Hi, Ingo, thanks for your review, On Mon, 2015-08-17 at 12:11 +0200, Ingo Molnar wrote: > So what your changelog fails to mention: > > - You only add this code to the 64-bit kernel. Are 32-bit kernels not > affected? Yes, 32-bit kernel should also do the save/restore operation. I'll adjust them to 64/32-bit common path. > > - the MSR read is done unconditionally. Is MSR_IA32_THERM_CONTROL available > architecturally and readable (and has sensible values) on all 64-bit > capable > x86 CPUs that run this code path? MSR_IA32_THERM_CONTROL is available on Intel Pentium 4, Xeon, Pentium M and later processors, so I think not all the 64/32-bit capable x86 CPUs have this register. Maybe codes like the following would be more reasonable?
save: ctxt->clock_modulation_saved = !rdmsrl_safe(MSR_IA32_THERM_CONTROL, &ctxt->clock_modulation); restore: if (ctxt->clock_modulation_saved) wrmsrl(MSR_IA32_THERM_CONTROL, ctxt->clock_modulation); Thanks a lot. Best Regards, Yu N�����r��y����b�X��ǧv�^�){.n�+����{����zX����ܨ}���Ơz�&j:+v�������zZ+��+zf���h���~����i���z��w���?�����&�)ߢf��^jǫy�m��@A�a��� 0��h���i