NAME
intr_strobe_ics_pct — limit for the percent of time a processor is allowed to spend in interrupt context
VALUES
Allowed values
80 - 100
Setting
intr_strobe_ics_pct
to
100
will switch the feature off.
DESCRIPTION
intr_strobe_ics_pct
specifies the system limit
for the percent of time a processor is allowed to spend in interrupt context.
When the tunable is set to a value less than
100,
the kernel does not allow
I/O interrupts to consume the processor time beyond the set limit and hence
the threads and other low priority interrupts get time to execute.
This is
important when the system is under a heavy I/O interrupt load and some threads
like heartbeat timer in service guard environment need to run within a limited
time delay.
In the normal working of the system, the value of the tunable
intr_strobe_ics_pct
should be
80.
If
intr_strobe_ics_pct
is to less than
100,
a message like the following may be seen in the message buffer.
An interrupt context threshold of #% was exceeded on processor #
within the last # minutes. The current value is #.
The message buffer can be read via
dmesg
or
syslog.
This message indicates that the percent of time spent on the processor
crossed the specified limit and corrective action has been taken.
Who Is Expected to Change This Tunable?
Only HP Field engineers should change the value of this tunable.
Restrictions on Changing
Changes to this tunable take effect immediately.
When Should the Value of This Tunable Be Lowered?
The value should be lowered only when heavy I/O interrupt load is
causing a time critical process to timeout.
What Are the Side Effects of Lowering the Value?
Reducing the value of the tunable would give the thread context
more time to execute.
However, the overall system throughput may decrease.
What Other Tunable Values Should Be Changed at the Same Time?
This tunable is independent of other tunables.
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
intr_strobe_ics_pct
was developed by HP.
Printable version
