Messages in this thread | | | Date | Thu, 7 Mar 2002 00:48:21 -0800 | From | Richard Henderson <> | Subject | Re: [PATCH] Fast Userspace Mutexes III. |
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On Thu, Mar 07, 2002 at 02:39:47PM +1100, Rusty Russell wrote: > But since the real problem here is "lock held forever", so I don't care.
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.
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