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Date:   Mon, 31 May 2021 16:35:30 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Jonathan Corbet <corbet@lwn.net>
Cc:     x86-ml <x86@kernel.org>, lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] Documentation/submitting-patches: Document RESEND tag on
 patches
Message-ID: <YLT0MjAIO/8u4cjY@zn.tnic>
References: <20201217183756.GE23634@zn.tnic>
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Wow, time flies. :-\

A month and a half later, Jon, how about it?

Thx.

On Thu, Apr 15, 2021 at 08:05:05AM +0200, Borislav Petkov wrote:
> On Tue, Apr 13, 2021 at 03:02:21PM -0600, Jonathan Corbet wrote:
> > For future installments, could you send them in their own thread as an
> > ordinary patch so I don't need to edit in the changelog after applying
> > them?
> 
> Ok, sure but I might not need to anymore because, AFAICT, what is left
> is really tip-tree specific and that can finally be the tip-tree doc
> file.
> 
> I'm pasting the whole thing below, if you think something's still
> generic enough, lemme know and I'll carve it out.
> 
> Thx.
> 
> ---
> .. SPDX-License-Identifier: GPL-2.0
> 
> The tip tree handbook
> =====================
> 
> What is the tip tree?
> ---------------------
> 
> The tip tree is a collection of several subsystems and areas of
> development. The tip tree is both a direct development tree and a
> aggregation tree for several sub-maintainer trees. The tip tree gitweb URL
> is: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
> 
> The tip tree contains the following subsystems:
> 
>    - **x86 architecture**
> 
>      The x86 architecture development takes place in the tip tree except
>      for the x86 KVM and XEN specific parts which are maintained in the
>      corresponding subsystems and routed directly to mainline from
>      there. It's still good practice to Cc the x86 maintainers on
>      x86-specific KVM and XEN patches.
> 
>      Some x86 subsystems have their own maintainers in addition to the
>      overall x86 maintainers.  Please Cc the overall x86 maintainers on
>      patches touching files in arch/x86 even when they are not called out
>      by the MAINTAINER file.
> 
>      Note, that ``x86@kernel.org`` is not a mailing list. It is merely a
>      mail alias which distributes mails to the x86 top-level maintainer
>      team. Please always Cc the Linux Kernel mailing list (LKML)
>      ``linux-kernel@vger.kernel.org``, otherwise your mail ends up only in
>      the private inboxes of the maintainers.
> 
>    - **Scheduler**
> 
>      Scheduler development takes place in the -tip tree, in the
>      sched/core branch - with occasional sub-topic trees for
>      work-in-progress patch-sets.
> 
>    - **Locking and atomics**
> 
>      Locking development (including atomics and other synchronization
>      primitives that are connected to locking) takes place in the -tip
>      tree, in the locking/core branch - with occasional sub-topic trees
>      for work-in-progress patch-sets.
> 
>    - **Generic interrupt subsystem and interrupt chip drivers**:
> 
>      - interrupt core development happens in the irq/core branch
> 
>      - interrupt chip driver development also happens in the irq/core
>        branch, but the patches are usually applied in a separate maintainer
>        tree and then aggregated into irq/core
> 
>    - **Time, timers, timekeeping, NOHZ and related chip drivers**:
> 
>      - timekeeping, clocksource core, NTP and alarmtimer development
>        happens in the timers/core branch, but patches are usually applied in
>        a separate maintainer tree and then aggregated into timers/core
> 
>      - clocksource/event driver development happens in the timers/core
>        branch, but patches are mostly applied in a separate maintainer tree
>        and then aggregated into timers/core
> 
>    - **Performance counters core, architecture support and tooling**:
> 
>      - perf core and architecture support development happens in the
>        perf/core branch
> 
>      - perf tooling development happens in the perf tools maintainer
>        tree and is aggregated into the tip tree.
