Re: NS83820 2.6.0-test5 driver seems unstable on IA64

David Mosberger
2003-09-27T04:34:13Z

>>>>> On Sat, 27 Sep 2003 06:26:40 +0200, Andi Kleen <ak@muc.de> said:

Andi> You handle misalignment->misalignment copies with zero or
Andi> small cost - when both source and destination have the same
Andi> misalignment. I guess you do that by just aligning the pointer
Andi> at the beginning of the function. That works as long as both
Andi> source and destination have the same misalignment.

Andi> But that is not what happens here. The copy is a
Andi> misaligned->aligned copy and that cannot be handled at zero
Andi> cost (unless you have zero misalignment penalty in
Andi> load/store). Either the load or the store in the copy loop
Andi> will be always misaligned, no matter what tricks you play. You
Andi> cannot avoid this by aligning the pointers.

Geez, Andi, get a clue. You've been working with x86 for too long.

You really can't imagine that you could combine two source words into
a single destination word? Look ma, no unaligned accesses...

--david