Technical data

System Management Features
4.10 OpenVMS SMP Performance Improvements (Alpha)
Prior to OpenVMS Version 7.3, the mailbox driver FDT routines called
a routine that locked the MAILBOX spinlock and delivered any required
attention ASTs. In most cases, this routine did not require any attention
ASTs to be delivered. Because the OpenVMS code that makes these calls
already has the MAILBOX spinlock locked, the spinlock acquisition was also
an unneeded second acquire of the spinlock.
As of OpenVMS Version 7.3, OpenVMS now first checks to see if any ASTs
may need to be delivered prior to calling the routine. This avoids both the
call overhead and the overhead of relocking the MAILBOX spinlock that was
already owned.
4.11 New SYSMAN Commands and Qualifiers
The SYSMAN utility has the following new commands:
• CLASS_SCHEDULE commands
The class scheduler provides the ability to limit the amount of CPU time that
a system’s users receive by placing users in scheduling classes.
Command Description
CLASS_SCHEDULE ADD Creates a new scheduling class
CLASS_SCHEDULE DELETE Deletes a scheduling class
CLASS_SCHEDULE MODIFY Modifies the characteristics of a
scheduling class
CLASS_SCHEDULE RESUME Resumes a scheduling class that has
been suspended
CLASS_SCHEDULE SHOW Displays the characteristics of a
scheduling class
CLASS_SCHEDULE SUSPEND Temporarily suspends a scheduling class
• IO FIND_WWID and IO_REPLACE_WWID (Alpha-only)
These commands support Fibre Channel tapes, which are discussed in
Section 4.9.4.1.
Command Description
IO FIND_WWID Detects all previously undiscovered
tapes and medium changers
IO REPLACE_WWID Replaces one worldwide identifier
(WWID) with another
• POWER_OFF qualifier for SYSMAN command SHUTDOWN NODE
The /POWER_OFF qualifier specifies that the system is to power off after
shutdown is complete.
For more information, refer to the SYSMAN section of the OpenVMS System
Management Utilities Reference Manual: M–Z.
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