Subject: Re: e1000 performance hack for ppc64 (Power4)

From: "David S. Miller" <[email-masked]>
Date: Fri, 13 Jun 2003 16:52:50 -0700 (PDT)

From: "Feldman, Scott" <[email-masked]>
   Date: Fri, 13 Jun 2003 16:52:18 -0700

   > > Why not instead find out if it's possible to have the e1000 
   > > fetch the entire cache line where the first byte of the
   > > packet resides?  Even ancient designes like SunHME do that.
   > 
   > Rusty and I were wondering why the e1000 didnt do that exact thing.
   > 
   > Scott: is it possible to enable such a thing?
   
   I thought the answer was no, so I double checked with a couple of
   hardware guys, and the answer is still no.

Sigh...

So Anton, when the PCI controller gets a set of sub-cacheline word
reads from the device, it reads the value from memory once for every
one of those words?  ROFL, if so...  I can't believe they wouldn't
put caches on the PCI controller for this, at least a one-behind that
snoops the bus :(