> 
>    - **CPU hotplug core**
> 
>    - **RAS core**
> 
>    - **EFI core**
> 
>      EFI development in the efi git tree. The collected patches are
>      aggregated in the tip efi/core branch.
> 
>    - **RCU**
> 
>      RCU development happens in the linux-rcu tree. The resulting changes
>      are aggregated into the tip core/rcu branch.
> 
>    - **Various core code components**:
> 
>        - debugobjects
> 
>        - objtool
> 
>        - random bits and pieces
> 
> 
> Patch submission notes
> ----------------------
> 
> Selecting the tree/branch
> ^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> In general, development against the head of the tip tree master branch is
> fine, but for the subsystems which are maintained separately, have their
> own git tree and are only aggregated into the tip tree, development should
> take place against the relevant subsystem tree or branch.
> 
> Bug fixes which target mainline should always be applicable against the
> mainline kernel tree. Potential conflicts against changes which are already
> queued in the tip tree are handled by the maintainers.
> 
> Patch subject
> ^^^^^^^^^^^^^
> 
> The tip tree preferred format for patch subject prefixes is
> 'subsys/component:', e.g. 'x86/apic:', 'x86/mm/fault:', 'sched/fair:',
> 'genirq/core:'. Please do not use file names or complete file paths as
> prefix. 'git log path/to/file' should give you a reasonable hint in most
> cases.
> 
> The condensed patch description in the subject line should start with a
> uppercase letter and should be written in imperative tone.
> 
> 
> Changelog
> ^^^^^^^^^
> 
> The general rules about changelogs in the process documentation, see
> :ref:`Documentation/process/ <submittingpatches>`, apply.
> 
> The tip tree maintainers set value on following these rules, especially on
> the request to write changelogs in imperative mood and not impersonating
> code or the execution of it. This is not just a whim of the
> maintainers. Changelogs written in abstract words are more precise and
> tend to be less confusing than those written in the form of novels.
> 
> It's also useful to structure the changelog into several paragraphs and not
> lump everything together into a single one. A good structure is to explain
> the context, the problem and the solution in separate paragraphs and this
> order.
> 
> Examples for illustration:
> 
>   Example 1::
> 
>     x86/intel_rdt/mbm: Fix MBM overflow handler during hot cpu
> 
>     When a CPU is dying, we cancel the worker and schedule a new worker on a
>     different CPU on the same domain. But if the timer is already about to
>     expire (say 0.99s) then we essentially double the interval.
> 
>     We modify the hot cpu handling to cancel the delayed work on the dying
>     cpu and run the worker immediately on a different cpu in same domain. We
>     donot flush the worker because the MBM overflow worker reschedules the
>     worker on same CPU and scans the domain->cpu_mask to get the domain
>     pointer.
> 
>   Improved version::
> 
>     x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug
> 
>     When a CPU is dying, the overflow worker is canceled and rescheduled on a
>     different CPU in the same domain. But if the timer is already about to
>     expire this essentially doubles the interval which might result in a non
>     detected overflow.
> 
>     Cancel the overflow worker and reschedule it immediately on a different CPU
>     in the same domain. The work could be flushed as well, but that would
>     reschedule it on the same CPU.
> 
>   Example 2::
> 
>     time: POSIX CPU timers: Ensure that variable is initialized
> 
>     If cpu_timer_sample_group returns -EINVAL, it will not have written into
>     *sample. Checking for cpu_timer_sample_group's return value precludes the
>     potential use of an uninitialized value of now in the following block.
>     Given an invalid clock_idx, the previous code could otherwise overwrite
>     *oldval in an undefined manner. This is now prevented. We also exploit
>     short-circuiting of && to sample the timer only if the result will
>     actually be used to update *oldval.
> 
>   Improved version::
> 
>     posix-cpu-timers: Make set_process_cpu_timer() more robust
> 
>     Because the return value of cpu_timer_sample_group() is not checked,
>     compilers and static checkers can legitimately warn about a potential use
>     of the uninitialized variable 'now'. This is not a runtime issue as all
>     call sites hand in valid clock ids.
