[openib-general] [RFC/BUG] DMA vs. CQ race

[akepner at sgi.com]

In:

http://openib.org/pipermail/openib-general/2006-December/030251.html

I described a potential race between DMA and CQ updates on
Altix systems. At that time the bug hadn't been observed,
but was expected to be possible on "large" NUMA systems.

A first-cut at a patch was sent out, some very reasonable
objections were raised, and the thread fizzled out.

Since that time we've been able to produce the bug, and show
that the patch I sent fixes the problem. (OK, the patch I sent
with the addition of a small but important patchlet.)

The biggest concern with the earlier patch seemed to be
backward compatibility. There was a stab at addressing
that in http://tinyurl.com/2x3s52, but no commentary.
(Too ugly for words?)

Any suggestions as to how to proceed? Should I just code
something up in order to have a concrete target to discuss?
Or are there any new thoughts based on the previous emails?

-- 
Arthur