13 +2827,23 @@
 
 			For details see: Documentation/admin-guide/hw-vuln/mds.rst
 
+	mem=nn[KMG]	[HEXAGON] Set the memory size.
+			Must be specified, otherwise memory size will be 0.
+
 	mem=nn[KMG]	[KNL,BOOT] Force usage of a specific amount of memory
 			Amount of memory to be used in cases as follows:
 
 			1 for test;
 			2 when the kernel is not able to see the whole system memory;
 			3 memory that lies after 'mem=' boundary is excluded from
 			 the hypervisor, then assigned to KVM guests.
+			4 to limit the memory available for kdump kernel.
+
+			[ARC,MICROBLAZE] - the limit applies only to low memory,
+			high memory is not affected.
+
+			[ARM64] - only limits memory covered by the linear
+			mapping. The NOMAP regions are not affected.
 
 			[X86] Work as limiting max address. Use together
 			with memmap= to avoid physical address space collisions.
@@ -2844,6 +2854,14 @@
 			in above case 3, memory may need be hot added after boot
 			if system memory of hypervisor is not sufficient.
 
+	mem=nn[KMG]@ss[KMG]
+			[ARM,MIPS] - override the memory layout reported by
+			firmware.
+			Define a memory region of size nn[KMG] starting at
+			ss[KMG].
+			Multiple different regions can be specified with
+			multiple mem= parameters on the command line.
+
 	mem=nopentium	[BUGS=X86-32] Disable usage of 4MB pages for kernel
 			memory.
 

Documentation/admin-guide/perf/index.rst

@@ -8,6 +8,7 @@ Performance monitor support
    :maxdepth: 1
 
    hisi-pmu
+   hisi-pcie-pmu
    imx-ddr
    qcom_l2_pmu
    qcom_l3_pmu

Documentation/admin-guide/reporting-issues.rst

@@ -1,14 +1,5 @@
 .. SPDX-License-Identifier: (GPL-2.0+ OR CC-BY-4.0)
-..
-   If you want to distribute this text under CC-BY-4.0 only, please use 'The
-   Linux kernel developers' for author attribution and link this as source:
-   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/Documentation/admin-guide/reporting-issues.rst
-..
-   Note: Only the content of this RST file as found in the Linux kernel sources
-   is available under CC-BY-4.0, as versions of this text that were processed
-   (for example by the kernel's build system) might contain content taken from
-   files which use a more restrictive license.
-
+.. See the bottom of this file for additional redistribution information.
 
 Reporting issues
 ++++++++++++++++
@@ -395,22 +386,16 @@ fixed as soon as possible, hence there are 'issues of high priority' that get
 handled slightly differently in the reporting process. Three type of cases
 qualify: regressions, security issues, and really severe problems.
 
-You deal with a 'regression' if something that worked with an older version of
-the Linux kernel does not work with a newer one or somehow works worse with it.
-It thus is a regression when a WiFi driver that did a fine job with Linux 5.7
-somehow misbehaves with 5.8 or doesn't work at all. It's also a regression if
-an application shows erratic behavior with a newer kernel, which might happen
-due to incompatible changes in the interface between the kernel and the
-userland (like procfs and sysfs). Significantly reduced performance or
-increased power consumption also qualify as regression. But keep in mind: the
-new kernel needs to be built with a configuration that is similar to the one
-from the old kernel (see below how to achieve that). That's because the kernel
-developers sometimes can not avoid incompatibilities when implementing new
-features; but to avoid regressions such features have to be enabled explicitly
-during build time configuration.
+You deal with a regression if some application or practical use case running
+fine with one Linux kernel works worse or not at all with a newer version
+compiled using a similar configuration. The document
+Documentation/admin-guide/reporting-regressions.rst explains this in more
+detail. It also provides a good deal of other information about regressions you
+might want to be aware of; it for example explains how to add your issue to the
+list of tracked regressions, to ensure it won't fall through the cracks.
 
 What qualifies as security issue is left to your judgment. Consider reading
-'Documentation/admin-guide/security-bugs.rst' before proceeding, as it
+Documentation/admin-guide/security-bugs.rst before proceeding, as it
 provides additional details how to best handle security issues.
 
 An issue is a 'really severe problem' when something totally unacceptably bad
@@ -517,7 +502,7 @@ line starting with 'CPU:'. It should end with 'Not tainted' if the kernel was
 not tainted when it noticed the problem; it was tainted if you see 'Tainted:'
 followed by a few spaces and some letters.
 
