DPLACE(3)							     DPLACE(3)

NAME    [Toc]    [Back]

     dplace_file, dplace_line, libdplace - a library interface to dplace

C SYNOPSIS    [Toc]    [Back]

	 void dplace_file( char	*filename);
	 void dplace_line( char	*line);



FORTRAN	SYNOPSIS
	  CHARACTER*n string
	  CALL dplace_file( string)
	  CALL dplace_line( string)

DESCRIPTION    [Toc]    [Back]

     These library routines provide high level access to a subset of the
     memory management and control mechanisms of IRIX. Dynamic dplace(1)
     functionality is provided from within a user's program.  The first	form
     takes a filename as an argument and all commands within the file are
     processed.	The second form	operates on a single command.  Errors are
     handled in	the same way as	dplace(1); the program exits and a diagnostic
     message is	printed	to standard error.  The	library	can be used with or
     without using dplace(1).


EXAMPLE	CODE
     Here is a fragment	of FORTRAN code

	     CHARACTER*128 s
	     np	= mp_numthreads()
	     WRITE(s,*)	'memories ',np,' in cube'
	     CALL dplace_line(s)

	     WRITE(s,*)	'threads ',np
	     CALL dplace_line(s)

	     DO	i=0, np-1
		 WRITE(s,*) 'run thread',i,' on	memory',i
		 CALL dplace_line(s)
		 head =	%loc( a( 1+i*(n/np) ) )
		 tail =	%loc( a( (i+1)*(n/np) )	)
		 WRITE(s,*) 'place range',head,' to',tail,' on memory',i
		 CALL dplace_line(s)
	     END DO

	     DO	i=0, np-1
		 WRITE(s,*) 'move thread',i,' to memory',np-1-i
		 CALL dplace_line(s)
	     END DO




									Page 1






DPLACE(3)							     DPLACE(3)



	     DO	i=0, np-1
		 head =	%loc( a( 1+i*(n/np) ) )
		 tail =	%loc( a( (i+1)*(n/np) )	)
		 WRITE(s,*) 'migrate range',head,' to',tail,' to memory',np-1-i
		 CALL dplace_line(s)
	     END DO


     and here is a C language code fragment:

	  main(){ /* C	example	code */
	  ...
	      dplace_file("initial_placement_file");
	  ...
	  ... data initialization,sprocs etc.
	  ...
	      for(i=0;i<nthreads;i++){
	       sprintf(cmd,"run	thread %d on memory %d\n",i,i/2);
	      dplace_line(cmd);
	  ...
	      sprintf(cmd,"migrate range %d to %d to memory %d\n"
	       ,&a[i*size],&a[(i+1)size-1],i/2);
	      dplace_line(cmd);
	  ...
	      }
	  }

     When linking C or FORTRAN programs, the flag -ldplace will	automatically
     invokes the correct libdplace library.

FILES    [Toc]    [Back]

     /usr/lib/libdplace.so

     /usr/lib64/libdplace.so

     /usr/lib32/libdplace.so

DEPENDENCIES    [Toc]    [Back]

     These procedures are only available on NUMA systems. In order to avoid
     conflicts with Fortran's libmp, it	is advisable to	set the	environment
     variable _DSM_OFF to disable libmp's NUMA functionality before running
     programs that are linked with libdplace.

BUGS    [Toc]    [Back]

     Operations	on the default policy module, such as the setting of default
     page sizes, should	be done	prior to an exec call to take effect. For
     example, setting the data page size with dplace_line or dplace_file from
     the program in question will not have the desired effect.





									Page 2






DPLACE(3)							     DPLACE(3)

SEE ALSO    [Toc]    [Back]

     dplace(1),	dplace(5)


									PPPPaaaaggggeeee 3333