> 
>     Also cpu_timer_sample_group() is invoked unconditionally even when the
>     result is not used because *oldval is NULL.
> 
>     Make the invocation conditional and check the return value.
> 
>   Example 3::
> 
>     The entity can also be used for other purposes.
> 
>     Let's rename it to be more generic.
> 
>   Improved version::
> 
>     The entity can also be used for other purposes.
> 
>     Rename it to be more generic.
> 
> 
> For complex scenarios, especially race conditions and memory ordering
> issues, it is valuable to depict the scenario with a table which shows
> the parallelism and the temporal order of events. Here is an example::
> 
>     CPU0                            CPU1
>     free_irq(X)                     interrupt X
>                                     spin_lock(desc->lock)
>                                     wake irq thread()
>                                     spin_unlock(desc->lock)
>     spin_lock(desc->lock)
>     remove action()
>     shutdown_irq()
>     release_resources()             thread_handler()
>     spin_unlock(desc->lock)           access released resources.
>                                       ^^^^^^^^^^^^^^^^^^^^^^^^^
>     synchronize_irq()
> 
> Lockdep provides similar useful output to depict a possible deadlock
> scenario::
> 
>     CPU0                                    CPU1
>     rtmutex_lock(&rcu->rt_mutex)
>       spin_lock(&rcu->rt_mutex.wait_lock)
>                                             local_irq_disable()
>                                             spin_lock(&timer->it_lock)
>                                             spin_lock(&rcu->mutex.wait_lock)
>     --> Interrupt
>         spin_lock(&timer->it_lock)
> 
> 
> Function references in changelogs
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> When a function is mentioned in the changelog, either the text body or the
> subject line, please use the format 'function_name()'. Omitting the
> brackets after the function name can be ambiguous::
> 
>   Subject: subsys/component: Make reservation_count static
> 
>   reservation_count is only used in reservation_stats. Make it static.
> 
> The variant with brackets is more precise::
> 
>   Subject: subsys/component: Make reservation_count() static
> 
>   reservation_count() is only called from reservation_stats(). Make it
>   static.
> 
> 
> Backtraces in changelogs
> ^^^^^^^^^^^^^^^^^^^^^^^^
> 
> (XXX: Add link to Documentation/process/submitting-patches.rst's section)
> 
> Ordering of commit tags
> ^^^^^^^^^^^^^^^^^^^^^^^
> 
> To have a uniform view of the commit tags, the tip maintainers use the
> following tag ordering scheme:
> 
>  - Fixes: 12char-SHA1 ("sub/sys: Original subject line")
> 
>    A Fixes tag should be added even for changes which do not need to be
>    backported to stable kernels, i.e. when addressing a recently introduced
>    issue which only affects tip or the current head of mainline. These tags
>    are helpful to identify the original commit and are much more valuable
>    than prominently mentioning the commit which introduced a problem in the
>    text of the changelog itself because they can be automatically
>    extracted.
> 
>    The following example illustrates the difference::
> 
>      Commit
> 
>        abcdef012345678 ("x86/xxx: Replace foo with bar")
> 
>      left an unused instance of variable foo around. Remove it.
> 
>      Signed-off-by: J.Dev <j.dev@mail>
> 
>    Please say instead::
> 
>      The recent replacement of foo with bar left an unused instance of
>      variable foo around. Remove it.
> 
>      Fixes: abcdef012345678 ("x86/xxx: Replace foo with bar")
>      Signed-off-by: J.Dev <j.dev@mail>
> 
>    The latter puts the information about the patch into the focus and
>    amends it with the reference to the commit which introduced the issue
>    rather than putting the focus on the original commit in the first place.
