Re: [PATCH] Document Linux's memory barriers

[Nick Piggin <nickpiggin@yahoo.com.au>]

Paul Mackerras wrote:
> David Howells writes:

> > +     The way to deal with this is to insert an I/O memory barrier between the
> > +     two accesses:
> > +
> > +	*ADR = ctl_reg_3;
> > +	mb();
> > +	reg = *DATA;
>
>
> Ummm, this implies mb() is "an I/O memory barrier".  I can see people
> getting confused if they read this and then see mb() being used when
> no I/O is being done.

Isn't it? Why wouldn't you just use smp_mb() if no IO is being done?

--
SUSE Labs, Novell Inc.
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