NAME
NSTREVENT — maximum number of outstanding STREAMS bufcalls
VALUES
Allowed values
0 - 2147483647
DESCRIPTION
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 situations.
Who Is Expected to Change This Tunable?
Any customer.
Restrictions on Changing
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.
What Other Tunable Should Be Changed at the Same Time as This One?
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 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
http://docs.hp.com.
AUTHOR
NSTREVENT
was developed by HP.
Printable version