> 
>  - Reported-by: ``Reporter <reporter@mail>``
> 
>  - Originally-by: ``Original author <original-author@mail>``
> 
>  - Suggested-by: ``Suggester <suggester@mail>``
> 
>  - Co-developed-by: ``Co-author <co-author@mail>``
> 
>    Signed-off: ``Co-author <co-author@mail>``
> 
>    Note, that Co-developed-by and Signed-off-by of the co-author(s) must
>    come in pairs.
> 
>  - Signed-off-by: ``Author <author@mail>``
> 
>    The first Signed-off-by (SOB) after the last Co-developed-by/SOB pair is the
>    author SOB, i.e. the person flagged as author by git.
> 
>  - Signed-off-by: ``Patch handler <handler@mail>``
> 
>    SOBs after the author SOB are from people handling and transporting
>    the patch, but were not involved in development. SOB chains should
>    reflect the **real** route a patch took as it was propagated to us,
>    with the first SOB entry signalling primary authorship of a single
>    author. Acks should be given as Acked-by lines and review approvals
>    as Reviewed-by lines.
> 
>    If the handler made modifications to the patch or the changelog, then
>    this should be mentioned **after** the changelog text and **above**
>    all commit tags in the following format::
> 
>      ... changelog text ends.
> 
>      [ handler: Replaced foo by bar and updated changelog ]
> 
>      First-tag: .....
> 
>    Note the two empty new lines which separate the changelog text and the
>    commit tags from that notice.
> 
>    If a patch is sent to the mailing list by a handler then the author has
>    to be noted in the first line of the changelog with::
> 
>      From: Author <author@mail>
> 
>      Changelog text starts here....
> 
>    so the authorship is preserved. The 'From:' line has to be followed
>    by a empty newline. If that 'From:' line is missing, then the patch
>    would be attributed to the person who sent (transported, handled) it.
>    The 'From:' line is automatically removed when the patch is applied
>    and does not show up in the final git changelog. It merely affects
>    the authorship information of the resulting Git commit.
> 
>  - Tested-by: ``Tester <tester@mail>``
> 
>  - Reviewed-by: ``Reviewer <reviewer@mail>``
> 
>  - Acked-by: ``Acker <acker@mail>``
> 
>  - Cc: ``cc-ed-person <person@mail>``
> 
>    If the patch should be backported to stable, then please add a '``Cc:
>    stable@vger.kernel.org``' tag, but do not Cc stable when sending your
>    mail.
> 
>  - Link: ``https://link/to/information``
> 
>    For referring to an email on LKML or other kernel mailing lists,
>    please use the lkml.kernel.org redirector URL::
> 
>      https://lkml.kernel.org/r/email-message@id
> 
>    The kernel.org redirector is considered a stable URL, unlike other email
>    archives.
> 
>    Maintainers will add a Link tag referencing the email of the patch
>    submission when they apply a patch to the tip tree. This tag is useful
>    for later reference and is also used for commit notifications.
> 
> Please do not use combined tags, e.g. ``Reported-and-tested-by``, as
> they just complicate automated extraction of tags.
> 
> 
> Links to documentation
> ^^^^^^^^^^^^^^^^^^^^^^
> 
> Providing links to documentation in the changelog is a great help to later
> debugging and analysis.  Unfortunately, URLs often break very quickly
> because companies restructure their websites frequently.  Non-'volatile'
> exceptions include the Intel SDM and the AMD APM.
> 
> Therefore, for 'volatile' documents, please create an entry in the kernel
> bugzilla https://bugzilla.kernel.org and attach a copy of these documents
> to the bugzilla entry. Finally, provide the URL of the bugzilla entry in
> the changelog.
> 
> 
> Patch version information
> ^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> (XXX: Add link to Documentation/process/submitting-patches.rst's section)
> 
> Patch resend or reminders
> ^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> (XXX: point this to "Don't get discouraged - or impatient" section in
> Documentation/process/submitting-patches.rst)
> 
> 
> Merge window
> ^^^^^^^^^^^^
> 
> Please do not expect large patch series to be handled during the merge
> window or even during the week before.  Such patches should be submitted in
> mergeable state *at* *least* a week before the merge window opens.
