Avago Technologies LSI20320 - Manual (Page 14)

8 Fusion-MPT FCode User’s Guide
Copyright © 2000-2004 by LSI Logic Corporation. All rights reserved.
3.3.3 show-children
Use the show-children command while the adapter or port is selected
to display the devices currently connected to this adapter. Select the port
or adapter shown (use the port name your system assigns):
ok select /pci@1f,0/pci@1/pci@1/LSILogic,scsi@c
ok show-children
MPT Version 1.02, Firmware Version 1.00.00
Target 0
Unit 0 Disk QUANTUM ATLAS IV 9 WLS 0B0B 17942584 Blocks, 8971 MB
Target 1
Unit 0 Disk QUANTUM ATLAS IV 9 WLS 0B0B 17942584 Blocks, 8971 MB
Target 2
Unit 0 Disk QUANTUM ATLAS IV 9 WLS 0B0B 17942584 Blocks, 8971 MB
Target 3
Unit 0 Disk QUANTUM ATLAS IV 9 WLS 0B0B 17942584 Blocks, 8971 MB
3.4 Interrupt Coalescing
Interrupt coalescing allows the firmware on the Fusion-MPT device to
group I/Os together in order to minimize the overhead to the host system.
This feature can result in significant performance benefits when I/Os are
coming into the adapter rapidly—for example, when performing small
sequential reads from a disk.
LSI Logic has tested interrupt coalescing under multiple I/O conditions
and has determined that the following interrupt coalescing values are
beneficial over a wide range of I/O conditions:
•
timeout = 160 microseconds
•
depth = 4
With these settings the host is interrupted only once for four I/Os
processed by the chip, unless a time of 160 microseconds has passed
since the host was last interrupted.
Although LSI Logic has determined that these settings are optimal for a
wide variety of situations, your system’s I/O load may benefit from a
deeper queue or a longer timeout. LSI Logic provides a mechanism to