[PATCH 1/3] score: Remove _Stack_Adjust_size()

[sebastian.huber at embedded-brains.de]

From: Sebastian Huber <sebastian.huber at embedded-brains.de>

The increase of the stack size by CPU_STACK_ALIGNMENT in
_Thread_Stack_Allocate() is disadvantageous.  This may lead to a huge
over allocation for specialized stack allocators.  The
CPU_STACK_ALIGNMENT is at most 16 on all current RTEMS CPU ports.  The
mimimum stack size ensured by _Stack_Ensure_minimum() must be
considerable larger than this value, otherwise stack overflows will
likely occur.  Thus the _Stack_Adjust_size() is also superfluous.
---
 cpukit/score/inline/rtems/score/stack.inl |   18 ------------------
 cpukit/score/src/threadstackallocate.c    |   12 ------------
 2 files changed, 0 insertions(+), 30 deletions(-)

diff --git a/cpukit/score/inline/rtems/score/stack.inl b/cpukit/score/inline/rtems/score/stack.inl
index c5d809c..2f49d01 100644
--- a/cpukit/score/inline/rtems/score/stack.inl
+++ b/cpukit/score/inline/rtems/score/stack.inl
@@ -24,7 +24,6 @@
 #define _RTEMS_SCORE_STACK_INL
 
 #include <rtems/score/basedefs.h> /* RTEMS_INLINE_ROUTINE */
-#include <rtems/score/cpu.h> /* CPU_STACK_ALIGNMENT */
 
 /**
  *  @addtogroup ScoreStack 
@@ -90,23 +89,6 @@ RTEMS_INLINE_ROUTINE size_t _Stack_Ensure_minimum (
   return _Stack_Minimum();
 }
 
-/**
- *  This function increases the stack size to ensure that the thread
- *  has the desired amount of stack space after the initial stack
- *  pointer is determined based on alignment restrictions.
- *
- *  @note
- *
- *  The amount of adjustment for alignment is CPU dependent.
- */
-
-RTEMS_INLINE_ROUTINE uint32_t   _Stack_Adjust_size (
-  size_t size
-)
-{
-  return size + CPU_STACK_ALIGNMENT;
-}
-
 /**@}*/
 
 #endif
diff --git a/cpukit/score/src/threadstackallocate.c b/cpukit/score/src/threadstackallocate.c
index 9448328..68aa649 100644
--- a/cpukit/score/src/threadstackallocate.c
+++ b/cpukit/score/src/threadstackallocate.c
@@ -51,18 +51,6 @@ size_t _Thread_Stack_Allocate(
 
   the_stack_size = _Stack_Ensure_minimum( stack_size );
 
-  /*
-   *  Pad the requested size so we allocate enough memory
-   *  so the context initialization can align it properly.  The address
-   *  returned the workspace allocate must be directly stored in the
-   *  stack control block because it is later used in the free sequence.
-   *
-   *  Thus it is the responsibility of the CPU dependent code to
-   *  get and keep the stack adjust factor, the stack alignment, and
-   *  the context initialization sequence in sync.
-   */
-  the_stack_size = _Stack_Adjust_size( the_stack_size );
-
   stack_addr = (*stack_allocate_hook)( the_stack_size );
 
   if ( !stack_addr )
-- 
1.7.1