Re: [PATCH 3/3] kref: Remove the memory barriers

[Peter Zijlstra]

On Mon, 2011-12-12 at 23:56 +0100, Oliver Neukum wrote:
> I guess I worried not about the increment, but the decrement.
> Which makes me wonder what happens if you don't intend
> to get the kref again, but need to make sure it is usually freed,
> like:
> 
> CPU A                                                           CPU B
> 
> kref_get(p)
> start_io(p)
>                                                                         [interrupt from IO]
>                                                                         kref_put(p)

I would expect that if something was needed here, the io stack would
provide the barriers since the io completion will probably want to
change state set by the start_io thing.

Anyway, I would put this squarely outside the responsibility of kref.
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