Messages in this thread | | | Date | Wed, 15 Dec 2004 19:10:17 -0700 (MST) | From | Zwane Mwaikambo <> | Subject | Re: [patch, 2.6.10-rc3] safe_hlt() & NMIs |
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On Thu, 16 Dec 2004, Alan Cox wrote:
> On Maw, 2004-12-14 at 23:09, Linus Torvalds wrote: > > On Tue, 14 Dec 2004, Ingo Molnar wrote: > > Now that you mention it, I have this dim memory of the one-instruction > > "sti-shadow" actually disabling NMI's (and debug traps) too. The CPU > > literally doesn't test for async events following "sti". > > > > Or maybe that was "mov->ss". That one also has that strange "black hole" > > for one instruction. > > The mov to ss one is a bit more magic than that however. If you write > 3Gb of mov->ss into memory (ie about 64 pages to thrash the cache and > slow it plus mmap repeatedly) and run it you don't get a vastly long irq > delay at least on intel, not tried the others.
Might this be because you can't rely on interrupt suppression for back to back suppressing instructions?
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