shmx - shared memory exerciser
/usr/field/shmx [-h] [-ofile] [-ttime] [-msize] [-ssegment] [-v]
You can use the following options:
-h Prints the help message for the shmx command.
-v Uses the fork(2) system call instead of the vfork(2) call to spawn
Saves diagnostic output in file.
Specifies the run time in minutes. The default is to run until the
process is killed.
Specifies the memory segment size in bytes to be tested by the
processes. Must be greater than 0. The default is SHMMAX/SHMSEG.
(SHMMAX and SHMSEG are system parameters set in the
-sn Specifies the number of memory segments. The default and maximum
number is 3.
The shmx memory exerciser spawns the background process shmxb, and these
two processes exercise the shared memory segments. They alternate writing
and reading the other process' data in the segments.
You can specify the number of memory segments to test and the size of the
segment to be tested by shmx and shmxb processes. The shmx exerciser runs
until the process is killed.
A log file for you to examine and then remove is created in the current
working directory. If there are errors in the logfile, check the syslog
files where the driver and kernel error messages are saved. The shmx
exerciser is automatically invoked when the memx exerciser is started. You
can also invoke shmx manually.
If you need to run a system exerciser over an NFS link or on a diskless
system, there are some restrictions. For exercisers that need to write into
a file system, such as fsx(8), the target file system must be writable by
root. Also the directory from which the exercisers are executed must be
writable by root because temporary files are written into the current
directory. These latter restrictions are sometimes difficult to overcome
because often NFS file systems are mounted in a way that prevents root from
writing into them. Some of the restrictions may be overcome by copying the
exerciser to another directory and then executing it.
1. The following example tests the default number of memory segments (3),
each with the default segment size (SHMMAX/SHMSEG):
% /usr/field/shmx &&
2. The following example runs two memory segments of size 100,000 bytes
for 180 minutes:
% /usr/field/shmx -t180 -m100000 -s2 &&
Commands: cmx(8), diskx(8), fsx(8), memx(8), tapex(8)