NAME

shmx − shared memory exerciser

SYNTAX

/usr/field/shmx [ −h ] [ −ofile ] [ −ti ] [ −mj ] [ −sk ] [ −v ]

DESCRIPTION

The shmx memory exerciser spawns a background process shmxb and these two processes exercise the shared memory segments. They each take turns writing 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 shmx and shmxb processes. The shmx exerciser runs until the process receives a <CTRLC> or a kill -15 pid. 

A logfile is made in /usr/field for you to examine and then remove. If there are errors in the logfile, check the /usr/adm/syserr/syserr.<hostname> file, where the driver and kernel error messages are saved. The shmx exerciser is automatically invoked when the memx exerciser is started.  You can also run shmx by itself.

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 fsx(,), 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.

OPTIONS

−hPrint the help message for the shmx command.

−vUse the fork() system call instead of vfork() to spawn shmxb.

−ofileSave diagnostic output in file. 

−tiRun time in minutes (i).  The default is to run until the process receives a <CTRLC> or a kill -15 pid. 

−mjThe memory segment size in bytes (j) to be tested by the processes.  Must be greater than 0.  The default is SMMAX/6.  (SMMAX is a system parameter set in the file sys/conf/param.c.)

−skThe 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 <CTRLC> 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 &

SEE ALSO

Guide to System Exercisers