Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set ifavailable

[Peter Zijlstra]

On Thu, 2010-02-18 at 13:29 +0100, Luca Barbieri wrote:
> >> If we use the stack instead of per-CPU variables, all IRQs and NMIs
> >> preserve CR0 and the SSE registers, so this would be safe, right?
> >
> > You'd have to take special care to deal with nested IRQs I think.
> 
> Could you elaborate on that?
> Which issue could there be with nested IRQs?

Depends on where on the stack you're going to save things, I through
you'd take space in the thread_info struct, but I guess if you're simply
going to push the reg onto the stack it should be fine.

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