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SubjectRe: [PATCH 0/24] make atomic_read() behave consistently across all architectures
On Wed, Aug 15, 2007 at 02:49:03PM +0800, Herbert Xu wrote:
> Chris Snook <csnook@redhat.com> wrote:
> >
> > Because atomic operations are generally used for synchronization, which requires
> > volatile behavior. Most such codepaths currently use an inefficient barrier().
> > Some forget to and we get bugs, because people assume that atomic_read()
> > actually reads something, and atomic_write() actually writes something. Worse,
> > these are architecture-specific, even compiler version-specific bugs that are
> > often difficult to track down.
>
> I'm yet to see a single example from the current tree where
> this patch series is the correct solution. So far the only
> example has been a buggy piece of code which has since been
> fixed with a cpu_relax.

Btw.: we still have

include/asm-i386/mach-es7000/mach_wakecpu.h: while (!atomic_read(deassert));
include/asm-i386/mach-default/mach_wakecpu.h: while (!atomic_read(deassert));
Looks like they need to be fixed as well.
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