Messages in this thread | | | Date | Thu, 14 Jul 2005 11:04:13 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt |
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On Wed, 13 Jul 2005, Benjamin LaHaise wrote:
> That's one thing I truely dislike about the current timer code. If we > could program the RTC interrupt to come into the system as an NMI (iirc > oprofile already has code to do this), we could get much better TSC > interpolation since we would be sampling the TSC at a much smaller, less > variable offset, which can only be a good thing.
And we'd get a lot more crashes on broken systems that do not handle NMIs in the SMM -- this is the very reason the NMI watchdog is disabled these days by default. A whole lot of systems simply cannot handle NMIs happening randomly.
Programming an I/O APIC to deliver the RTC interrupt (or any other that's edge-triggered) as an NMI is itself trivial (we can do this for the PIT for the NMI watchdog already).
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