-If your kernel is tainted, study 'Documentation/admin-guide/tainted-kernels.rst'
+If your kernel is tainted, study Documentation/admin-guide/tainted-kernels.rst
 to find out why. Try to eliminate the reason. Often it's caused by one these
 three things:
 
@@ -1043,7 +1028,7 @@ down the culprit, as maintainers often won't have the time or setup at hand to
 reproduce it themselves.
 
 To find the change there is a process called 'bisection' which the document
-'Documentation/admin-guide/bug-bisect.rst' describes in detail. That process
+Documentation/admin-guide/bug-bisect.rst describes in detail. That process
 will often require you to build about ten to twenty kernel images, trying to
 reproduce the issue with each of them before building the next. Yes, that takes
 some time, but don't worry, it works a lot quicker than most people assume.
@@ -1073,10 +1058,11 @@ When dealing with regressions make sure the issue you face is really caused by
 the kernel and not by something else, as outlined above already.
 
 In the whole process keep in mind: an issue only qualifies as regression if the
-older and the newer kernel got built with a similar configuration. The best way
-to archive this: copy the configuration file (``.config``) from the old working
-kernel freshly to each newer kernel version you try. Afterwards run ``make
-olddefconfig`` to adjust it for the needs of the new version.
+older and the newer kernel got built with a similar configuration. This can be
+achieved by using ``make olddefconfig``, as explained in more detail by
+Documentation/admin-guide/reporting-regressions.rst; that document also
+provides a good deal of other information about regressions you might want to be
+aware of.
 
 
 Write and send the report
@@ -1283,7 +1269,7 @@ them when sending the report by mail. If you filed it in a bug tracker, forward
 the report's text to these addresses; but on top of it put a small note where
 you mention that you filed it with a link to the ticket.
 
-See 'Documentation/admin-guide/security-bugs.rst' for more information.
+See Documentation/admin-guide/security-bugs.rst for more information.
 
 
 Duties after the report went out
@@ -1571,7 +1557,7 @@ Once your report is out your might get asked to do a proper one, as it allows to
 pinpoint the exact change that causes the issue (which then can easily get
 reverted to fix the issue quickly). Hence consider to do a proper bisection
 right away if time permits. See the section 'Special care for regressions' and
-the document 'Documentation/admin-guide/bug-bisect.rst' for details how to
+the document Documentation/admin-guide/bug-bisect.rst for details how to
 perform one. In case of a successful bisection add the author of the culprit to
 the recipients; also CC everyone in the signed-off-by chain, which you find at
 the end of its commit message.
@@ -1594,7 +1580,7 @@ Some fixes are too complex
 Even small and seemingly obvious code-changes sometimes introduce new and
 totally unexpected problems. The maintainers of the stable and longterm kernels
 are very aware of that and thus only apply changes to these kernels that are
-within rules outlined in 'Documentation/process/stable-kernel-rules.rst'.
+within rules outlined in Documentation/process/stable-kernel-rules.rst.
 
 Complex or risky changes for example do not qualify and thus only get applied
 to mainline. Other fixes are easy to get backported to the newest stable and
@@ -1756,10 +1742,23 @@ art will lay some groundwork to improve the situation over time.
 
 
 ..
-   This text is maintained by Thorsten Leemhuis <linux@leemhuis.info>. If you
-   spot a typo or small mistake, feel free to let him know directly and he'll
-   fix it. You are free to do the same in a mostly informal way if you want
-   to contribute changes to the text, but for copyright reasons please CC
+   end-of-content
+..
+   This document is maintained by Thorsten Leemhuis <linux@leemhuis.info>. If
+   you spot a typo or small mistake, feel free to let him know directly and
+   he'll fix it. You are free to do the same in a mostly informal way if you
+   want to contribute changes to the text, but for copyright reasons please CC
    linux-doc@vger.kernel.org and "sign-off" your contribution as
    Documentation/process/submitting-patches.rst outlines in the section "Sign
    your work - the Developer's Certificate of Origin".
+..
+   This text is available under GPL-2.0+ or CC-BY-4.0, as stated at the top
+   of the file. If you want to distribute this text under CC-BY-4.0 only,
+   please use "The Linux kernel developers" for author attribution and link
+   this as source:
+   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/Documentation/admin-guide/reporting-issues.rst
+..
+   Note: Only the content of this RST file as found in the Linux kernel sources
+   is available under CC-BY-4.0, as versions of this text that were processed
+   (for example by the kernel's build system) might contain content taken from
+   files which use a more restrictive license.