barnett@im4u.UUCP (Lewis Barnett @ home on the range) (11/13/86)
About a week ago, I posted the following article. It was during the crossover period from net.unix-wizards to comp.unix.wizards, so it might not have made it here. So far, I have received only inquiries from people who are interested in what I learn. ___________________________ I recently noticed that although the Interlan NI1010 Ethernet controller has a large onboard receive buffer and a queue for sixteen pointers to Unibus buffers for DMA ... the 4.3BSD driver (if_il.c) uses only one Unibus buffer for packet reception. I'm interested in increasing the reception performance of the driver, and I wondered if anyone had considered extending the code to use more than one Unibus buffer. I'd be interested in any information, from actual implementation to mere musings. If I receive sufficient response, I'll summarize. ____________________________ To add some context, I've written some network monitoring software that uses the NI1010. It keeps up pretty well up to around 12% utilization, but starts losing a significant percentage of packets at higher utilization. Providing more buffers for DMA *should* improve this performance, but I haven't completely succeeded in my attempts to take advantage of this feature of the board. Any insights greatly appreciated. Lewis Barnett,CS Dept, Painter Hall 3.28, Univ. of Texas, Austin, TX 78712 -- barnett@im4u.UTEXAS.EDU, barnett@im4u.UUCP, {ihnp4,harvard,seismo,gatech,ctvax}!im4u!barnett