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PVM Command


Commands to facilitate distributed computing using PVM . These commands are available from the PVM master program. See the appropriate sections for information on how to configure and run distributed Sabrina.

PVM with no arguments gives a list of available PVM options.

PVM { ADd | DElete }

ADD or DELETE one or more computers specified in to the PVM configuration, as in

pvm add duvall dansen nimoy

PVM BArs [ ON | OFf ]

When the Bars mode is ON, a bar code along the left side of the graphics window shows which slave computed each band in the picture. The codes give an indication of whether the work is being shared equally or if one or a few computers dominate. The current setting is reported if no argument is present.


CONF List machines in current configuration
PS Display UNIX task IDs of processes in use
STATS List timing and work statistics for each slave, including how many bands were contributed by each computer and their time per band. For Unix computers, both processing and system times are given.

PVM HOstfile filename

Set the PVM host file. The file contains a list of hosts that Sabrina will add to the PVM configuration when Sabrina starts PVM. The file is not used if PVM is already running when Sabrina starts.

PVM LOopdelay N

Set the Loop Delay to N milliseconds. The master and distributor processes continuously check for data and messages from the slaves while picture is being made. This polling can take a significant amount of time, especially on fast computers. If a query found no message waiting, the processes wait for N milliseconds before querying again. N must be less than 1 second and greater than or equal to 1 millisecond. The optimum value depends on the PVM configuration and the complexity of the picture.


Set the Slaves on Unix computers will be run with a nice value of N. N should be between 1 (high priority) and 20 (low priority). The value has no effect on slaves run on Windows computers.

PVM { ON | OFf }

Set the ON enables the PVM mode in which Sabrina runs on multiple computers. OFF disables the mode and Sabrina wil execute on only the local computer.

PVM WIth [ ON | OFf ]

Set the When ON, a slave process will run on the master computer. The master computer is usually the local computer. The slave processes perform the ray tracing calculations. Because the slave process competes with the master's work of displaying the grpahics, the advantage of running the slave on the master's processor depends on the relative speed of the computers in the configuration. The current setting is reported if no argument is present.