Re: [all better] Re: regression: massive trouble with fpu rework

From: Mike Galbraith
Date: Mon Jun 29 2015 - 08:27:37 EST


On Mon, 2015-06-29 at 10:33 +0200, Borislav Petkov wrote:

> I bet it is that
>
> /* Unmask CPUID levels if masked: */
> if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) {
> if (msr_clear_bit(MSR_IA32_MISC_ENABLE,
> MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) {
> c->cpuid_level = cpuid_eax(0);
> get_cpu_cap(c);
> }
> }
>
> in early_init_intel(). If you feel like playing, you might comment it
> out to see what happens.

With it commented out, and fpu__init_system() either back at previously
booting position [5] or at original [0], doesn't matter, box is dead,
but differently. It stalls after setting clocksource to tsc, and just
sits there.

-Mike


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