Messages in this thread | | | From | "Andrejczuk, Grzegorz" <> | Subject | RE: [PATCH v6: 2/4] x86: Add enabling of the R3MWAIT during boot | Date | Thu, 27 Oct 2016 16:53:45 +0000 |
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> > init_intel_energy_perf(c); > > + > > + /* > > + * Setting ring 3 MONITOR/MWAIT for thread > > + * when CPU is Xeon Phi Family x200 (KnightsLanding). > > + */ > > + if (c->x86 == 6 && c->x86_model == INTEL_FAM6_XEON_PHI_KNL) > > Please move this conditional into the probe function. > > > + probe_xeon_phi_r3mwait(c); > > Can you please check with your hardware people, whether this function is somewhere detectable. bit 0 of the MISC_*FEATURE* MSR (Ring 3 CPUID fault > enable) is detectable via the PLATFORM_INFO MSR. I would be surprised if this thing is not detectable in some way. > > I really prefer detectable things over hardcoded crap which depends on model information.
I asked hardware people and MSR 0x140 should be called MSR_MISC_FEATURE_ENABLES and there is no other feature MSR indicating that this bit can be set. Unfortunately hardcoded crap has to be used.
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