clshmctl(1M)
clshmctl - Administration tool for CrayLink Shared Memory
As shipped in IRIX 6.5.5. Last changed in IRIX 6.5.5.
NAME clshmctl - Administration tool for CrayLink Shared Memory SYNOPSIS clshmctl startup clshmctl shutdown clshmctl getcfg clshmctl maxpgs <num of pages> clshmctl maxdpgs <num daem pages> clshmctl timeout <daemon timeout> 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 has a system V shared memory interface in the form of a user library (xp_func(3p) and part_func(3p)) that can be used 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 clshmd(1m) daemon 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/sn0start and is required before any inter-partition communication can be effected over CrayLink Shared Memory. This startup at bootup time must be enabled using the chkconfig(1m) command for clshmd(1m). 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 clshmd(1m) daemon is made to exit and the resources associated with the clshm software devices are released. clshmctl shutdown should be used carefully since any user- program using the clshm devices will be killed when this function is called. getcfg Returns the configuration of clshm on the local partition. The parameters configurable through clshmctl are the maximum number of 16K pages of shared-memory that are supported, the number of 16K pages shared between the daemon and the kernel driver, and the timeout time before the clshmd(1m) daemon wakes up from sleeping and checks for a message from the driver when there is no user activity going on. 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 clshmctl startup has been called (without another clshmctl shutdown). In order to set this parameter, the clshmd(1m) daemon must be in the shutdown state. clshmctl maxdpgs <num daem pages> Sets the maximum number of shared memory pages that the clshm driver can use to communicate with the clshmd(1m) daemon. Like maxpgs, this call will fail if made after a clshmctl startup call has been made. clshmctl timeout <daemon timeout> Sets the timeout value in milliseconds that the clshmd(1m) daemon will sleep before checking for messages in the shared memory segment from the driver. If there are messages coming in on either other daemon or user sockets, then the driver will not sleep the full amount of the timeout, but will process all messages if fines on all sockets and in the shared memory segment. WARNINGS If the clshmd(1m) daemon aborts abnormally a clshmctl shutdown must be called before a clshmctl startup can be called again to restart the shared-memory mechanism. FILES /etc/init.d/sn0start SEE ALSO clshmd(1m), chkconfig(1m), xp_func(3p), part_func(3p), clshm_diag(1m), mkpart(1m)