36 Brocade Adapters Administrator’s Guide
53-1001583-01
Advanced port configuration
3
Interrupt Control Coalesce
Interrupt control coalescing allows the system to optimize CPU utilization by varying the number of
interrupts generated. Increasing the latency monitor timeout value should result in a lower
interrupt count and less CPU utilization, which may result in higher throughput.
You can configure the following interrupt control coalescing parameters per port:
•Interrupt delay time - The host interrupt generation is delayed by the specified duration to
coalesce multiple I/O interrupt events into one. Increasing this value results in fewer interrupts
per multiple interrupt events.
•Interrupt latenc y timer - This va lue helps to minimize I/O latency by avoiding host interrupt
generation to have to wait until the interrupt delay has expired for an I/O throughput.

Configuring the Interrupt Control Coalesce using HCM

1. Select a port from the device tree.
•From the Host Connectivity Manager, select Configure > Advanced Port Configuration.
The Advanced Port Configuration dialog box displays.
OR
•Right-click a port and select Port Configuration > Advanced.
2. Set the latency and delay values:
•Select On from the Interrupt Control Coalesce list.
NOTE
Interrupt Control Coalesce is On by default.
•Specify the latency monitor timeout value in microseconds, if coalesce is set to on. Latency
timeout values supported are 0-225 microseconds for all HBAs, including the Brocade
804 mezzanine card. Setting the latency timeout value to 0 disables the latency monitor
time out interrupt.
•Specify the delay timeout value in microseconds, if coalesce is set to on. Delay timeout
values supported are 0-1125 microseconds for all HBAs, including the Brocade 804
mezzanine card. Setting the delay timeout value to 0 disables the latency monitor time out
interrupt.
3. Click OK.