bionic (3) memkind_pmem.3.gz

NAME

       memkind_pmem.h - file-backed memory memkind operations.
       Note:  This  is  EXEPRIMENTAL API. The functionality and the header file itself can be changed (including
       non-backward compatible changes), or remove.

SYNOPSIS

       #include <memkind/internal/memkind_pmem.h>

       Link with -lmemkind

       int memkind_pmem_create(struct memkind *kind, const 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_get_size(struct memkind *kind, size_t *total, size_t *free);

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/nvml/libvmem).

       The pmem memkinds are most useful when used with Direct Access storage (DAX), 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 memkinds is to use memkind_create_pmem() (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_get_size() sets total to the number of bytes of the entire usable space in the memory-mapped
       file  associated  with  the  specified kind, and sets free to the number of unused bytes available in the
       memory-mapped file.

       MEMKIND_PMEM_MIN_SIZE
              The minimum size of the file-backed memory partition.

COPYRIGHT

       Copyright (C) 2015 - 2016 Intel Corporation. All rights reserved.

SEE ALSO

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