Messages in this thread | | | Date | Fri, 01 Apr 2011 13:21:59 -0700 | From | "H. Peter Anvin" <> | Subject | Re: 2.6.38.2 breaks suspend to disk |
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On 04/01/2011 12:54 PM, Yinghai Lu wrote: > > ok, please check if you are happy with this one. >
The best would simply be:
mmu_cr4_features = read_cr4_safe();
If this has to run before we can handle exceptions, one can verify the existence by testing for the CPUID instruction (a CPU has CR4 if and only if it has CPUID):
if (boot_cpu_data.cpuid_level >= 0) mmu_cr4_features = read_cr4_safe();
... since we set cpuid_level to -1 if there is no CPUID instruction.
-hpa
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