Remove _Thread_queue_Extract_with_proxy() and move the proxy extraction
to _Thread_MP_Extract_proxy(). Move similar code blocks of the previous
caller of _Thread_queue_Extract_with_proxy() to helper functions.
Update #4546.
Return an error status for the following error condition in
rtems_scheduler_remove_processor():
While an attempt is made to remove a processor from a scheduler, while
the processor is the only processor owned by the scheduler, if a thread
exists which uses the scheduler as a helping scheduler, then the
processor shall not be removed.
The reason is that ask for help requests and withdraw node requests are
processed asynchronously in any order. An ask for help request carried
out on a scheduler without a processor is undefined behaviour.
Update error status description.
Update #4544.
Process ask for help requests on the current processor. This avoids
using inter-processor interrupts to make the system behaviour a bit more
predictable.
Update #4531.
Simplify callers of _Scheduler_SMP_Schedule_highest_ready(). Move the node
state change and the extraction from scheduled into
_Scheduler_SMP_Schedule_highest_ready(). Move the idle thread release to the
caller which have more information about the presence of an idle thread.
Update #4531.
This patch fixes an issue with the idle thread handling in the SMP
scheduler framework used for the MrsP locking protocol. The approach to
use a simple chain of unused idle threads is broken for schedulers which
support thread to processor affinity. The reason is that the thread to
processor affinity introduces another ordering indicator which may under
certain conditions lead to a reordering of idle threads in the scheduled
chain. This reordering is not propagated to the chain of unused idle
threads. This could lead to use an idle thread for a sticky scheduler
node which is already in use. This locks up the system in infinite
loops in the thread context switch procedure.
To fix this, the SMP scheduler implementations must now provide
callbacks to get and release an unused idle thread.
Update #4531.
This patch fixes the following broken behaviour:
While a thread is scheduled on a helping scheduler, while it does not
own a MrsP semaphore, if it obtains a MrsP semaphore, then no
scheduler node using an idle thread and the ceiling priority of the
semaphore is unblocked for the home scheduler.
This could lead to priority inversion issues and is not in line
with the MrsP protocol.
Introduce two new scheduler operations which are only enabled if
RTEMS_SMP is defined. The operations are used to make the scheduler
node of the home scheduler sticky and to clean the sticky property.
This helps to keep the sticky handing out of the frequently used
priority update operation.
Close#4532.
Rework the handling of the affine ready queue for the EDF SMP scheduler.
Do the queue handling in the node insert, move, and extract operations.
Remove the queue handling from _Scheduler_EDF_SMP_Allocate_processor().
Update #4531.
Insert nodes after moving the second node to reduce the items in the
data structure for the insert operation. This also avoids having two
nodes for the same processor inserted into the scheduled chain.
Update #4531.
Do not set the CPU of the idle thread in _Scheduler_Use_idle_thread(). This
helps to use _Scheduler_Try_to_schedule_node() under more general conditions in
the future, for example in case the owner and user of a node are not the same.
Update #4531.
If we block the executing thread and it is not the heir thread, then there is
no need to run the schedule operation. The scheduler already selected a new
heir.
Ensure when both RTEMS_DEBUG is specified and pointers are large that
enough space is allocated to accomodate the Per_CPU_Control structure.
This changes the calculation to be more compositional instead of trying
to list out every permutation of options possible.
Check all IO driver table configuration options which are used to initialize
_IO_Driver_address_table[]. Checks for the following settings were missing:
* CONFIGURE_BSP_PREREQUISITE_DRIVERS
* CONFIGURE_APPLICATION_PREREQUISITE_DRIVERS
* CONFIGURE_APPLICATION_NEEDS_WATCHDOG_DRIVER
* CONFIGURE_APPLICATION_EXTRA_DRIVERS
Update #3875.
Evaluate CONFIGURE_DISABLE_BSP_SETTINGS for each affected application
configuration option. This makes the code easier to review since the influence
of CONFIGURE_DISABLE_BSP_SETTINGS is locally visible in the code.
Update #3875.
Priority ceiling semaphores (in contrast to MrsP semaphores) have only
one priority ceiling which is defined for the home scheduler of the task
which created the semaphore. Always check during a semaphore seize that
the home scheduler of the calling task is equal to this scheduler.
This avoids a scheduler mismatch if the semphore is acquired after the
calling thread blocked on the semaphore.
This patch set replaces the CPU budget algorithm enumeration with a set of CPU
budget operations which implement a particular CPU budget algorithm. This
helps to hide the CPU budget algorithm implementation details from the general
thread handling. The CPU budget callouts are turned into CPU budget
operations. This slightly reduces the size of the thread control block.
All schedulers used the default scheduler tick implementation. The tick
scheduler operation is removed and the CPU budget operations are directly used
in _Watchdog_Tick() if the executing thread uses a CPU budget algorithm. This
is performance improvement for all threads which do not use a CPU budget
algorithm (default behaviour).
This adds a confdef option allowing an application to request mapping
machine exceptions to POSIX signals. This is required for some languages
such as Ada.
Mention that resetting the processor usage time of tasks has no impact
on the period status and statistics.
Remove no longer relevant RTEMS_NOT_DEFINED error status.
Update #4528.
The rate monotonic period statistics were affected by
rtems_cpu_usage_reset(). The logic to detect and work around a CPU
usage reset was broken.
The Thread_Contol::cpu_time_used is changed to contain the processor
time used throughout the entire lifetime of the thread. The new member
Thread_Contol::cpu_time_used_at_last_reset is added to contain the
processor time used at the time of the last reset through
rtems_cpu_usage_reset(). This decouples the resets of the CPU usage and
the rate monotonic period statistics.
Update #4528.
Add a stack allocator hook specifically for allocation of IDLE thread stacks.
This allows the user to decide if IDLE thread stacks are statically allocated
or handled by the same custom allocator mechanism as other thread stacks.
Closes#4524.
The schedule operation is only called by rtems_task_mode(). It is
called if preempt mode of the executing thread changes from disabled to
enabled. Since the EDF SMP scheduler does not support the disabled
preemption mode, the schedule operation is never called.
Sebastian Huber
Kinsey Moore
Joel Sherrill