[openib-general] Re: [PATCH][16/26] IB/mthca: mem-free doorbell record writing

[Roland Dreier]

    Jeff> Are you concerned about ordering, or write-combining?

ordering... write combining would be fine.

    Jeff> I am unaware of a situation where writes are re-ordered into
    Jeff> a reversed, descending order for no apparent reason.

Hmm... I've seen ppc64 do some pretty freaky reordering but on the
other hand that's a 64-bit arch so we don't care in this case.  I
guess I'd rather keep the barrier there so we don't have the
possibility of a rare hardware crash when the HCA just happens to read
the doorbell record in a corrupt state.

 - R.