Add per-CPU profiling stats API. Implement the thread dispatch disable
level profiling. The interrupt profiling must be implemented in CPU
port specific parts (mostly assembler code). Add a support function
_Profiling_Outer_most_interrupt_entry_and_exit() for this purpose.
Add a local context structure to the SMP lock API for acquire and
release pairs. This context can be used to store the ISR level and
profiling information. It may be later used to enable more
sophisticated lock algorithms, e.g. MCS locks.
There is only one lock that cannot be used with a local context. This
is the per-CPU lock since here we would have to transfer the local
context through a context switch which is very complicated.
This partially reverts commit 1215fd4d94.
In order to support profiling of SMP locks and provide a future
compatible SMP locks API it is necessary to add an SMP lock destroy
function. Since the commit above adds an SMP lock to each chain control
we would have to add a rtems_chain_destroy() function as well. This
complicates the chain usage dramatically. Thus revert the patch above.
A global SMP lock for all chains is used to implement the protected
chain operations.
Advantages:
* The SAPI chain API is now identical on SMP and non-SMP
configurations.
* The size of the chain control is reduced and is then equal to the
Score chains.
* The protected chain operations work correctly on SMP.
Disadvantage:
* Applications using many different chains and the protected operations
may notice lock contention.
The chain control size drop is a huge benefit (SAPI chain controls are
66% larger than the Score chain controls). The only disadvantage is not
really a problem since these applications can use specific interrupt
locks and unprotected chain operations to avoid this issue.
Formerly POSIX keys were only enabled when POSIX threads
were enabled. Because they are a truly safe alternative
to per-task variables in an SMP system, they are being
enabled in all configurations.
SMP must be initialized in order to know the current set of
cores available. Without this, you cannot initialize the
default cpu_set_t associated with Classic API tasks and
POSIX threads.
Rename _SMP_Request_other_cores_to_perform_first_context_switch() into
_SMP_Request_start_multitasking() since this requests now a multitasking
start on all configured and available processors. The name corresponds
_Thread_Start_multitasking() and
_SMP_Start_multitasking_on_secondary_processor() actions issued in
response to this request. Move in source file to right place.
Rename PER_CPU_STATE_READY_TO_BEGIN_MULTITASKING into
PER_CPU_STATE_READY_TO_START_MULTITASKING.
Rename PER_CPU_STATE_BEGIN_MULTITASKING into
PER_CPU_STATE_REQUEST_START_MULTITASKING.
Rename _SMP_Request_other_cores_to_shutdown() into
_SMP_Request_shutdown().
Add a per-CPU state lock to protect all changes. This was necessary to
offer a controlled shutdown of the system (atomic read/writes alone are
not sufficient for this kind of synchronization).
Add documentation for Per_CPU_State.
Delete debug output.
New tests smptests/smpfatal01 and smptests/smpfatal02.
Use rtems_fatal() instead of _CPU_Fatal_halt() to shutdown processors in
SMP configurations since this allows intervention of BSP or application
specific fatal extensions.
Merge RTEMS_FATAL_SOURCE_BSP_GENERIC and RTEMS_FATAL_SOURCE_BSP_SPECIFIC
into new fatal source RTEMS_FATAL_SOURCE_BSP. This makes it easier to
figure out the code position given a fatal source and code.
Move _SMP_Request_other_cores_to_shutdown() invocation from
rtems_shutdown_executive() to _Internal_error_Occurred() to allow a
proper shutdown on SMP configurations even in the error case.
Do not return to BSP context in the exit() shutdown path. This makes it
possible to re-use the initialization stack. It can be used for the
interrupt stack for example. On targets with a small RAM this is a
considerable benefit.
This change eliminates also some special cases and simplifies the code.
Delete _Thread_Set_global_exit_status(),
_Thread_Get_global_exit_status() and _Thread_Stop_multitasking().
Merge systems states SYSTEM_STATE_SHUTDOWN and SYSTEM_STATE_FAILED into
new system state SYSTEM_STATE_TERMINATED. This reflects that all system
termination paths end up in _Internal_error_Occurred().
Add a CPU counter interface to allow access to a free-running counter.
It is useful to measure short time intervals. This can be used for
example to enable profiling of critical low-level functions.
Add two busy wait functions rtems_counter_delay_ticks() and
rtems_counter_delay_nanoseconds() implemented via the CPU counter.
Rename rtems_internal_error_description() to
rtems_internal_error_text(). Rename rtems_fatal_source_description() to
rtems_fatal_source_text(). Rename rtems_status_code_description() to
rtems_status_text(). Remove previous implementation of
rtems_status_text().
Add ISR lock to chain control for proper SMP protection. Replace
rtems_chain_extract() with rtems_chain_explicit_extract() and
rtems_chain_insert() with rtems_chain_explicit_insert() on SMP
configurations. Use rtems_chain_explicit_extract() and
rtems_chain_explicit_insert() to provide SMP support.
Delete _Priority_bit_map_Handler_initialization() and rely on BSS
initialization. Move definition of _Priority_Major_bit_map and
_Priority_Bit_map to separate file. Move definition of __log2table also
to this file.
Change pthread_once from using disabled pre-emption to using a
pthread mutex making it SMP safe. GCC using a posix threading
model uses pthread_once.
The pthread mutex requires at least 1 mutex is configured so
confdefs.h has been updated to account for the internal
mutex.
This patch enables unlimited model in POSIX key manger and have a decent
runtime on POSIX key searching, adding and deleting operations. Memory
overhead is lower than current implementation when the size of key and key
value becomes big.
Add context parameter to _Thread_Start_multitasking() and use this
function in rtems_smp_secondary_cpu_initialize(). This avoids
duplication of code.
Fix missing floating point context initialization in
rtems_smp_secondary_cpu_initialize(). Now performed via
_Thread_Start_multitasking().
Move implementation specific parts of object.h and object.inl into new
header file objectimpl.h. The object.h contains now only the
application visible API.
Move implementation specific parts of thread.h and thread.inl into new
header file threadimpl.h. The thread.h contains now only the
application visible API.
Remove superfluous header file includes from various files.
