psort

OS/161 Reference Manual

Name

psort - concurrent file system test

Synopsis

/testbin/psort [-p numprocs] [-k numkeys] [-r | -s randomseed]

Description

psort does an on-disk parallelizing sort of a large number of randomly generated integers. It is loosely based on some real parallel sort benchmarks.

Be aware of its size vs. the size of your buffer cache, and adjust its size as needed. Running it so it fits entirely in cache and running it so it overflows the cache are both valid stress tests, but have quite different characteristics.

Options

• -k Set the number of integers. Default (for now) is 10000.
• -p Set the number of processes. Default is 4.
• -r Get a random seed from the random: device.
• -s randomseed Choose an explicit random seed.

The basic workload size is the number of integers multiplied by the byte size of an integer (here 4). The total size including intermediate files is two or three times that.

Requirements

psort uses the following system calls:

• open
• dup2
• read
• write
• lseek
• close
• stat or fstat (optional)
• remove
• fork
• execv
• waitpid
• _exit

psort should be able to run properly on SFS filesystems once the basic system calls are implemented. However, you may need to adjust its workload size depending on the level of large-file support you have in SFS.

psort will mostly run on emufs, but there isn't really much point in that.