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NAME    [Toc]    [Back]

       shmx - shared memory exerciser

SYNOPSIS    [Toc]    [Back]

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

OPTIONS    [Toc]    [Back]

       You can use the following options: Prints the help message
       for  the  shmx  command.   Uses  the  fork(2)  system call
       instead of the vfork(2) call to spawn shmxb.  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 </sys/include/sys/param.h>  file.)   Specifies  the
       number of memory segments.  The default and maximum number
       is 3.

DESCRIPTION    [Toc]    [Back]

       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

       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.

RESTRICTIONS    [Toc]    [Back]

       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    [Toc]    [Back]

       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 &

SEE ALSO    [Toc]    [Back]

       Commands: cmx(8), diskx(8), fsx(8), memx(8), tapex(8)

[ Back ]
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