On Wed, Sep 28, 2011 at 9:47 AM, Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
>
> Could do something like:
>
> if (ticket->head >= 254)
> prev = xadd(&ticket->head_tail, 0xff02);
> else
> prev = xadd(&ticket->head_tail, 0x0002);
>
> to compensate for the overflow.
Oh wow. You havge an even more twisted mind than I do.
I guess that will work, exactly because we control "head" and thus can
know about the overflow in the low byte. But boy is that ugly ;)
But at least you wouldn't need to do the loop with cmpxchg. So it's
twisted and ugly, but migth be practical.
Linus
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