CLSHMCTL(1M) CLSHMCTL(1M)
NAME
clshmctl - Administration tool for CrayLink Shared Memory
SYNOPSIS
clshmctl startup
clshmctl shutdown
clshmctl getcfg
clshmctl maxjobs <num of jobs>
clshmctl maxpgs <num of pages>
DESCRIPTION
clshmctl is a system-administrator's tool for controlling the resources
associated with CrayLink-shared-memory (clshm) -- a means of cache-
coherent, shared-memory communication between partitions on an Origin-
2000. Each partition of an Origin-2000 has its own hostname, IP address
and operating-system, and behaves as a stand-alone host. clshm is meant
for use by system libraries such as MPI, rather than directly by user-
applications.
clshmctl performs various functions needed to administer the software
devices and daemon associated with clshm and returns operational status
information.
clshmctl is invoked with one of the following function names, and the
associated parameters:
startup Configure clshm on the local partition, and start up the
clshm devices and clshm daemon (clshmd) with default
parameters. The value of the defaults can be examined by
using the clshmctl getcfg function, as explained later. The
startup step is performed at system boot-up by
/etc/init.d/clshm and is required before any inter-partition
communication can be effected over CrayLink Shared Memory. It
also needs to be done if clshm has been reset by a clshmctl
shutdown command. clshmctl startup also creates and
initializes the software devices through which shared-memory
communication is performed.
shutdown Forces a reset of the clshm software on the local partition.
The clshm daemon is made to exit, the resources associated
with the clshm software devices are released, and the devices
are removed from the hardware-graph filesystem. clshmctl
shutdown will fail if any user-program is using any of the
clshm devices when this function is called.
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CLSHMCTL(1M) CLSHMCTL(1M)
getcfg Returns the configuration of clshm on the local partition.
The parameters configurable through clshmctl are the maximum
number of independent channels of shared-memory communication
that are simultaneously supported (with a software device
corresponding to each channel), and the maximum number of
pages of shared-memory that are supported for each channel.
maxjobs <num of jobs>
Sets the maximum number of channels of cross-partition
shared-memory on the local partition. The number of jobs
specified must be at least 1. The software devices
corresponding to the channels are numbered 0, 1, ... <num of
jobs - 1>. maxjobs <num of jobs> will fail if it is called
after an open has been called on any of the software devices.
maxpgs <num of pages>
Sets the maximum number of pages of shared memory that can be
associated with any of the channels on the local partition.
maxpgs <num of pages> will fail if it is called after an open
has been called on any of the software devices.
WARNINGS
Device number 0 is reserved for querying the clshm software, and cannot
be used for regular inter-partition communication by any library that
uses clshm. Device number 0 cannot be opened O_EXCL.
SEE ALSO
clshm_diag(1m), clshmd (1m), mkpart(1m)
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