[PATCH 8/8] score: Add scheduler assignments for SMP

[Sebastian Huber]

On 04/11/2014 07:27 PM, Gedare Bloom wrote:
> [...]
>> diff --git a/doc/user/conf.t b/doc/user/conf.t
>> index 9b093f8..e3c3f24 100644
>> --- a/doc/user/conf.t
>> +++ b/doc/user/conf.t
>> @@ -3792,6 +3792,99 @@ guidance.  For guidance on the configuration macros, please examine
>>   Deterministic Priority Scheduler.
>>
>>   @c
>> + at c === Configuring Partitioned/Clustered Schedulers ===
>> + at c
>> + at subsection Configuring Partitioned/Clustered Schedulers
>> +
>> +Partitioned/clustered scheduling helps to control the worst-case latencies in
>> +the system.  The goal is to reduce the amount of shared state in the system and
>> +thus prevention of lock contention.  Modern multi-processor systems tend to
>> +have several layers of data and instruction caches.  With partitioned/clustered
>> +scheduling it is possible to honor the cache topology of a system and thus
>> +avoid expensive cache synchronization traffic.
>> +
>> +The schedulers in an SMP system are statically configured.  First the
>> +application must select which scheduling algorithms are available with the
>> +following defines
>> +
>> + at itemize @bullet
>> + at item @code{CONFIGURE_SCHEDULER_PRIORITY_SMP},
>> + at item @code{CONFIGURE_SCHEDULER_SIMPLE_SMP}, and
>> + at item @code{CONFIGURE_SCHEDULER_PRIORITY_AFFINITY_SMP}.
>> + at end itemize
>> +
>> +After these definitions the configuration file must
>> + at code{#include <rtems/scheduler.h>} to have access to scheduler specific
>> +configuration macros.  Each scheduler needs a context to store state
>> +information at run-time.  To provide a context for each scheduler is the next
>> +step.  Use the following macros to create scheduler contexts
>> +
>> + at itemize @bullet
>> + at item @code{RTEMS_SCHEDULER_CONTEXT_PRIORITY_SMP},
>> + at item @code{RTEMS_SCHEDULER_CONTEXT_SIMPLE_SMP}, and
>> + at item @code{RTEMS_SCHEDULER_CONTEXT_PRIORITY_AFFINITY_SMP}.
>> + at end itemize
>> +
>> +The schedulers are registered in the system via the scheduler table.  To create
>> +the scheduler table define @code{CONFIGURE_SCHEDULER_CONTROLS} to a list of the
>> +following scheduler control initializers
>> +
>> + at itemize @bullet
>> + at item @code{RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP},
>> + at item @code{RTEMS_SCHEDULER_CONTROL_SIMPLE_SMP}, and
>> + at item @code{RTEMS_SCHEDULER_CONTROL_PRIORITY_AFFINITY_SMP}.
>> + at end itemize
>> +
>> +The last step is to define which processor uses which scheduler.  For this
>> +purpose a scheduler assignment table must be defined.  The entry count of this
>> +table must be equal to the configured maximum processors
>> +(@code{CONFIGURE_SMP_MAXIMUM_PROCESSORS}).  A processor assignment to a
>> +scheduler can be optional or mandatory.  The boot processor must have a
>> +scheduler assigned.  In case the system needs more mandatory processors than
>> +available then a fatal run-time error will occur.  To specify the scheduler
>> +assignments define @code{CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS} to a list of
>> + at code{RTEMS_SCHEDULER_ASSIGN} macros.
>> +
>> +The following example shows a partitioned scheduler configuration for two
>> +processors.  Each processor is owned by a Deterministic Priority scheduler
>> +capable to manage 256 priority levels.  The scheduler with index zero has the
>> +name @code{"BLUE"}.  The scheduler with index one has the name @code{"WOOD"}.
>> +The scheduler assignments are mandatory, so the system must have at least two
>> +processors, otherwise a fatal run-time error will occur during system startup.
>> +
>> + at example
>> + at group
>> +#define CONFIGURE_SMP_APPLICATION
>> +
>> +#define CONFIGURE_SMP_MAXIMUM_PROCESSORS 2
>> +
>> +#define CONFIGURE_MAXIMUM_PRIORITY 255
>> +
>> +#define CONFIGURE_SCHEDULER_PRIORITY_SMP
>> +
>> +#include <rtems/scheduler.h>
>> +
>> +RTEMS_SCHEDULER_CONTEXT_PRIORITY_SMP(a, CONFIGURE_MAXIMUM_PRIORITY + 1);
>> +
>> +RTEMS_SCHEDULER_CONTEXT_PRIORITY_SMP(b, CONFIGURE_MAXIMUM_PRIORITY + 1);
>> +
>> +#define CONFIGURE_SCHEDULER_CONTROLS \
>> +  RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \
>> +    a, \
>> +    rtems_build_name('B', 'L', 'U', 'E') \
>> +  ), \
>> +  RTEMS_SCHEDULER_CONTROL_PRIORITY_SMP( \
>> +    b, \
>> +    rtems_build_name('W', 'O', 'O', 'D') \
>> +  )
>> +
>> +#define CONFIGURE_SMP_SCHEDULER_ASSIGNMENTS \
>> +  RTEMS_SCHEDULER_ASSIGN(0, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY), \
>> +  RTEMS_SCHEDULER_ASSIGN(1, RTEMS_SCHEDULER_ASSIGN_PROCESSOR_MANDATORY)
>> + at end group
>> + at end example
>> +
> Make it more clear in the documentation that the index passed to
> RTEMS_SCHEDULER_ASSIGN identifies the scheduler based on the order
> they are defined in the CONFIGURE_SCHEDULER_CONTROLS, and that the
> order of the assignments implies the processor being assigned.
>
> -Gedare

Ok.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.