Table of Contents

Name

bw_mmap_rd - time the reading and summing of a file

Synopsis

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

Description

bw_mmap_rd creates a memory mapping to the file and then reads the mapping in an unrolled loop similar to that used in bw_mem_rd(8) . The benchmark is intended to be used on a file that is in memory, i.e., the benchmark is a reread benchmark. Other file benchmarking can be done with lmdd(8) .

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

Output

Output format is CB"%0.2f %.2f\n", megabytes, megabytes_per_second, i.e.,

8.00 25.33

Memory Utilization

This benchmark should move approximately the reported amount of memory.

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.


Table of Contents