> Exceptions are made for bug fixes and *sometimes* for small standalone
> drivers for new hardware or minimally invasive patches for hardware
> enablement.
> 
> During the merge window, the maintainers instead focus on following the
> upstream changes, fixing merge window fallout, collecting bug fixes, and
> allowing themselves a breath. Please respect that.
> 
> The release candidate -rc1 is the starting point for new patches to be
> applied which are targeted for the next merge window.
> 
> 
> Git
> ^^^
> 
> The tip maintainers accept git pull requests from maintainers who provide
> subsystem changes for aggregation in the tip tree.
> 
> Pull requests for new patch submissions are usually not accepted and do not
> replace proper patch submission to the mailing list. The main reason for
> this is that the review workflow is email based.
> 
> If you submit a larger patch series it is helpful to provide a git branch
> in a private repository which allows interested people to easily pull the
> series for testing. The usual way to offer this is a git URL in the cover
> letter of the patch series.
> 
> 
> Coding style notes
> ------------------
> 
> Comment style
> ^^^^^^^^^^^^^
> 
> Sentences in comments start with an uppercase letter.
> 
> Single line comments::
> 
> 	/* This is a single line comment */
> 
> Multi-line comments::
> 
> 	/*
> 	 * This is a properly formatted
> 	 * multi-line comment.
> 	 *
> 	 * Larger multi-line comments should be split into paragraphs.
> 	 */
> 
> No tail comments:
> 
>   Please refrain from using tail comments. Tail comments disturb the
>   reading flow in almost all contexts, but especially in code::
> 
> 	if (somecondition_is_true) /* Don't put a comment here */
> 		dostuff(); /* Neither here */
> 
> 	seed = MAGIC_CONSTANT; /* Nor here */
> 
>   Use freestanding comments instead::
> 
> 	/* This condition is not obvious without a comment */
> 	if (somecondition_is_true) {
> 		/* This really needs to be documented */
> 		dostuff();
> 	}
> 
> 	/* This magic initialization needs a comment. Maybe not? */
> 	seed = MAGIC_CONSTANT;
> 
> Comment the important things:
> 
>   Comments should be added where the operation is not obvious. Documenting
>   the obvious is just a distraction::
> 
> 	/* Decrement refcount and check for zero */
> 	if (refcount_dec_and_test(&p->refcnt)) {
> 		do;
> 		lots;
> 		of;
> 		magic;
> 		things;
> 	}
> 
>   Instead, comments should explain the non-obvious details and document
>   constraints::
> 
> 	if (refcount_dec_and_test(&p->refcnt)) {
> 		/*
> 		 * Really good explanation why the magic things below
> 		 * need to be done, ordering and locking constraints,
> 		 * etc..
> 		 */
> 		do;
> 		lots;
> 		of;
> 		magic;
> 		/* Needs to be the last operation because ... */
> 		things;
> 	}
> 
> Function documentation comments:
> 
>   To document functions and their arguments please use kernel-doc format
>   and not free form comments::
> 
> 	/**
> 	 * magic_function - Do lots of magic stuff
> 	 * @magic:	Pointer to the magic data to operate on
> 	 * @offset:	Offset in the data array of @magic
> 	 *
> 	 * Deep explanation of mysterious things done with @magic along
>          * with documentation of the return values.
> 	 *
> 	 * Note, that the argument descriptors above are arranged
> 	 * in a tabular fashion.
> 	 */
> 
>   This applies especially to globally visible functions and inline
>   functions in public header files. It might be overkill to use kernel-doc
>   format for every (static) function which needs a tiny explanation. The
>   usage of descriptive function names often replaces these tiny comments.
>   Apply common sense as always.
> 
>  
> Documenting locking requirements
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>   Documenting locking requirements is a good thing, but comments are not
>   necessarily the best choice. Instead of writing::
> 
> 	/* Caller must hold foo->lock */
> 	void func(struct foo *foo)
> 	{
> 		...
