Re: [linux-pm] [RFC][PATCH -mm 1/5] PM: Make freeze_processes SMP-safe

Alan Stern
2006-11-27T02:41:35Z

On Mon, 27 Nov 2006, Pavel Machek wrote:

> Hi!
>
> > > If frozen is atomic_t, do we need memory barrier?
> >
> > I think so. For example on x86-64 atomic_read() is just a read.
>
> I'm not sure, but for x86-64 barriers are nops, anyway, IIRC.

atomic_read() does not include its own memory barrier. If you want one,
you have to write it yourself. At least, that's how I interpret
Documentation/atomic_ops.txt.

Alan Stern