Such code generally doesn't care precisely when it gets the update, 
just that the update is atomic, and it doesn't loop forever.

Yes, it _does_ care that it gets the update _at all_, and preferably
as early as possible.

Regardless, I'm convinced we just need to do it all in assembly.

So do you want "volatile asm" or "plain asm", for atomic_read()?
The asm version has two ways to go about it too...


Segher