> 	}
> 
>   Please use::
> 
> 	void func(struct foo *foo)
> 	{
> 		lockdep_assert_held(&foo->lock);
> 		...
> 	}
> 
>   In PROVE_LOCKING kernels, lockdep_assert_held() emits a warning
>   if the caller doesn't hold the lock.  Comments can't do that.
> 
> Bracket rules
> ^^^^^^^^^^^^^
> 
> Brackets should be omitted only if the statement which follows 'if', 'for',
> 'while' etc. is truly a single line::
> 
> 	if (foo)
> 		do_something();
> 
> The following is not considered to be a single line statement even
> though C does not require brackets::
> 
> 	for (i = 0; i < end; i++)
> 		if (foo[i])
> 			do_something(foo[i]);
> 
> Adding brackets around the outer loop enhances the reading flow::
> 
> 	for (i = 0; i < end; i++) {
> 		if (foo[i])
> 			do_something(foo[i]);
> 	}
> 
> 
> Variable declarations
> ^^^^^^^^^^^^^^^^^^^^^
> 
> The preferred ordering of variable declarations at the beginning of a
> function is reverse fir tree order::
> 
> 	struct long_struct_name *descriptive_name;
> 	unsigned long foo, bar;
> 	unsigned int tmp;
> 	int ret;
> 
> The above is faster to parse than the reverse ordering::
> 
> 	int ret;
> 	unsigned int tmp;
> 	unsigned long foo, bar;
> 	struct long_struct_name *descriptive_name;
> 
> And even more so than random ordering::
> 
> 	unsigned long foo, bar;
> 	int ret;
> 	struct long_struct_name *descriptive_name;
> 	unsigned int tmp;
> 
> Also please try to aggregate variables of the same type into a single
> line. There is no point in wasting screen space::
> 
> 	unsigned long a;
> 	unsigned long b;
> 	unsigned long c;
> 	unsigned long d;
> 
> It's really sufficient to do::
> 
> 	unsigned long a, b, c, d;
> 
> Please also refrain from introducing line splits in variable declarations::
> 
> 	struct long_struct_name *descriptive_name = container_of(bar,
> 						      struct long_struct_name,
> 	                                              member);
> 	struct foobar foo;
> 
> It's way better to move the initialization to a separate line after the
> declarations::
> 
> 	struct long_struct_name *descriptive_name;
> 	struct foobar foo;
> 
> 	descriptive_name = container_of(bar, struct long_struct_name, member);
> 
> 
> Variable types
> ^^^^^^^^^^^^^^
> 
> Please use the proper u8, u16, u32, u64 types for variables which are meant
> to describe hardware or are used as arguments for functions which access
> hardware. These types are clearly defining the bit width and avoid
> truncation, expansion and 32/64-bit confusion.
> 
> u64 is also recommended in code which would become ambiguous for 32-bit
> kernels when 'unsigned long' would be used instead. While in such
> situations 'unsigned long long' could be used as well, u64 is shorter
> and also clearly shows that the operation is required to be 64 bits wide
> independent of the target CPU.
> 
> Please use 'unsigned int' instead of 'unsigned'.
> 
> 
> Constants
> ^^^^^^^^^
> 
> Please do not use literal (hexa)decimal numbers in code or initializers.
> Either use proper defines which have descriptive names or consider using
> an enum.
