Messages in this thread | | | Date | Mon, 21 Apr 2008 11:08:03 -0400 | From | "H. Peter Anvin" <> | Subject | Re: [RFC PATCH] x86 NMI-safe INT3 and Page Fault (v5) |
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Mathieu Desnoyers wrote: > > Just to be clear : the added cost on normal interrupt return is to add a > supplementary test of the thread flags already loaded in registers and > a conditional branch. This is used to detect if we are nested over an > NMI handler. I doubt anyone ever notice an impact caused by this added > test/branch. >
Why the **** would you do this except in the handful of places where you actually *could* be nested over an NMI handler (basically #MC, #DB and INT3)?
-hpa
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