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nshmget(3)
NAME
  nshmget - Returns (or creates) the ID for a shared memory region (libnuma
  library)

SYNOPSIS
  #include <numa.h>
  #include <sys/shm.h>

  int nshmget(
	  key_t key,
	  size_t size,
	  int shmflg,
	  memalloc_attr_t *attr );

PARAMETERS
  key Specifies the key that identifies the shared memory region. The value
      for the key parameter can be IPC_PRIVATE or a random number other than
      zero (0). If the value of key is IPC_PRIVATE, it can be used to assure
      the return of a new, unused shared memory region.

  size
      Specifies the minimum number of bytes to allocate for the region.

  shmflg
      Specifies the creation flags. See shmget(2) for a description of these
      flags.

  attr
      Points to a memory allocation policy and attributes structure. If the
      specified key does not exist, and a shared memory region is created,
      these attributes will be assigned to the memory object created to
      manage the shared memory region.

DESCRIPTION
  If the attr argument is NULL, the nshmget() function behaves identically to
  the shmget() function.

  If the attr argument is non-NULL, it points to a memory allocation policy
  and attributes structure that specifies where the pages should be allocated
  for a newly created shared memory region. To change the policy of an
  existing shared memory region, use the nmadvise() function.

  If the mattr_policy member of the structure pointed to by attr is
  MPOL_DIRECTED and the mattr_rad member is RAD_NONE, the system will choose
  the Resource Affinity Domain (RAD) where the pages of the shared memory
  region will be allocated from among the RADs specified in the mattr_radset
  member of *attr.  If the mattr_radset member is the empty set, the system
  will select a RAD for the memory object from among all of the RADs in the
  caller's partition, and the overflow set will be the empty set.

RETURN VALUES
  ID of a shared memory region
      Success.

  -1  Failure. In this case, errno is set to indicate the error.

ERRORS
  The nshmget() function returns errors for all the conditions that are
  documented for the shmget() function.	 In addition, the nshmget() function
  sets errno for the following:

  [EFAULT]
      A non-NULL attr argument points to an invalid address.

  [EINVAL]
      The structure pointed to by the attr argument contains an invalid
      memory allocation policy or an invalid RAD number. (The RAD number is
      less than 0 or greater than nrads.) This error can also occur if the
      memory allocation policy is MPOL_STRIPED, but the specified stride
      (stripe width) is 0 pages.

SEE ALSO
  Functions: shmget(2), nmadvise(3), numa_intro(3)

  Files: numa_types(4), shmid_ds(4)

Index for Section 3

Alphabetical listing for N

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