After a k_thread_abort(), the resulting thread struct is documented as
unused/free memory that may be re-used (for example, to respawn a new
thread).
But in the special case of aborting the current thread from within an
ISR, that wasn't quite happening. The scheduler cleanup would
complete, but the architecture layer would still try to context switch
away from the aborted thread on exit, and that can include writes to
the now-reused thread struct! The specifics will depend on
architecture (some do a full context save on entry, most don't), but
in the case of USE_SWITCH=y it will at the very least write the
switch_handle field.
Fix this simply, with a per-cpu "switch dummy" thread struct for use
as a target for context switches like this. There is some non-trivial
memory cost to that; thread structs on many architectures are large.
Pleasingly, this also addresses a known deadlock on SMP: because the
"spin in ISR" step now happens as the very last stage of
k_thread_abort() handling, the existing scheduler lock works to
serialize calls such that it's impossible for a cycle of threads to
independently decide to spin on each other: at least one will see
itself as "already aborting" and break the cycle.
Fixes#64646
Signed-off-by: Andy Ross <andyross@google.com>
Spinlocks taken in ISRs were storing the _current thread pointer of
the interrupted thread as the owner, which was never strictly correct
but was benign as the thread would never run until the lock was
released.
But now k_thread_abort(_current) in an ISR has been fixed to eliminate
all references to the (now aborted) thread struct, and _current points
to a dummy thread. Handle that edge case in the validation framework.
Signed-off-by: Andy Ross <andyross@google.com>
Big change is to factor out a thread_halt_spin() utility to manage the
core complexity of this code: the situation where an ISR is asked to
abort a thread already running on another SMP CPU.
With that gone, things can be cleaned up quite a bit. Remove early
returns, most of the "#if CONFIG_SMP" usage was superfluous and will
optimize out, unify and clean up the comments, etc...
No behavioral changes (hopefully), just refactoring.
Signed-off-by: Andy Ross <andyross@google.com>
After the move to C files we got some drop in the performance when
running latency_measure. This patch declares the priority queue
functions as static inlines with minor optimizations.
The result for one metric (on qemu):
3.6 and before the anything was changed:
Get data from LIFO (w/ ctx switch): 13087 ns
after original change (46484da502):
Get data from LIFO (w/ ctx switch): 13663 ns
with this change:
Get data from LIFO (w/ ctx switch): 12543 ns
So overall, a net gain of ~ 500ns that can be seen across the board on many
of the metrics.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Check possible overflow in k_stack data struct. An overflow
can happens resulting in a much smaller amount of memory allocation.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Currently, all devices are initialized at boot time (following their
level and priority order). This patch introduces deferred
initialization: by setting the property `zephyr,deferred-init` on a
device on the devicetree, Zephyr will not initialized the device.
To initialize such devices, one has to call `device_init()`.
Deferred initialization is done by grouping all deferred devices on a
different ELF section. In this way, there's no need to consume more
memory to keep track of deferred devices. When `device_init()` is
called, Zephyr will scan the deferred devices section and call the
initialization function for the matching device. As this scanning is
done only during deferred device initialization, its cost should be
bearable.
Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>
This introduces support for memory mapped thread stacks,
where each thread stack is mapped into virtual memory
address space with two guard pages to catch
under-/over-flowing the stack. This is just on the kernel
side. Additional architecture code is required to fully
support this feature.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This is similar to k_mem_map()/_unmap(). But instead of using
anonymous memory, the provided physical region is mapped
into virtual address instead. In addition to simple mapping
physical ro virtual addresses, the mapping also adds two
guard pages before and after the virtual region to catch
buffer under-/over-flow.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This adds the mechanism to do cleanup after k_thread_abort()
is called with the current thread. This is mainly used for
cleaning up things when the thread cannot be running, e.g.,
cleanup the thread stack.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Next timeout was set unconditionally at the end of sys_clock_announce.
However, if one of the current expired timeouts was setting a new
timeout which is the first to execute then system clock was configured
twice. Lets configure system clock only once in the isr at the and of
sys_clock_announce.
If timeouts are frequent this optimization can reduce CPU load. In
many cases setting the new sys_clock timeout is the most time
consuming operation in the sys_clock isr handler. As an example,
on the target I used setting new sys_clock timeout is taking 6 uS of
9 uS spent in the isr and it takes 16 uS with the redundant call.
Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>
Do not build threading support when CONFIG_MULTITHREADING=n is set and
move needed calls to a new file with the changes needed instead of the
ifdef party in sched.c
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The `BUILD_VERSION` can be defined but empty when built
without git, causing version to be missing from the banner:
```
*** Booting Zephyr OS build ***
Hello World! qemu_riscv64
```
Let's check if it is empty before using it, so that
`KERNEL_VERSION_STRING`, which is generated independently
with cmake can be used as a fallback:
```
*** Booting Zephyr OS build 3.5.0 ***
Hello World! qemu_riscv64
```
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
When thread stack is defined as an array, K_THREAD_STACK_LEN()
is used to calculate the size for each stack in the array.
However, standalone thread stack has its size calculated by
Z_THREAD_STACK_SIZE_ADJUST() instead. Depending on the arch
alignment requirement, they may not be the same... which
could cause some confusions. So align them both to use
K_THREAD_STACK_LEN().
