Re: [PATCH 6/24] make atomic_read() behave consistently on frv

Chris Snook
2007-08-10T19:55:22Z

David Howells wrote:
> Chris Snook <csnook@redhat.com> wrote:
>
>> To head off the criticism, I admit this is an oversimplification, and true
>> busy-waiters should be using cpu_relax(), which contains a barrier.
>
> Why would you want to use cpu_relax()? That's there to waste time efficiently,
> isn't it? Shouldn't you be using smp_rmb() or something like that?
>
> David

cpu_relax() contains a barrier, so it should do the right thing. For
non-smp architectures, I'm concerned about interacting with interrupt
handlers. Some drivers do use atomic_* operations.

-- Chris