Re: [BUG] x86 kenel won't boot under Virtual PC

From: H. Peter Anvin
Date: Fri Sep 05 2008 - 16:16:00 EST


Jan Beulich wrote:

I disagree here: If I configure a 686+ kernel, I expect these NOPs to be
that way (and to work). If you want to run on something that's not
compliant, you just shouldn't configure your kernel that way.


Okay, we do not generate P6 NOPs statically if CONFIG_X86_GENERIC_CPU is enabled -- unless, of course gcc/binutils generates them, which they now do for certain CPU types. If you are selecting a specific CPU *and* you don't select GENERIC, you should get valid code for the selected CPU only.

As far as using them dynamically, there is code in -tip that determines dynamically and explicitly if the long NOPs are available, and only uses them if they are.

-hpa
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