Add some comments.

mm/mm_heap/mm_initialize.c

@@ -79,12 +79,12 @@ void mm_addregion(FAR struct mm_heap_s *heap, FAR void *heapstart,
 # define IDX 0
 #endif
 
+#if defined(CONFIG_MM_SMALL) && !defined(CONFIG_SMALL_MEMORY)
   /* If the MCU handles wide addresses but the memory manager is configured
    * for a small heap, then verify that the caller is  not doing something
    * crazy.
    */
 
-#if defined(CONFIG_MM_SMALL) && !defined(CONFIG_SMALL_MEMORY)
   DEBUGASSERT(heapsize <= MMSIZE_MAX+1);
 #endif
 

sched/semaphore/sem_post.c

@@ -98,7 +98,22 @@ int sem_post(FAR sem_t *sem)
 
       flags = enter_critical_section();
 
-      /* Perform the semaphore unlock operation. */
+      /* Perform the semaphore unlock operation, releasing this task as a
+       * holder then also incrementing the count on the semaphore.
+       *
+       * NOTE:  When semaphores are used for signaling purposes, the holder
+       * of the semaphore may not be this thread!  In this case,
+       * sem_releaseholder() will do nothing.
+       *
+       * In the case of a mutex this could be simply resolved since there is
+       * only one holder but for the case of counting semaphores, there may
+       * be many holders and if the holder is not this thread, then it is
+       * not possible to know which thread/holder should be released.
+       *
+       * For this reason, it is recommended that priority inheritance be
+       * disabled via sem_setprotocol(SEM_PRIO_NONE) when the semahore is
+       * initialixed if the semaphore is to used for signaling purposes.
+       */
 
       ASSERT(sem->semcount < SEM_VALUE_MAX);
       sem_releaseholder(sem);