shmx(8)shmx(8)Nameshmx - shared memory exerciser
Syntax
/usr/field/shmx [ -h ] [ -ofile ] [ -ti ] [ -mj ] [ -sk ] [ -v ]
Description
The memory exerciser spawns a background process and these two pro‐
cesses exercise the shared memory segments. They each take turns writ‐
ing and reading the other's data in the segments.
You can specify the number of memory segments to test and the size of
the segment to be tested by and processes. The exerciser runs until the
process receives a or a kill -15 pid.
A logfile is made in for you to examine and then remove. If there are
errors in the logfile, check the file, where the driver and kernel
error messages are saved. The exerciser is automatically invoked when
the exerciser is started. You can also run by itself.
Options-h Print the help message for the command.
-v Use the system call instead of to spawn
-ofile Save diagnostic output in file.
-ti Run time in minutes (i). The default is to run until the
process receives a or a kill -15 pid.
-mj The memory segment size in bytes (j) to be tested by the pro‐
cesses. Must be greater than 0. The default is SMMAX/6.
(SMMAX is a system parameter set in the file
-sk The number of memory segments (k). The default is 6. The
maximum is also 6.
Examples
The following example tests six memory segments (default), each with a
segment size of SMMAX/6, until a or kill -15 pid is received:
% /usr/field/shmx
The following example runs three memory segments of size 100,000 bytes
for 180 minutes in the background:
% /usr/field/shmx -t180 -m100000 -s3 &
Restrictions
If there is a 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 the target file system must be
writable by root. Also the directory, in which any of 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.
See Also
Guide to System Exercisers
shmx(8)
