From: "Omar G. Stradella" Newsgroups: comp.parallel Subject: Re: Origin2000 Shared Memory Date: 14 May 1999 05:58:14 GMT Organization: Silicon Graphics, Inc. Approved: bigrigg@cs.cmu.edu Message-Id: <7hge1m$lp6$1@goldenapple.srv.cs.cmu.edu> Originator: bigrigg@ux6.sp.cs.cmu.edu Xref: ukc comp.parallel:15600 Randy Crawford wrote: > NUM_THREADS > Not a standard Irix environment variable. Often used by pthread > programmers. However, Irix tools do not recognize this variable. Not true. NUM_THREADS is recognized by the IRIX MP library. > OMP_NUM_THREADS > Used by OpenMP binaries only (C or Fortran). Partially true, see below. > MPC_NUM_THREADS > Should be MPC_SET_NUMTHREADS. Used by the Irix MP multithreading > library, for Power C/Fortran and their shared-memory parallel > directives (like $do_across). In practice all these are equivalent and you can use any of them to specify the number of processes to be created for a program containing parallel directives (either the traditional ones like DOACROSS or the new ones from OpenMP). But, if you set more than one, there is a precedence order that is: OMP_NUM_THREADS takes precedence over MP_SET_NUMTHREADS, which takes precedence over MPC_NUM_THREADS, which takes precedence over NUM_THREADS. Omar. -- +---------------------------------------------------------------------+ Omar G. Stradella, Ph.D. SGI / Chemistry and Biology Applications Group One Cabot Road, Hudson, MA 01749, USA N 42 22'40" W 71 33'44" E-mail: omar@boston.sgi.com Phone: +1-978-567-2258 FAX: +1-978-562-4755 http://www.sgi.com/chembio http://reality.sgi.com/omar +-------- Ph-nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn -------+ -- Articles to bigrigg+parallel@cs.cmu.edu (Admin: bigrigg@cs.cmu.edu) Archive: http://www.hensa.ac.uk/parallel/internet/usenet/comp.parallel