NAME

       lat_mmap - costs of mmapping and unmmapping varying file sizes

SYNOPSIS

       lat_mmap [ -P <parallelism> ] [ -W <warmups> ] [ -N <repetitions> ] size file

DESCRIPTION

       lat_mmap  times how fast a mapping can be made and unmade.  This is useful because it is a
       fundamental part of processes that use SunOS style shared  libraries  (the  libraries  are
       mapped in at process start up time and unmapped at process exit).

       The  benchmark  maps in and unmaps the first size bytes of the file repeatedly and reports
       the average time for one mapping/unmapping.

       The size specification may end with ``k'' or ``m'' to mean kilobytes (* 1024) or megabytes
       (* 1024 * 1024).

OUTPUT

       Output format is "%0.2f %d\n", megabytes, usecs, i.e.,

       8.00 1200

ACKNOWLEDGEMENT

       Funding  for  the  development  of  this  tool  was  provided by Sun Microsystems Computer
       Corporation.

SEE ALSO

       lmbench(8).

AUTHOR

       Carl Staelin and Larry McVoy

       Comments, suggestions, and bug reports are always welcome.

(c)1994 Larry McVoy                           $Date$                                  LAT_MMAP(8)