> 
> 
> Struct declarations and initializers
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> Struct declarations should align the struct member names in a tabular
> fashion::
> 
> 	struct bar_order {
> 		unsigned int	guest_id;
> 		int		ordered_item;
> 		struct menu	*menu;
> 	};
> 
> Please avoid documenting struct members within the declaration, because
> this often results in strangely formatted comments and the struct members
> become obfuscated::
> 
> 	struct bar_order {
> 		unsigned int	guest_id; /* Unique guest id */
> 		int		ordered_item;
> 		/* Pointer to a menu instance which contains all the drinks */
> 		struct menu	*menu;
> 	};
> 
> Instead, please consider using the kernel-doc format in a comment preceding
> the struct declaration, which is easier to read and has the added advantage
> of including the information in the kernel documentation, for example, as
> follows::
> 
> 
> 	/**
> 	 * struct bar_order - Description of a bar order
> 	 * @guest_id:		Unique guest id
> 	 * @ordered_item:	The item number from the menu
> 	 * @menu:		Pointer to the menu from which the item
> 	 *  			was ordered
> 	 *
> 	 * Supplementary information for using the struct.
> 	 *
> 	 * Note, that the struct member descriptors above are arranged
> 	 * in a tabular fashion.
> 	 */
> 	struct bar_order {
> 		unsigned int	guest_id;
> 		int		ordered_item;
> 		struct menu	*menu;
> 	};
> 
> Static struct initializers must use C99 initializers and should also be
> aligned in a tabular fashion::
> 
> 	static struct foo statfoo = {
> 		.a		= 0,
> 		.plain_integer	= CONSTANT_DEFINE_OR_ENUM,
> 		.bar		= &statbar,
> 	};
> 
> Note that while C99 syntax allows the omission of the final comma,
> we recommend the use of a comma on the last line because it makes
> reordering and addition of new lines easier, and makes such future
> patches slightly easier to read as well.
> 
> Line breaks
> ^^^^^^^^^^^
> 
> Restricting line length to 80 characters makes deeply indented code hard to
> read.  Consider breaking out code into helper functions to avoid excessive
> line breaking.
> 
> The 80 character rule is not a strict rule, so please use common sense when
> breaking lines. Especially format strings should never be broken up.
> 
> When splitting function declarations or function calls, then please align
> the first argument in the second line with the first argument in the first
> line::
> 
>   static int long_function_name(struct foobar *barfoo, unsigned int id,
> 				unsigned int offset)
>   {
> 
> 	if (!id) {
> 		ret = longer_function_name(barfoo, DEFAULT_BARFOO_ID,
> 					   offset);
> 	...
> 
> Namespaces
> ^^^^^^^^^^
> 
> Function/variable namespaces improve readability and allow easy
> grepping. These namespaces are string prefixes for globally visible
> function and variable names, including inlines. These prefixes should
> combine the subsystem and the component name such as 'x86_comp\_',
> 'sched\_', 'irq\_', and 'mutex\_'.
> 
> This also includes static file scope functions that are immediately put
> into globally visible driver templates - it's useful for those symbols
> to carry a good prefix as well, for backtrace readability.
> 
> Namespace prefixes may be omitted for local static functions and
> variables. Truly local functions, only called by other local functions,
> can have shorter descriptive names - our primary concern is greppability
> and backtrace readability.
> 
> Please note that 'xxx_vendor\_' and 'vendor_xxx_` prefixes are not
> helpful for static functions in vendor-specific files. After all, it
> is already clear that the code is vendor-specific. In addition, vendor
> names should only be for truly vendor-specific functionality.
> 
> As always apply common sense and aim for consistency and readability.
> 
> 
> Commit notifications
> --------------------
> 
> The tip tree is monitored by a bot for new commits. The bot sends an email
> for each new commit to a dedicated mailing list
> (``linux-tip-commits@vger.kernel.org``) and Cc's all people who are
> mentioned in one of the commit tags. It uses the email message ID from the
> Link tag at the end of the tag list to set the In-Reply-To email header so
> the message is properly threaded with the patch submission email.
> 
> The tip maintainers and submaintainers try to reply to the submitter
> when merging a patch, but they sometimes forget or it does not fit the
> workflow of the moment. While the bot message is purely mechanical, it
> also implies a 'Thank you! Applied.'.
> 
> -- 
> Regards/Gruss,
>     Boris.
> 
> https://people.kernel.org/tglx/notes-about-netiquette

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette