Content-type: text/html Man page of shmx

shmx

Section: Maintenance Commands (8)
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NAME

shmx - shared memory exerciser  

SYNOPSIS

/usr/field/shmx [ -h ] [ -ofile ] [ -ttime ] [ -msize ] [ -ssegment ] [ -v ]  

DESCRIPTION

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.  

FLAGS

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 shmxb.
-ofile
Saves diagnostic output in file.
-ttime
Specifies the run time in minutes. The default is to run until the process is killed.
-msize
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 /sys/include/sys/param.h file.)
-sn
Specifies the number of memory segments. The default and maximum number is 3.
 

RESTRICTIONS

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.  

EXAMPLES

The following example tests the default number of memory segments (3), each with the default segment size (SHMMAX/SHMSEG): % /usr/field/shmx & The following example runs two memory segments of size 100,000 bytes for 180 minutes: % /usr/field/shmx -t180 -m100000 -s2 &  

RELATED INFORMATION

cmx(8), fsx(8), memx(8), tapex(8), diskx(8) delim off


 

Index

NAME
SYNOPSIS
DESCRIPTION
FLAGS
RESTRICTIONS
EXAMPLES
RELATED INFORMATION

This document was created by man2html, using the manual pages.
Time: 02:40:27 GMT, October 02, 2010