Re: [patch] linux 2.4.17: The second mb() rework (final)

[Dominic Sweetman <dom@algor.co.uk>]

Kevin D. Kissell (kevink@mips.com) writes:

> > Note that SYNC on TX39/H and TX39/H2 does not flush a write buffer.
> > Some operation (for example, bc0f loop) are required to flush a write
> > buffer.
> 
> That is, I would say, a bug in the TX39 implementation of SYNC.

That's only a problem if the CPU permitted reads to overtake buffered
writes.  [Early R3000 write buffers did that (with an address check to
avoid the disaster of allowing a read to overtake a write to the same
location).]

But my recollection is that the TX39 does all memory operations in
order: so SYNC has very little to do, but it isn't a bug.

Dominic Sweetman
Algorithmics