Setting the polling interval

6.10 LPAR mode z/VM guest KVM guest

Request polling is supported at nanosecond intervals.

Before you begin

You cannot use the poll thread in environments that support AP adapter interrupts, see AP adapter interrupts.

Procedure

Use the lszcrypt and chzcrypt commands to read and set the polling time.
Examples:
- To find out the current polling time, issue:
```
# lszcrypt -b
...
poll_timeout=250000 (nanoseconds)
```
- To set the polling time to 1 microsecond, issue:
```
# chzcrypt -t 1000
```
Alternatively, you can set the polling time through the poll_timeout sysfs attribute. This read-write attribute can be found at the AP bus level.
Examples:
- To read the poll_timeout attribute for the ap bus issue:
```
# cat  /sys/bus/ap/poll_timeout
```
- To set the poll_timeout attribute for the ap bus to poll, for example, every microsecond, issue:
```
# echo 1000 > /sys/bus/ap/poll_timeout
```