tools/genload/README

USAGE

See the program's usage statement by invoking with --help.

NOTES

This program works really well for me, but it might not have some of the
features that you want.  If you would like, please extend the code and send
me the patch[1].  Enjoy the program :-)

Please use the context diff format.  That is: save the original program
as stress.c.orig, then make and test your desired changes to stress.c, then
run 'diff -u stress.c.orig stress.c' to produce a context patch.  Thanks.

Amos Waterland <apw@rossby.metr.ou.edu>
Norman, Oklahoma
27 Nov 2001

EXAMPLES
[examples]

The simple case is that you just want to bring the system load average up to
an arbitrary value.  The following forks 13 processes, each of which spins
in a tight loop calculating the sqrt() of a random number acquired with
rand().

  % stress -c 13

Long options are supported, as well as is making the output less verbose.
The following forks 1024 processes, and only reports error messages if any.

  % stress --quiet --hogcpu 1k

To see how your system performs when it is I/O bound, use the -i switch.
The following forks 4 processes, each of which spins in a tight loop calling
sync(), which is a system call that flushes memory buffers to disk.

  % stress -i 4

Multiple hogs may be combined on the same command line.  The following does
everything the preceding examples did in one command, but also turns up the
verbosity level as well as showing how to cause the command to
self-terminate after 1 minute.

  % stress -c 13 -i 4 --verbose --timeout 1m

An value of 0 normally denotes infinity.  The following is how to do a fork
bomb (be careful with this).

  % stress -c 0

For the -m and -d options, a value of 0 means to redo their operation an
infinite number of times.  To allocate and free 128MB in a redo loop use the
following command.  This can be useful for "bouncing" against the system RAM
ceiling.

  % stress -m 0 --hogvm-bytes 128M

For the -m and -d options, a negative value of n means to redo the operation
abs(n) times.  Here is now to allocate and free 5MB three times in a row.

  % stress -m -3 --hogvm-bytes 5m

You can write a file of arbitrary length to disk.  The file is created with
mkstemp() in the current directory, the default is to unlink it, but
unlinking can be overridden with the --hoghdd-noclean flag.

  % stress -d 1 --hoghdd-noclean --hoghdd-bytes 13

Large file support is enabled.

  % stress -d 1 --hoghdd-noclean --hoghdd-bytes 3G