If there are pending readers, it is best to perform a single data copy
directly into their final destination buffer rather than doing one copy
into the ring buffer just to immediately copy the same data out of it.
Incidentally, this allows for supporting pipes with no ring buffer at all.
The pipe implementation being deprecated has a similar capability so better
have it here too.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
This commit updates the k_pipe documentation to reflect the rewritten
interface.
Changes include:
* Detailed explanations of k_pipe concepts, initialization, and usage.
* Examples for defining, writing to, reading from, flushing,
and closing a pipe.
* Clarified behavior in edge cases and introduced enhanced error-handling
details.
Updated suggested use cases and API references.
Signed-off-by: Måns Ansgariusson <Mansgariusson@gmail.com>
Mostly a revert of commit b1def7145f ("arch: deprecate `_current`").
This commit was part of PR #80716 whose initial purpose was about providing
an architecture specific optimization for _current. The actual deprecation
was sneaked in later on without proper discussion.
The Zephyr core always used _current before and that was fine. It is quite
prevalent as well and the alternative is proving rather verbose.
Furthermore, as a concept, the "current thread" is not something that is
necessarily architecture specific. Therefore the primary abstraction
should not carry the arch_ prefix.
Hence this revert.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Expands the caching documentation to include a high-level overview
of caching strategies and the features available in Zephyr.
Signed-off-by: Dane Wagner <dane.wagner@gmail.com>
The initial proposal had the assert included, however this could break
downstream users and it was opted to not add assert in the driver API
calls.
Update the documented example to reflect that.
Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>
Add a migration entry for the device driver API change, and start listing
driver classes that have been updated in-tree.
Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>
Update the device driver API documentation with the new DEVICE_API
macro definitions and how to use them.
Signed-off-by: Pieter De Gendt <pieter.degendt@basalte.be>
`_current` is now functionally equals to `arch_curr_thread()`, remove
its usage in-tree and deprecate it instead of removing it outright,
as it has been with us since forever.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Signed-off-by: Yong Cong Sin <yongcong.sin@gmail.com>
This adds a new kconfig for eviction algorithm which needs page
tracking. When enabled, k_mem_paging_eviction_add()/_remove()
and k_mem_paging_eviction_accessed() must be implemented.
If an algorithm does not do page tracking, there is no need to
implement these functions, and no need for the kernel MMU code
to call into empty functions. This should save a few function
calls and some CPU cycles.
Note that arm64 unconditionally calls those functions so
forces CONFIG_EVICTION_TRACKING to be enabled there.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Add support for realloc (and realloc_aligned) into the multi heap lib,
where the buffer sent in will either be reused (maybe shrinked),
or enlarged by allocating on any of the matching heaps of the multi heap.
Signed-off-by: Meir Komet <mskomet1@gmail.com>
The documentation of "Kernel/Data Structures" incorrectly
states that 'all provided structures are uniformly unsynchronized;
access to them is not threadsafe by default'.
In reality, some of them are threadsafe and some are not.
This might discourage users from using threadsafe data structures
where applicable, or mislead users into adding unnecessary locks.
This proposal addresses the issue by specifying thread safety
for each provided data structure.
My assessment of thread safety is based purely on source code analysis;
hence an expert verification would be appreciated.
Signed-off-by: Vukan Turkulov <vukant@gmail.com>
Up until now, the `__thread` keyword has been used for declaring
variables as Thread local storage. However, `__thread` is a GNU
specific keyword which thus limits compatibility with other
toolchains (for instance IAR).
This PR intoduces a new macro `Z_THREAD_LOCAL` which expands to the
corresponding C11, C23 or C++11 standard keyword based on the standard
that is specified during compilation, else it uses the old `__thread`
keyword.
Signed-off-by: Daniel Flodin <daniel.flodin@iar.com>
Fixes bad usage of single backticks in lieu of double backticks for
rendering inline literals, or simple '*' for italics.
When appropriate, a better construct than double backticks has been
selected (ex. :file:, :kconfig:option:, :c:func:, ...), or proper :ref:
have been used if the original intention was to have a link.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
Dangling hyphens at the end of a line are usually a problem, ie. you
have an "hyphenated-word" and breaking it on two line will render it as
"hyphenated- word".
This commit fixes the few occurences of such dangling hyphens.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
This sets initial unpaged mappings for __ondemand_func code and
__ondemand_rodata variables. To achieve this, we have to augment the
backing store API.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Fix `k_poll()` loop example by using separate `if` blocks instead of
`if`-`else`-chain to ensure all events are handled, even if multiple are
active at the same time.
Signed-off-by: Cla Mattia Galliard <cla-mattia.galliard@zuehlke.com>
Add information about main(int, argc **) in places where the documentation
stated that only parameterless main could be used
Signed-off-by: Jakub Michalski <jmichalski@internships.antmicro.com>
Signed-off-by: Filip Kokosinski <fkokosinski@antmicro.com>
Describe the samples using code-sample directive in preparation for
upcoming changes to the Zephyr documentation that will be leveraging
the provided description and metadata.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
The docs for the iterable sections has a minor typo when
describing how to add the structs to the linker, repeating
'place the' twice.
