BSP parameters(3)

NAME
bsp_l, bsp_g, bsp_s, bsp_nhalf - query the BSP's machine parameters

C SYNOPSIS
#include "bsp_level1.h"

double bsp_s();
double bsp_l();
double bsp_g();
int    bsp_nhalf();

FORTRAN SYNOPSIS
DOUBLE PRECISION FUNCTION bsps()
DOUBLE PRECISION FUNCTION bspl()
DOUBLE PRECISION FUNCTION bspg()
INTEGER          FUNCTION bspnhalf()

DESCRIPTION
These function return the BSP parameters for a machine:

bsp_s
    is the speed of computation of a process in flop/s (that is number of floating point operations per second).

bsp_l
    is the synchronisation latency cost in units of bsp_s . i.e., if s=1000 , then each processor of the machine could have performed 1000 floating point operations in the same time as all processors take to barrier synchronise.

bsp_g
    is the asymptotic number of flops/word required for all processors to simultaneously communicate a message.

bsp_nhalf
    is the number of words required to be communicated such that the communication performance deteriorates to 2g

In the current implementation of the library, the values for each of these parameters is read from a database file, and not calculated by experimentation at runtime.

FILES
The file PREFIX/include/bsp_parameters.ascii contains a table of the BSP parameters read by these functions; where PREFIX is the installation prefix set when configuring BSPlib.

SEE ALSO
bspparam(1), bsplib_level1(3)

BUGS
Problems and bug reports should be mailed to bsplib-bugs@comlab.ox.ac.uk

AUTHORS
Jonathan.Hill@comlab.ox.ac.uk
http://www.comlab.ox.ac.uk/oucl/people/jonathan.hill.html