No, "lock held forever" merely makes the example trivial.
"Lock held for a while" is the real problem.
> > You really do need that cmpxchg loop.
>
> Well, not decrementing if count < 0 already also works
How, exactly, are you planning on doing that atomically?
Clue: 386 SMP requires an extra spinlock.
> PS. Will Alpha have to do any special magic with the mmap PROT_SEM flag?
No.
r~
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