26.21. Multiprocessing Configuration

This section describes multiprocessing related configuration options. The options are only used if RTEMS was built when the multiprocessing build configuration option is enabled. The multiprocessing configuration is distinct from the SMP configuration. Additionally, this class of configuration options are only applicable if the configuration option CONFIGURE_MP_APPLICATION is defined. The multiprocessing (MPCI) support must not be confused with the SMP support.

26.21.1. CONFIGURE_EXTRA_MPCI_RECEIVE_SERVER_STACK

CONSTANT:

CONFIGURE_EXTRA_MPCI_RECEIVE_SERVER_STACK

OPTION TYPE:

This configuration option is an integer define.

DEFAULT VALUE:

The default value is 0.

DESCRIPTION:

The value of this configuration option defines the number of bytes the applications wishes to add to the MPCI task stack on top of CONFIGURE_MINIMUM_TASK_STACK_SIZE.

NOTES:

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The following constraints apply to this configuration option:

  • The value of the configuration option shall be greater than or equal to zero.

  • The value of the configuration option shall be less than or equal to UINT32_MAX.

  • The value of the configuration option shall be small enough so that the MPCI receive server stack area calculation carried out by <rtems/confdefs.h> does not overflow an integer of type size_t.

26.21.2. CONFIGURE_MP_APPLICATION

CONSTANT:

CONFIGURE_MP_APPLICATION

OPTION TYPE:

This configuration option is a boolean feature define.

DEFAULT CONFIGURATION:

If this configuration option is undefined, then the multiprocessing services are not initialized.

DESCRIPTION:

This configuration option is defined to indicate that the application intends to be part of a multiprocessing configuration. Additional configuration options are assumed to be provided.

NOTES:

This configuration option shall be undefined if the multiprocessing support is not enabled (e.g. RTEMS was built without the multiprocessing build configuration option enabled). Otherwise a compile time error in the configuration file will occur.

26.21.3. CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS

CONSTANT:

CONFIGURE_MP_MAXIMUM_GLOBAL_OBJECTS

OPTION TYPE:

This configuration option is an integer define.

DEFAULT VALUE:

The default value is 32.

DESCRIPTION:

The value of this configuration option defines the maximum number of concurrently active global objects in a multiprocessor system.

NOTES:

This value corresponds to the total number of objects which can be created with the RTEMS_GLOBAL attribute.

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The following constraints apply to this configuration option:

  • The value of the configuration option shall be greater than or equal to zero.

  • The value of the configuration option shall be less than or equal to UINT32_MAX.

26.21.4. CONFIGURE_MP_MAXIMUM_NODES

CONSTANT:

CONFIGURE_MP_MAXIMUM_NODES

OPTION TYPE:

This configuration option is an integer define.

DEFAULT VALUE:

The default value is 2.

DESCRIPTION:

The value of this configuration option defines the maximum number of nodes in a multiprocessor system.

NOTES:

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The following constraints apply to this configuration option:

  • The value of the configuration option shall be greater than or equal to zero.

  • The value of the configuration option shall be less than or equal to UINT32_MAX.

26.21.5. CONFIGURE_MP_MAXIMUM_PROXIES

CONSTANT:

CONFIGURE_MP_MAXIMUM_PROXIES

OPTION TYPE:

This configuration option is an integer define.

DEFAULT VALUE:

The default value is 32.

DESCRIPTION:

The value of this configuration option defines the maximum number of concurrently active thread/task proxies on this node in a multiprocessor system.

NOTES:

Since a proxy is used to represent a remote task/thread which is blocking on this node. This configuration parameter reflects the maximum number of remote tasks/threads which can be blocked on objects on this node, see Proxies.

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The following constraints apply to this configuration option:

  • The value of the configuration option shall be greater than or equal to zero.

  • The value of the configuration option shall be less than or equal to UINT32_MAX.

26.21.6. CONFIGURE_MP_MPCI_TABLE_POINTER

CONSTANT:

CONFIGURE_MP_MPCI_TABLE_POINTER

OPTION TYPE:

This configuration option is an initializer define.

DEFAULT VALUE:

The default value is &MPCI_table.

DESCRIPTION:

The value of this configuration option initializes the MPCI Configuration Table.

NOTES:

RTEMS provides a Shared Memory MPCI Device Driver which can be used on any Multiprocessor System assuming the BSP provides the proper set of supporting methods.

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The value of the configuration option shall be a pointer to rtems_mpci_table.

26.21.7. CONFIGURE_MP_NODE_NUMBER

CONSTANT:

CONFIGURE_MP_NODE_NUMBER

OPTION TYPE:

This configuration option is an integer define.

DEFAULT VALUE:

The default value is NODE_NUMBER.

DESCRIPTION:

The value of this configuration option defines the node number of this node in a multiprocessor system.

NOTES:

In the RTEMS Multiprocessing Test Suite, the node number is derived from the Makefile variable NODE_NUMBER. The same code is compiled with the NODE_NUMBER set to different values. The test programs behave differently based upon their node number.

This configuration option is only evaluated if CONFIGURE_MP_APPLICATION is defined.

CONSTRAINTS:

The following constraints apply to this configuration option:

  • The value of the configuration option shall be greater than or equal to zero.

  • The value of the configuration option shall be less than or equal to UINT32_MAX.