AIX Version 4.3 Differences Guide

thread will have a chance to handle the event. The other threads will simply go
back to sleep.
In AIX Version 4.3.2, only a single thread is awakened, thus reducing CPU
overhead. And the system now is able to handle higher loads of socket
connections. Industry multi-threaded network server application developers will
appreciate that AIX Version 4.3.2 overcomes the thundering herd problem of
wasted CPU cycles resulting from waking up multiple threads of a network server
when new connections arrive.
7.12 IBM 10/100 Mbps PCI Ethernet Adapter Device Driver (4.3.2)
In previous AIX version, the Ethernet device driver copies data from mbufs to its
own buffers. Recent prototypes have shown that transmitting data directly from
mbufs would lead to better performance.
AIX 4.3.2 provides a new device driver for IBM 10/100 Mbps PCI Ethernet
adapter. The new device driver reduces data copy operations from network
buffers to its private buffers. The network performance in AIX 4.3.2 benefits from
enhancements in this new PCI network device drivers. These enhancements
reduce CPU demand, thus increasing overall server capacity.
The device driver supports the PCI 10/100 Ethernet adapter for AIX Versions
4.2.1 and 4.3.0. The new PCI 10/100 Ethernet is modified to support AUI and
BNC ports starting at AIX 4.3.2 and is backwards compatible. The performance
enhancements for reducing the data copies in AIX 4.3.2 is backwards compatible
to AIX 4.2.
The device driver is conform to the Common Data Link Interface (CDLI) interface
specifications.
This adapter now supports the twisted pair, AUI and BNC ports.
The speeds supported are:
• 10 (10 Mbps, half-duplex)
• 20 (10 Mbps, full-duplex)
• 100 (100Mbps, half-duplex)
• 200 (100Mbps, full-duplex)
• Auto-negotiate.
7.12.1 Packaging
The PCI 10/100 Ethernet adapter software package includes:
devices.pci.23100020.rte
devices.pci.23100020.diag
178 AIX Version 4.3 Differences Guide