Signed-off-by: Paulo Santos <pauloroberto.santos@edge.ufal.br>
Utilize a code spell-checking tool to scan for and correct spelling errors
in various files within the `doc` directory.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
Adds a section providing additional information about IPI cascades
to the kernel's SMP documentation.
Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Also any demand paging and page frame related bits are
renamed.
This is part of a series to move memory management related
stuff out of the Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Renames:
Z_KERNEL_VIRT_START to K_MEM_KERNEL_VIRT_START
Z_KERNEL_VIRT_SIZE to K_MEM_KERNEL_VIRT_SIZE
Z_KERNEL_VIRT_END to K_MEM_KERNEL_VIRT_END
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Renames:
Z_VIRT_RAM_START to K_MEM_VIRT_RAM_START
Z_VIRT_RAM_SIZE to K_MEM_VIRT_RAM_SIZE
Z_VIRT_RAM_END to K_MEM_VIRT_RAM_END
This is part of a series to move memory management related
stuff from Z_ namespace into its own namespace.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
fixed usage of wrong C roles (e.g. `:c:struct:` instead of `:c:type:`)
which Breathe tolerates but can cause trouble when using other systems.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
Moves the rtio_ prefixed lockfree queues to sys alongside existing
mpsc/spsc pbuf, ringbuf, and similar queue-like data structures.
Signed-off-by: Tom Burdick <thomas.burdick@intel.com>
Platforms that support IPIs allow them to be broadcast via the
new arch_sched_broadcast_ipi() routine (replacing arch_sched_ipi()).
Those that also allow IPIs to be directed to specific CPUs may
use arch_sched_directed_ipi() to do so.
As the kernel has the capability to track which CPUs may need an IPI
(see CONFIG_IPI_OPTIMIZE), this commit updates the signalling of
tracked IPIs to use the directed version if supported; otherwise
they continue to use the broadcast version.
Platforms that allow directed IPIs may see a significant reduction
in the number of IPI related ISRs when CONFIG_IPI_OPTIMIZE is
enabled and the number of CPUs increases. These platforms can be
identified by the Kconfig option CONFIG_ARCH_HAS_DIRECTED_IPIS.
Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Updates the pipes documentation to generate a link to CONFIG_PIPES
Kconfig option description instead of merely listing the name of
this option.
Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Namespaced the generated headers with `zephyr` to prevent
potential conflict with other headers.
Introduce a temporary Kconfig `LEGACY_GENERATED_INCLUDE_PATH`
that is enabled by default. This allows the developers to
continue the use of the old include paths for the time being
until it is deprecated and eventually removed. The Kconfig will
generate a build-time warning message, similar to the
`CONFIG_TIMER_RANDOM_GENERATOR`.
Updated the includes path of in-tree sources accordingly.
Most of the changes here are scripted, check the PR for more
info.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
This adds a new kconfig to indicate if architecture code
supports isolating thread stacks within the same domain,
and another new kconfig to selectively enable this
behavior.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The struct z_page_frame is marked __packed to avoid extra padding as
such padding may represent significant memory waste when lots of page
frames are used. However this is a bad strategy.
The code contained this somewhat dubious comment and code in
free_page_frame_list_put():
/* The structure is packed, which ensures that this is true */
void *node = pf;
sys_slist_append(&free_page_frame_list, node);
This is bad for many reasons:
- type checking is completely bypassed;
- if the sys_snode_t node member is no longer located at the front of
struct z_page_frame then the code will still compile and possibly run
but be broken with memory corruption as a likely outcome;
- the sys_slist_append() code is completely unaware of the packed
attribute which breaks architectures with alignment restrictions.
Let's improve code efficiency as well as memory usage by removing the
packed attribute and manually packing the flags in the unused virtual
address bits. This way the page frame array remains naturally aligned,
data access becomes optimal and the actual array size gets even smaller.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Changes:
1. the number of events being checked did not equal those defined
in the `events` array.
2. Use `k_poll_signal_check()` instead of accessing fields directly.
3. Use `k_poll_signal_reset()` to reset the signal instead of
accessing fields directly.
I'm assuming the examples predate `k_poll_signal_check()` and
`k_poll_signal_reset()`
Signed-off-by: Glenn Andrews <glenn.andrews.42@gmail.com>
The Kernel code relocation example does not work, as the kernel
contains early initialization code that executes before code
relocation takes place
Signed-off-by: Grant Ramsay <gramsay@enphaseenergy.com>
Modified bitmask to bitmask array, it can make multilevel queue remove
32 bit prioriry limit.
We can scan bitmask array to find which queue have ready thread.
Only need the number of queues as priority because the priority
is checked on create_thread.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
