intr_strobe_ics_pct(5)intr_strobe_ics_pct(5)NAMEintr_strobe_ics_pct - limit for the percent of time a processor is
allowed to spend in interrupt context
Setting to will switch the feature off.
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 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 heart‐
beat timer in service guard environment need to run within a limited
In the normal working of the system, the value of the tunable should be
If is to less than a message like the following may be seen in the mes‐
The message buffer can be read via or 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 caus‐
ing 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.
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
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 val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
was developed by HP.
SEE ALSOkctune(1M), kcweb(1M).
Tunable Kernel Parameters intr_strobe_ics_pct(5)