Re: [patch, 2.6.10-rc3] safe_hlt() & NMIs

From: Maciej W. Rozycki
Date: Thu Dec 16 2004 - 10:44:02 EST

On Thu, 16 Dec 2004, Ingo Molnar wrote:

> The 'sti' "shadows" the cli, i.e. we'll never get an interrupt that gets
> inbetween 'sti;cli'. I.e. sti is the black-hole generator, and 'cli' is
> in the black hole. In that sense the 'cli' is in a black hole to the
> NMI: the NMI will never see cli as the 'next to be executed'
> instruction.

That's what I meant indeed, but I'd like to emphasise, for readers to be
aware, the black hole is not tied to the 'cli' instruction itself in any
way. The black-holed instruction needs not be a 'cli' -- it can be an
arbitrary one except from ones creating black holes as you've observed
with your test.

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