[RTEMS Project] #4643: wkspace "failed allocations" increase with heap protection enabled

[RTEMS trac]

#4643: wkspace "failed allocations" increase with heap protection enabled
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  Reporter:  Matthew J Fletcher  |      Owner:  Sebastian Huber
      Type:  defect              |     Status:  assigned
  Priority:  low                 |  Milestone:
 Component:  score               |    Version:  5
  Severity:  normal              |   Keywords:
Blocked By:                      |   Blocking:
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 Investigating the "Total number of failed allocations:" from the wkspace
 cmd i see that;

     /* Statistics */
     ++stats->failed_allocs;

 Are incremented when _Heap_Allocate_aligned_with_boundary fails, however
 it seems this will routinely fail due to;

 _Heap_Protection_free_all_delayed_blocks seemingly on purpose creating an
 impossibly large allocation.

     uintptr_t large = 0
       - (uintptr_t) HEAP_BLOCK_HEADER_SIZE
       - (uintptr_t) HEAP_ALLOC_BONUS
       - (uintptr_t) 1;

     void *p = _Heap_Allocate( heap, large );

 This makes it difficult to place a breakpoint on failed_allocs to
 investigate true low memory situations with heap protection enabled.

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Ticket URL: <http://devel.rtems.org/ticket/4643>
RTEMS Project <http://www.rtems.org/>
RTEMS Project