CVS commit: syssrc/sys/dev/pci

[Jason R Thorpe <thorpej%netbsd.org@localhost>]

Module Name:    syssrc
Committed By:   thorpej
Date:           Tue Jul  9 14:52:38 UTC 2002

Modified Files:
        syssrc/sys/dev/pci: if_wm.c

Log Message:
Make a few performance tweaks:
* Bump the number of Rx descriptors from 128 to 256.
* Don't use a sliding Tx interrupt window.  Instead, just do reap-behind
  when we have <= 1/8 of our available descriptors in wm_start().
* Don't use Tx Queue Empty interrupts, and always set the Tx Interrupt
  Delay bit in the Tx descriptor.
* In wm_intr(), always call wm_rxintr() and wm_txintr(), regardless of
  their respective ISR bits being set.  We're here, might as well do some
  work.
* Adjust the Tx and Rx interrupt delay timer values.  New values from
  Intel's driver for FreeBSD via Allen Briggs.

With these changes, NetBSD can sustain > 900Mb/s userland to userland
*without* using TCP checksum offload using Intel PRO/1000 XT cards.


To generate a diff of this commit:
cvs rdiff -r1.9 -r1.10 syssrc/sys/dev/pci/if_wm.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.