.\" SCCSID: @(#)shmx.8	8.1	9/11/90.TH shmx 8 .SH Nameshmx \- shared memory exerciser.SH Syntax.B /usr/field/shmx[.B \-h] [.BI \-o file.B ] [.BI \-t i.B ] [.BI \-m j.B ] [.BI \-s k.B ] [.BI \-v.B ].SH Description.NXR "shmx exerciser".NXR "shared memory" "exercising"The .PN shmx memory exerciser spawns a backgroundprocess.PN shmxband these two processes exercise the shared memorysegments. They each take turns writing and readingthe other's data in the segments..PPYou can specify the number of memory segments to test and the size of the segment to be tested by  .PN shmxand.PN shmxbprocesses. The .PN shmxexerciserruns until the processreceives a.CT Cor a kill \-15 \fIpid\fR..PPA logfile is made in .PN /usr/fieldfor you to examine and then remove. If there are errorsin the logfile, check the .PN /usr/adm/syserr/syserr.<hostname> file, where the driver and kernel errormessages are saved.The .PN shmxexerciser is automatically invoked when the .PN memxexerciser is started.  You can also run .PN shmxby itself..SH Options.IP \fB\-h\fR 10Print the help message for the.PN shmxcommand..IP \fB\-v\fRUse the .MS fork 2system call instead of .MS vfork 2to spawn.PN shmxb ..IP \fB\-o\fIfile\fRSave diagnostic output in \fIfile\fR..IP \fB\-t\fIi\fRRun time in minutes (\|\fIi\fR\|).  The default is to run untilthe process receives a.CT C or a kill \-15 \fIpid\fR..IP \fB\-m\fIj\fRThe memory segment size in bytes (\|\fIj\fR\|) to be tested by theprocesses.  Must be greater than 0.  The default isSMMAX/6.  (SMMAX is a system parameter set in the file.PN sys/conf/param.c .) .IP \fB\-s\fIk\fRThe number of memory segments (\|\fIk\fR\|).  The default is 6.The maximum is also 6..SH ExamplesThe following example tests six memory segments (default),each with a segment size of SMMAX/6, until a.CT Cor kill \-15\fI pid\fR is received:.EX% /usr/field/shmx .EEThe following example runs three memory segments of size 100,000bytes for 180 minutes in the background:.EX% /usr/field/shmx \-t180 \-m100000 \-s3 &.EE.SH 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 .MS fsx 8 ,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 temporaryfiles 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 beovercome by copying the exerciser to another directory and then executing it.  .SH See Also.I Guide to System Exercisers