pfdat_hash_locks(5)						     OBSOLETE						       pfdat_hash_locks(5)

NAME

       pfdat_hash_locks - OBSOLETE kernel tunable parameter

DESCRIPTION

       The tunable is obsolete and has been removed.  HP-UX will automatically calculate the 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 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 pfdat 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					       pfdat_hash_locks(5)