Tunable Kernel Parameters
NAME [Toc] [Back]
NSTREVENT - maximum number of outstanding STREAMS bufcalls
VALUES [Toc] [Back]
Default [Toc] [Back]
Allowed values [Toc] [Back]
0 - 2147483647
Recommended values [Toc] [Back]
DESCRIPTION [Toc] [Back]
This tunable limits the maximum number of outstanding bufcalls that
are allowed to exist in the system at any given time.
This tunable is intended to protect the system against resource
overload caused by the combination of modules running in all streams
issuing an excessive number of bufcalls. The value selected should be
equal to or greater than the combined maximum number of bufcalls that
can be reasonably expected during normal operation from all streams on
the system. bufcalls are used by STREAMS modules in low memory
Who Is Expected to Change This Tunable?
Restrictions on Changing [Toc] [Back]
Changes to this tunable take effect at next reboot.
When Should the Value of This Tunable Be Raised?
When the system has a lot of low memory situations.
What Are the Side Effects of Raising the Value of This Tunable?
If too big a number is chosen, the STREAMS subsystem preallocates more
memory for internal data structures than may be needed. This reduces
the amount of memory available to applications and the system.
When Should the Value of This Tunable Be Lowered?
If the tunable is increased for a particular STREAMS module/driver,
this tunable can be lowered when that STREAMS module/driver is
removed. It should be returned to its previous value. However, HP
does not recommend a value lower than the default value.
What Are the Side Effects of Lowering the Value of This Tunable?
During low memory situations, it will bring down system performance.
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: Sep 2004
Tunable Kernel Parameters
What Other Tunable Should Be Changed at the Same Time as This One?
WARNINGS [Toc] [Back]
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 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
AUTHOR [Toc] [Back]
NSTREVENT was developed by HP.
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: Sep 2004 [ Back ]