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code review from Josh and Robert


  15      vmem_create(const char *name, void *base, size_t size, size_t quantum,
  16          vmem_alloc_t *afunc, vmem_free_t *ffunc, vmem_t *source,
  17          size_t qcache_max, int vmflag);
  18 
  19      vmem_t *
  20      vmem_xcreate(const char *name, void *base, size_t size, size_t quantum,
  21          vmem_ximport_t *afunc, vmem_free_t *ffunc, vmem_t *source,
  22          size_t qcache_max, int vmflag);
  23 
  24      void
  25      vmem_destroy(vmem_t *vmp);
  26 
  27 INTERFACE LEVEL
  28      illumos DDI specific
  29 
  30 PARAMETERS
  31      name    A character string giving a name to the vmem arena to be created.
  32 
  33      base    An address indicating the lowest possible value in the arena.
  34 
  35      size    The size of the arena to create
  36 
  37      quantum
  38              The arena's ``quantum''.  The granularity of the arena.  The
  39              amount allocated at minimum by each request.

  40 
  41      afunc   A function which is called to import new spans from source.
  42              Which may be NULL if this arena does not import from another.



  43 
  44      ffunc   A function which is called to return spans to source.  Which may
  45              be NULL if this arena does not import from another.

  46 
  47      source  An arena from which this arena will import.  Which may be NULL if































  48              this arena does not import from another.
  49 
  50      qcache_max
  51              Each arena offers caching of integer multiples of quantum up to
  52              qcache_max.
  53 
  54      vmflag  A bitmask of flags indicating the characteristics of this arena.
  55 
  56              VMC_IDENTIFIER
  57                      The arena represents arbitrary integer identifiers,
  58                      rather than virtual memory.
  59 
  60      vmp     A pointer to the vmem arena to be destroyed.
  61 
  62 DESCRIPTION
  63      A vmem arena is a section of an arbitrary address space (a range of
  64      integer addresses).  This commonly represents virtual memory, but can in
  65      fact be an arbitrary set of integers. The VMC_IDENTIFIER flag set at
  66      arena creation time differentiates between these two cases.
  67 
  68      The afunc, ffunc, and source arguments combine to support a hierarchical
  69      structure of arenas, each importing from a single parent (the source).
  70      The vmem_create() and vmem_xcreate() functions differ in that the latter
  71      provides an interface for afunc to alter the size of the span imported
  72      from source.  It is only legal to increase thise size.
  73 
  74 CONTEXT
  75      These functions can be called from user or kernel context.
  76 
  77 RETURN VALUES
  78      Upon successful completion the vmem_create(and) vmem_xcreate() functions
  79      return a pointer to a vmem arena.  Otherwise, NULL is returned to
  80      indicate the arena could not be created.
  81 
  82 SEE ALSO
  83      vmem(9), vmem_add(9F), vmem_alloc(9F)
  84 
  85 illumos                        January 18, 2017                        illumos


  15      vmem_create(const char *name, void *base, size_t size, size_t quantum,
  16          vmem_alloc_t *afunc, vmem_free_t *ffunc, vmem_t *source,
  17          size_t qcache_max, int vmflag);
  18 
  19      vmem_t *
  20      vmem_xcreate(const char *name, void *base, size_t size, size_t quantum,
  21          vmem_ximport_t *afunc, vmem_free_t *ffunc, vmem_t *source,
  22          size_t qcache_max, int vmflag);
  23 
  24      void
  25      vmem_destroy(vmem_t *vmp);
  26 
  27 INTERFACE LEVEL
  28      illumos DDI specific
  29 
  30 PARAMETERS
  31      name    A character string giving a name to the vmem arena to be created.
  32 
  33      base    An address indicating the lowest possible value in the arena.
  34 
  35      size    The size of the arena to create.
  36 
  37      quantum
  38              The arena's ``quantum''.  The granularity of the arena.  The
  39              amount allocated at minimum by each request.  Must be a power of
  40              2.
  41 
  42      afunc   A function which is called to import new spans from source, which
  43              may be NULL if this arena does not import from another.  When
  44              calling vmem_create() afunc is an vmem_alloc_t a function taking
  45              three parameters and returning a pointer to void (the imported
  46              space):
  47 
  48              vmem_t *
  49                      The source arena from which we'll import.  The source
  50                      argument to vmem_create().
  51 
  52              size_t  The size to import
  53 
  54              int     The vmflag argument used for the import.
  55 
  56              When calling vmem_xcreate() afunc is an vmem_ximport_t a function
  57              taking four parameters and returning a pointer to void (the
  58              imported space):
  59 
  60              vmem_t *
  61                      The source arena from which we'll import.  The source
  62                      argument to vmem_xcreate().
  63 
  64              size_t *
  65                      The size of the import, afunc may increase this size if
  66                      that is desirable, but must never decrease it.
  67 
  68              size_t  The desired alignment of the imported space.
  69 
  70              int     the vmflag argument used for the import.
  71 
  72      ffunc   A function which is called to return spans to source, which may
  73              be NULL if this arena does not import from another.  This is a
  74              vmem_free_t a function taking three parametes and returning void:
  75 
  76              vmem_t  The arena to which space is being returned.  The source
  77                      argument to vmem_create() or vmem_xcreate().
  78 
  79              void *  The span being returned to the source arena.
  80 
  81              size_t  The size of the span being returned to the source arena.
  82 
  83      source  An arena from which this arena will import, which may be NULL if
  84              this arena does not import from another.
  85 
  86      qcache_max
  87              Each arena offers caching of integer multiples of quantum up to
  88              qcache_max, which may be 0.
  89 
  90      vmflag  A bitmask of flags indicating the characteristics of this arena.
  91 
  92              VMC_IDENTIFIER
  93                      The arena represents arbitrary integer identifiers,
  94                      rather than virtual memory.
  95 
  96      vmp     A pointer to the vmem arena to be destroyed.
  97 
  98 DESCRIPTION
  99      A vmem arena is a section of an arbitrary address space (a range of
 100      integer addresses).  This commonly represents virtual memory, but can in
 101      fact be an arbitrary set of integers. The VMC_IDENTIFIER flag set at
 102      arena creation time differentiates between these two cases.
 103 
 104      The afunc, ffunc, and source arguments combine to support a hierarchical
 105      structure of arenas, each importing from a single parent (the source).
 106      The vmem_create() and vmem_xcreate() functions differ in that the latter
 107      provides an interface for afunc to alter the size of the span imported
 108      from source.  It is only legal to increase this size.
 109 
 110 CONTEXT
 111      These functions can be called from user or kernel context.
 112 
 113 RETURN VALUES
 114      Upon successful completion the vmem_create() and vmem_xcreate() functions
 115      return a pointer to a vmem arena.  Otherwise, NULL is returned to
 116      indicate the arena could not be created.
 117 
 118 SEE ALSO
 119      vmem(9), vmem_add(9F), vmem_alloc(9F)
 120 
 121 illumos                        January 18, 2017                        illumos