Re: Linux 2.6.32-rc1

Stefan Richter
2009-09-30T17:41:30Z

Linus Torvalds wrote:
> On Wed, 30 Sep 2009, Stefan Richter wrote:
>> As long as it can't be turned into an atomic access, shouldn't cmpxchg64
>> be hidden from the common kernel coder? Almost everybody will assume
>> that it is an atomic operation and happily use it in unsafe places.
>
> But it _is_ atomic. We don't support SMP on the platforms that we have to
> do it with emulation on.
>
> There's a theoretical problem with NMI, but it's not one we can solve or
> that is really all that interesting, so might as well ignore it.

Ah, right, I could have taken a hint from /* disable interrupts */ in
Arjan's cmpxchg8b_emu.
--
Stefan Richter
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