On 2016-06-10, Jed Clear <[email protected]> wrote: >> The vr driver always copies transmit mbuf chains into longword-aligned >> buffers prior to transmission in order to pacify the Rhine chips. If >> buffers are not aligned correctly, the chip will round the supplied >> buffer address and begin DMAing from the wrong location. This buffer >> copying impairs transmit performance on slower systems but cannot be >> avoided. On faster machines (e.g. a Pentium II), the performance >> impact >> is much less noticeable. > > Interesting. You'd think the drivers would align the packets on Rx and I > vaguely recall that FreeBSD managed to go zero copy a few major versions ago. > Although that could be for straight forwarding. IPFW and NAT might behave > differently. Not sure I'd have any control over it.
The manpage is outdated, this is only done for the old chips. It's not needed and isn't done for VT610x. _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
