[rtems-docs commit] c-user: Mention per-processor data
sebh at rtems.org
Mon Sep 10 09:38:03 UTC 2018
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Fri Sep 7 15:31:31 2018 +0200
c-user: Mention per-processor data
c-user/symmetric_multiprocessing_services.rst | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/c-user/symmetric_multiprocessing_services.rst b/c-user/symmetric_multiprocessing_services.rst
index 638292b..b2773e7 100644
@@ -791,3 +791,21 @@ from the executing to the heir thread neither the stack of the executing nor
the heir thread must be used during interrupt processing. For this purpose a
temporary per-processor stack is set up which may be used by the interrupt
prologue before the stack is switched to the interrupt stack.
+RTEMS provides two means for per-processor data:
+1. Per-processor data which is used by RTEMS itself is contained in the
+ `Per_CPU_Control` structure. The application configuration via
+ `<rtems/confdefs.h>` creates a table of these structures
+ (`_Per_CPU_Information`). The table is dimensioned according to the count
+ of configured processors
+ (:ref:`CONFIGURE_MAXIMUM_PROCESSORS <CONFIGURE_MAXIMUM_PROCESSORS>`).
+2. For low level support libraries an API for statically allocated
+ per-processor data is available via
+ `<rtems/score/percpudata.h> <https://git.rtems.org/rtems/tree/cpukit/include/rtems/score/percpudata.h>`_.
+ This API is not intended for general application use. Please ask on the
+ development mailing list in case you want to use it.
More information about the vc