Bad routing performance on 500Mhz Geode LX with CURRENT, ipfw and mpd5 (was: ipfw, "ip|all" proto and PPPoE -- does PPPoE packets passed to ipfw?)

[Lev Serebryakov]

Hello, Adam.
You wrote 31 августа 2012 г., 0:32:25:

AVM> BUGS
AVM>      The vr driver always copies transmit mbuf chains into longword-aligned
AVM>      buffers prior to transmission in order to pacify the Rhine chips.  If
AVM>      buffers are not aligned correctly, the chip will round the supplied
AVM>      buffer address and begin DMAing from the wrong location.  This buffer
AVM>      copying impairs transmit performance on slower systems but cannot be
AVM>      avoided.  On faster machines (e.g. a Pentium II), the performance
AVM> impact
AVM>      is much less noticeable.
 Really, this is not truth. Or, to be more specific, it is not
 complete truth. Now if_vr copies data only for some chips (quirk
 VR_Q_NEEDALIGN in sources). My chips (VT6105M) don't need it, and
 driver doesn't copy data for them.

-- 
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>