plucky (3) memkind_pmem.3.gz

NAME

       memkind_pmem - file-backed memory 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_pmem_create(struct memkind *kind, struct memkind_ops *ops, const char *name);
       int memkind_pmem_destroy(struct memkind *kind);
       void *memkind_pmem_mmap(struct memkind *kind, void *addr, size_t size);
       int memkind_pmem_get_mmap_flags(struct memkind *kind, int *flags);
       int memkind_pmem_validate_dir(const char *dir);

DESCRIPTION

       The pmem memory memkind operations enable memory kinds  built  on  memory-mapped  files.   These  support
       traditional  volatile  memory allocation in a fashion similar to libvmem(3) library.  It uses the mmap(2)
       system call to create a pool of volatile memory.  Such memory may have different attributes, depending on
       the file system containing the memory-mapped files.  (See also http://pmem.io/pmdk/libvmem).

       The pmem kinds are most useful when used with DAX (direct mapping of persistent memory), which is memory-
       addressable persistent storage that supports load/store access without being paged via  the  system  page
       cache.  A Persistent Memory-aware file system is typically used to provide this type of access.

       The    most    convenient   way   to   create   pmem   kinds   is   to   use   memkind_create_pmem()   or
       memkind_create_pmem_with_config() (see memkind(3)).

       memkind_pmem_create() is an implementation of the  memkind  "create"  operation  for  file-backed  memory
       kinds.   This  allocates  a space for some pmem-specific metadata, then calls memkind_arena_create() (see
       memkind_arena(3))

       memkind_pmem_destroy() is an implementation of the memkind "destroy"  operation  for  file-backed  memory
       kinds.   This releases all of the resources allocated by memkind_pmem_create() and allows the file system
       space to be reclaimed.

       memkind_pmem_mmap() allocates the file system space for a block of size bytes in the  memory-mapped  file
       associated  with given kind.  The addr hint is ignored.  The return value is the address of mapped memory
       region or MAP_FAILED in the case of an error.

       memkind_pmem_get_mmap_flags() sets flags to MAP_SHARED.  See mmap(2) for  more  information  about  these
       flags.

       memkind_pmem_validate_dir()  returns  zero  if  file  created  in specified pmem_dir supports DAX (direct
       mapping of persistent memory) or an error code from the ERRORS if not.

       MEMKIND_PMEM_CHUNK_SIZE
              The size of the PMEM chunk size.

COPYRIGHT

       Copyright (C) 2015 - 2020 Intel Corporation. All rights reserved.

SEE ALSO

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