nsg_attach_pid(3)

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nsg_attach_pid(3)
NAME
  nsg_attach_pid, nsg_detach_pid - Attaches a process to, or detaches a
  process from a NUMA Scheduling Group (libnuma library)

SYNOPSIS
  #include <numa.h>

  int nsg_attach_pid(
	  nsgid_t nsg,
	  pid_t pid,
	  ulong_t flags );

  int nsg_detach_pid(
	  pid_t pid );

PARAMETERS
  nsg Specifies the NUMA Scheduling Group (NSG) to which the listed process
      will be attached.

  pid Specifies the process ID to attach to (or detach from) the NSG.

  flags
      Specifies a bit mask of options that affect the attachment. The
      following options are defined for the flags argument:

      NSG_INSIST
	      The requested attachment and any implied reassignment is
	      mandatory, overriding any prior attachment and/or binding of
	      the specified processes.

      NSG_MIGRATE
	      Arrange for existing memory of the process that is assigned a
	      new home RAD to be migrated to the new RAD. If this option is
	      omitted, only newly allocated pages will be allocated on the
	      new home RAD. Existing pages will migrate if or when they
	      experience a high rate of remote cache misses. Migration will
	      occur only for pages in memory objects that have inherited the
	      process's default memory allocation policy.

      NSG_NO_INHERIT
	      A child process will not inherit the NSG of the parent and,
	      therefore, can be assigned to any eligible RAD on the system.

      NSG_WAIT
	      Wait for the requested memory migration to be completed, if
	      possible. If insufficient resources exist to satisfy the
	      request, the function will return without having completed the
	      migration. If NSG_INSIST is also specified, memory not migrated
	      will be paged out.

      See DESCRIPTION for more detail about these options.

DESCRIPTION
  The nsg_attach_pid() function attaches the process identified by the pid
  argument to an NSG. An NSG is a set of processes and/or threads that will
  be constrained to reside on the same Resource Affinity Domain (RAD). That
  is, the "home RAD" for all of the processes or threads in an NSG will be
  the same, and the entire group will be migrated together, if at all. The
  process identified by pid will be removed from any NSG of which it might
  currently be a member, before adding it to the specified NSG.

  If the pid argument is NULL, then the call is self-directed. That is, the
  function behaves as if the current process ID were specified.

  The nsg_detach_pid() will remove pid from its current NSG, if any, and will
  not add pid to any new NSG. It is equivalent to the nsg_attach_pid()
  function with the nsg argument of NSG_NONE.

RESTRICTIONS
  The caller must have partition administration privilege and the process
  identified by pid must be in the caller's partition.

RETURN VALUES
  0   Success. In this case, the nsg_attach_pid() function successfully
      attached to the NSG specified by nsg.

  0   Success. In this case, the nsg_detach_pid() function successfully
      detached from its NSG.

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

ERRORS
  If the nsg_attach_pid() function fails, it sets errno to one of the
  following values for the condition specified:

  [EACCES]
      The caller does not have execute permission required to attach
      processes to the NSG.

  [ESRCH]
      The process specified by pid does not exist.

  [EINVAL]
      The nsg argument does not specify a valid NSG, or one or more options
      in the flags argument are invalid.

  [EBUSY]
      The specified process is hard attached (RAD_INSIST) to RADs or has
      memory wired (locked) on its current RAD such that the process cannot
      be migrated to the RAD selected for the NSG.

  [ENOMEM]
      The NSG_INSIST and NSG_MIGRATE options were specified and no RAD can be
      found with sufficient memory to accommodate the resulting group.

  [EPERM]
      The real or effective user ID of the caller does not match the real or
      effective user ID of the process specified in pid.

  If the nsg_detach_pid() function fails, it sets errno to one of the
  following values for the condition specified:

  [EACCES]
      The caller does not have execute permission, which is required to
      detach processes from the NSG.

  [ESRCH]
      The process specified by pid does not exist.

  [EINVAL]
      The process specified by pid is not a member of an NSG.

  [EBUSY]
      The specified process is hard attached (RAD_INSIST) to RADs or has
      memory wired (locked) on its current RAD such that the process cannot
      be detached.

  [EPERM]
      The real or effective user ID of the caller does not match the real or
      effective user ID of the process specified in pid.

SEE ALSO
  Functions: nsg_init(3), numa_intro(3), pthread_nsg_attach(3)

  Files: numa_types(4)
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