HP-UX Reference (11i v3 07/02) - 5 Miscellaneous Topics (vol 9)

c
chanq_hash_locks(5) chanq_hash_locks(5)
(Tunable Kernel Parameters)
NAME
chanq_hash_locks - size of hashed pool of spinlocks protecting the channel queue hash tables
VALUES
Failsafe
256
Default
256
Allowed values
Any value between 16 and 16777216 that is a power of two.
Recommended values
Default value only.
HP does NOT recommend changing this tunable from the default value. Consult your HP Field Service
engineer before changing this tunable.
DESCRIPTION
This tunable should NOT be changed. The default value is the best choice for optimal system performance.
This tunable controls the size of a pool of spinlocks (kernel data structures used for synchronization) that
also protect channel queues. A very small value increases the probability of collisions in the channel queue
hash tables and degrading performance. Very large values are unnecessary.
Who Is Expected to Change This Tunable?
HP does NOT recommend changing this tunable from the default value. Consult your HP Field Service
engineer before changing this tunable.
Restrictions on Changing
This tunable should be a power of two. If another value is specified, the largest value (lower than the given
value) that is a power of two is used.
What Are the Side Effects of Raising or Lowering the Value?
The performance of the system could deteriorate.
What Other Tunables Should Be Changed at the Same Time?
None.
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 parame-
ter values. After installation, some tunable parameters may no longer be at the default or recommended
values. For information about the effects of installation on tunable values, consult the documentation for
the kernel software being installed. For information about optional kernel software that was factory
installed on your system, see HP-UX Release Notes at http://docs.hp.com.
AUTHOR
chanq_hash_locks was developed by HP.
86 Hewlett-Packard Company − 1 − HP-UX 11i Version 3: February 2007