NAME    [Toc]    [Back]

       pthread_nsg_attach  - Attaches a thread to a NUMA Scheduling
 Group (libpthread library)

SYNOPSIS    [Toc]    [Back]

       #include <numa.h>

       int pthread_nsg_attach(
               nsgid_t nsg,
               pthread_t thread,
               long flags );

PARAMETERS    [Toc]    [Back]

       Specifies the NUMA Scheduling Group  (NSG)  to  which  the
       thread  will  belong.   Identifies the thread to attach to
       the NSG.  Specifies options (bit  mask)  that  affect  the
       attachment. See DESCRIPTION for details.

DESCRIPTION    [Toc]    [Back]

       The  pthread_nsg_attach()  function  attaches  the  thread
       specified by the thread  argument  to  a  NUMA  Scheduling
       Group (NSG) specified by the nsg argument. 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/threads in  an
       NSG  will  be  the  same,  and  the  entire  group will be
       migrated together, if at  all.  The  thread  specified  by
       thread will be removed from any NSG of which it might currently
 be a member, before being added  to  the  specified
       NSG.

       If  the  specified  thread resides on a different RAD, the
       thread will be reassigned to a single RAD.  The  home  RAD
       for  the thread will be selected as follows: If the specified
 NSG already has processes/threads attached, the  home
       RAD for the specified thread will be the home RAD for that
       NSG.  If the specified NSG is empty, the home RAD for  the
       thread  will be selected based on the setting of the flags
       argument.

       The following options are defined for the flags  argument:
       The requested attachment and any implied reassignments are
       mandatory, overriding any prior binding of  the  specified
       thread. If this option is not set, and the thread is bound
       (RAD_INSIST) to a different RAD such that the system  cannot
  honor the request, the request will fail.  The thread
       has small memory requirements, so the system should  favor
       (for  the home RAD) those RADs with light CPU loads, independent
 of their available memory. This flag applies  only
       when attaching to an empty NSG.  The thread has large memory
 requirements, so the system should favor (for the home
       RAD) those RADs with more available memory, independent of
       their CPU loads. This flag only applies when attaching  to
       an  empty  NSG.   Arrange  for  the existing memory (stack
       pages) of a thread that is assigned a new home RAD  to  be
       migrated  to the new RAD. If omitted, only newly allocated
       pages will be allocated on  the  new  home  RAD.  Existing
       pages  will migrate if/when they experience a high rate of
       remote cache misses. Migration will occur only for  pagesin-memory
   objects  that  have  inherited  the  process's
       default memory allocation policy.  Wait for the  requested
       memory  migration  to be completed. Effectively, this flag
       specifies "migrate now!".

RETURN VALUES    [Toc]    [Back]

       Success.  Failure. In  this  case,  the  returned  integer
       indicates  the  type of error. Possible errors include the
       following: The caller does  not  have  execute  permission
       required  to  attach the thread based on the NSG's permissions.
  The thread specified by thread  is  hard  attached
       (RAD_INSIST)  to  RADs or has memory wired (locked) on its
       current RAD such that it cannot be migrated to the  common
       RAD selected for the NSG.  The value of the flags argument
       is invalid.  NSG_INSIST and NSG_MIGRATE were specified and
       no  RAD can be found with sufficient memory to accommodate
       the resulting group.  The thread specified by  the  thread
       argument does not exist.

ERRORS    [Toc]    [Back]

       None.

SEE ALSO    [Toc]    [Back]

       Functions: nsg_attach_pid(3), nsg_get(3), numa_intro(3)

       Files: numa_types(4)



                                            pthread_nsg_attach(3)