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region_hash_locks(5) [hpux man page]

region_hash_locks(5)						     OBSOLETE						      region_hash_locks(5)

NAME
region_hash_locks - OBSOLETE kernel tunable parameter DESCRIPTION
The tunable is obsolete and has been removed. HP-UX will automatically calculate its value based on the system configuration. Global kernel structures containing information on a running process or memory usage are frequently accessed or modified by several threads concurrently. To prevent race conditions, these structures are protected by spinlocks (kernel data structures used for synchronization) which allow only the spinlock "holder" to proceed, while all others attempting to access the structure must wait. Hashed spinlocks are used when each instance of such a data structure is to be protected, and there are several instances. Using a single spinlock for all instances would cause too much contention, but using one spinlock per structure wastes memory while the majority of the locks are unused at any given time. By allocating a pool of hashed locks, a hash function picks one lock per group of structures, reducing contention while conserving memory. The system-calculated value of sets the size of such a pool for the region data structure spinlocks. WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of HP-UX. Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation, some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun- able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was factory installed on your system, see at AUTHOR
was developed by HP. Tunable Kernel Parameters region_hash_locks(5)

Check Out this Related Man Page

scsi_maxphys(5) 						File Formats Manual						   scsi_maxphys(5)

NAME
scsi_maxphys - maximum allowed length of an I/O on all SCSI devices (OBSOLETE) VALUES
Failsafe Default Allowed values Recommended values DESCRIPTION
Note: This tunable is obsolete. It is replaced by the attribute, which can be get and set using the command (see scsimgr(1M)). This tunable sets the maximum data size the SCSI subsystem will accept for an I/O. Depending on the device's characteristics and the device driver configuration, the maximum size allowed by the SCSI subsystem for a particular SCSI device might be lower than or equal to this tunable's value. It will never be greater. Who Is Expected to Change This Tunable? Any customer. Restrictions on Changing Changes to this tunable will take effect when the device is first opened. When Should the Value of This Tunable Be Raised? The value should never be raised. When Should the Value of This Tunable Be Lowered? The value should never be lowered. What Other Tunables Should Be Changed at the Same Time as This One? None. WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter has been obsoleted for HP-UX 11i Version 3. Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation, some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun- able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was factory installed on your system, see at AUTHOR
was developed by HP. OBSOLETE
Tunable Kernel Parameters scsi_maxphys(5)
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