NAME

       memkind_arena - jemalloc arena allocation memkind operations.
       Note:  This  is  EXPERIMENTAL  API.  The  functionality  and the header file itself can be
       changed (including non-backward compatible changes) or removed.

SYNOPSIS

       int memkind_arena_create(struct memkind *kind, struct memkind_ops *ops, const char *name);
       int   memkind_arena_create_map(struct   memkind   *kind,   extent_hooks_t   *hooks);   int
       memkind_arena_destroy(struct memkind  *kind);  void  *memkind_arena_malloc(struct  memkind
       *kind,  size_t  size); void *memkind_arena_calloc(struct memkind *kind, size_t num, size_t
       size);  int  memkind_arena_posix_memalign(struct  memkind  *kind,  void  **memptr,  size_t
       alignment,  size_t  size);  void  *memkind_arena_realloc(struct  memkind *kind, void *ptr,
       size_t size); void *memkind_arena_realloc_with_kind_detect(void *ptr,  size_t  size);  int
       memkind_thread_get_arena(struct  memkind  *kind,  unsigned  int  *arena, size_t size); int
       memkind_bijective_get_arena(struct memkind  *kind,  unsigned  int  *arena,  size_t  size);
       struct      memkind     *get_kind_by_arena(unsigned     arena_ind);     struct     memkind
       *memkind_arena_detect_kind(void *ptr); int memkind_arena_finalize(struct  memkind  *kind);
       void  memkind_arena_init(struct  memkind  *kind);  void  memkind_arena_free(struct memkind
       *kind,   void   *ptr);   void   memkind_arena_free_with_kind_detect(void   *ptr);   size_t
       memkind_arena_malloc_usable_size(void                      *ptr);                      int
       memkind_arena_update_memory_usage_policy(struct  memkind  *kind,  memkind_mem_usage_policy
       policy); int memkind_arena_enable_background_threads(size_t threads_limit);

DESCRIPTION

       This  header  file  is  a  collection  of  functions  can  be used to populate the memkind
       operations structure for memory kinds that use jemalloc.

       memkind_arena_create() is an implementation of the memkind "create" operation  for  memory
       kinds  that  use  jemalloc.   This calls memkind_default_create() (see memkind_default(3))
       followed by memkind_arena_create_map() described below.

       memkind_arena_create_map() creates the arena_map array for the memkind  structure  pointed
       to  by  kind  which  can  be  indexed  by  the  ops.get_arena()  function  from the kind's
       operations.  If get_arena points memkind_thread_get_arena() then there will be four arenas
       created  for each processor, and if get_arena points to memkind_bijective_get_arena() then
       just one arena is created.

       memkind_arena_destroy() is an implementation of the memkind "destroy" operation for memory
       kinds   that   use   jemalloc.    This   releases   all  of  the  resources  allocated  by
       memkind_arena_create().

       memkind_arena_malloc() is an implementation of the memkind "malloc" operation  for  memory
       kinds   that   use   jemalloc.    This  allocates  memory  using  the  arenas  created  by
       memkind_arena_create() through the jemalloc's mallocx() interface.  It  uses  the  memkind
       "get_arena" operation to select the arena.

       memkind_arena_calloc()  is  an implementation of the memkind "calloc" operation for memory
       kinds  that  use  jemalloc.   This  allocates  memory  using   the   arenas   created   by
       memkind_arena_create()  through  the  jemalloc's mallocx() interface.  It uses the memkind
       "get_arena" operation to select the arena.

       memkind_arena_posix_memalign()  is  an  implementation  of  the  memkind  "posix_memalign"
       operation  for  memory  kinds  that  use jemalloc.  This allocates memory using the arenas
       created by memkind_arena_create() through the jemalloc's mallocx() interface.  It uses the
       memkind  "get_arena"  operation  to  select  the  arena.  The POSIX standard requires that
       posix_memalign(3) may not set errno however the jemalloc's mallocx() routine may.   In  an
       attempt to abide by the standard errno is recorded before calling jemalloc's mallocx() and
       then reset after the call.

       memkind_arena_realloc() is an implementation of the memkind "realloc" operation for memory
       kinds   that   use   jemalloc.    This  allocates  memory  using  the  arenas  created  by
       memkind_arena_create() through the jemalloc's mallocx() interface.  It  uses  the  memkind
       "get_arena" operation to select the arena.

       memkind_arena_realloc_with_kind_detect()  function will look up for kind associated to the
       allocated   memory   referenced   by   ptr   and   call   (depending   on   kind    value)
       memkind_arena_realloc() or memkind_default_realloc().

       memkind_thread_get_arena()  retrieves  the  arena  index  that  is bound to to the calling
       thread based on a hash  of  its  thread  ID.   The  arena  index  can  be  used  with  the
       MALLOCX_ARENA macro to set flags for jemalloc's mallocx().

       memkind_bijective_arena_get_arena()  retrieves  the  arena  index  to  be  used  with  the
       MALLOCX_ARENA macro to set flags for jemalloc's mallocx().  Use of this operation  implies
       that only one arena is used for the kind.

       memkind_arena_free() is an implementation of the memkind "free" operation for memory kinds
       that use jemalloc.  It causes the allocated memory referenced by ptr, which must have been
       returned   by   a  previous  call  to  memkind_arena_malloc(),  memkind_arena_calloc()  or
       memkind_arena_realloc() to be made available for future allocations.  It uses the  memkind
       "get_arena" operation to select the arena.

       memkind_arena_free_with_kind_detect()  function  will  look  up for kind associated to the
       allocated memory referenced by ptr and call memkind_arena_free().

       memkind_arena_detect_kind() returns pointer to memory kind structure associated with given
       allocated memory referenced by ptr.

       get_kind_by_arena() returns pointer to memory kind structure associated with given arena.

       memkind_arena_malloc_usable_size()  is  an  implementation  of  the  memkind "usable_size"
       operation for memory kinds that use jemalloc.

       memkind_arena_finalize() is an implementation of  the  memkind  "finalize"  operation  for
       memory  kinds  that  use  jemalloc.  This  function  releases  all  resources allocated by
       memkind_arena_create() and it's called  when  main()  finishes  or  after  calling  exit()
       function.

       memkind_arena_init() creates arena map with proper hooks per specified kind.

       memkind_arena_update_memory_usage_policy() function changes time, which determine how fast
       jemalloc returns unused pages back to the operating system, in other  words  how  fast  it
       deallocates file space.

       memkind_arena_enable_background_threads()  enables  internal  background worker threads in
       jemalloc.  The threads_limit specify limit of background threads which will be enabled ( 0
       means no limit).

COPYRIGHT

       Copyright (C) 2014 - 2019 Intel Corporation. All rights reserved.

SEE ALSO

       memkind(3),   memkind_default(3),   memkind_hbw(3),  memkind_hugetlb(3),  memkind_pmem(3),
       jemalloc(3), mbind(2), mmap(2)