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
When kernel stack is defined as an array, K_KERNEL_STACK_LEN()
is used to calculate the size for each stack in the array.
However, standalone kernel stack has its size calculated by
Z_KERNEL_STACK_SIZE_ADJUST() instead. Depending on the arch
alignment requirement, they may not be the same... which
could cause some confusions. So align them both to use
K_KERNEL_STACK_LEN().
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Simple rename to align the kernel naming scheme. This is being
used throughout the tree, especially in the architecture code.
As this is not a private API internal to kernel, prefix it
appropriately with K_.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Simple rename to align the kernel naming scheme. This is being
used throughout the tree, especially in the architecture code.
As this is not a private API internal to kernel, prefix it
appropriately with K_.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Differently from other libraries, which are included whole in the final
Zephyr ELF, libkernel.a itself isn't. Assuming this is intended to
enable optimisations (if it isn't, this patch will break things) - linker
can remove parts of the kernel that are not used by the application.
However, when considering Linkable Loadable Extensions (llext), this
optimisations can be counterproductive: for instance, syscalls that are
not used by the application won't be available for extensions. It won't
matter if someone "EXPORT_SYMBOL" for them, or even try to keep them
using LINKER_KEEP, they'll be gone.
To avoid that, this patches includes, when CONFIG_LLEXT=y, libkernel.a
inside the linker "whole-archive" block. This ends up making it consider
libkernel.a as a library whose all symbols should be kept. Note this
doesn't mean that all symbols will be there - things compiled out via
Kconfig will naturally still be out.
Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>
Add a closing comment to the endif with the configuration
information to which the endif belongs too.
To make the code more clearer if the configs need adaptions.
Signed-off-by: Simon Hein <Shein@baumer.com>
arch_interface.h is for architecture and should not be
under sys/. So move it under include/zephyr/arch/.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
k_mem_map additionally allocates two guard pages that are not mapped.
These pages are not being accounted when checking the provided size and
when they are added an overflow can happen and the mapped memory is not
correct.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Linkable loadable extensions can only use syscalls if they are exported
via EXPORT_SYSCALL (or EXPORT_SYMBOL). Instead of enabling used syscalls
one by one, this patch exports all of them automatically via
`gen_syscalls.py`. If CONFIG_LLEXT=n, the section where the exported
symbols live is discarded, so it should be a non-op when llext is not
enabled.
This patch also removes the now redundant EXPORT_SYSCALL macro. Note
that EXPORT_SYMBOL is still useful on different situations (and is
indeed used by the code generated by `gen_syscalls.py`).
Signed-off-by: Ederson de Souza <ederson.desouza@intel.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>
k_thread_deadline_set() would modify the thread's deadline and then,
if it was in the run queue, requeue it to put it at the right spot.
Sounds right, right?
It's wrong. The deadline field is part of the thread priority, so
this results in a mis-ordered list. For dlist backends, that's benign
as the removal works anyway, but if CONFIG_SCHED_SCALABLE=y we've now
broken the sorting order of an in-tree item and corrupted the rbtree!
Fixes#69935
Signed-off-by: Andy Ross <andyross@google.com>
This currently calls timeout_rem() then adds back the result of
elapsed() to cancel out the subtraction of another elapsed() call
within timeout_rem(). Better not to make any calls to elapsed() in
that case, especially given that elapsed() may incur hardware access
overhead through sys_clock_elapsed().
Let's move the elapsed() subtraction to the only user of timeout_rem()
that needs it and remove its invocation from the z_timeout_expires()
path entirely.
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
The code `SYS_SLIST_FOR_EACH_CONTAINER_SAFE` just for remove work
from `pending_cancels`.
After removing work successfully, the function can return early.
It is unnecessary to iterate continuously.
Signed-off-by: TaiJu Wu <tjwu1217@gmail.com>
Rename private function to make it clear what priority we are setting
and to be consistent across the code.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Avoid single characker variables that renders code unreadable and might
cause conflicts in maing, similar to t for both timeout and thread in
some places.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Use thread wherever it makes sense, using 't' in some places can get
confused with 't' used for timeouts for example.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Move thread monitor related functions, not enabled in most cases outside
of thread.c and cleanup headers.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This function is only being used by a test, so instead of reimplementing
a syscall in the test, provide a Kconfig option to provide the
functionality that only works with tests and remove some of the
duplication and extra code.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Move out of thread and put directly in init.c where it is being used.
Also remove definition from kernel.h, this is an internal function and
should not be in a public header.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
We shouldn't be calling hooks from optional and upper layer subsystems
in the kernel, instead, just call the hook to set thread status in the
API where it is needed.
This now clears related bit in cmsis thread status bitarray when
terminating a thread in the cmsis rtos v1 layer directly and not in the
kenrel code.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
In an effort to cleanup sched.c, move sections of code that can be
compiled in based on options into own files. CPU mask here is managed by
a kconfig and is not widely used (SMP affinity on multicore systems).
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The kernel kconfig is becoming too big and unmanageable with too many
options scattered across the file. Move some areas out and reorg main
Kconfig slightly.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
