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Re: enhanced speed step on AMD64

On Sun, May 23, 2010 at 05:48:07PM +0100, Iain Hibbert wrote:
> On Sun, 23 May 2010, wrote:
> > Yup, and none of that works -- I've got a Pentium M with speedstep
> > successfully running, so I'm aware of the interface, etc. Was wondering
> > if something changed in the meantime that I missed... I'll leave this
> > thread out there in the hope that someone can shed some light, or set
> > me on the right path...
> reading the code (at arch/x86/x86/est.c) seems to indicate that "boot -x"
> should cause _some_ kind of message to be emitted if the est_init()
> function is called. You could also build a kernel with "options EST_DEBUG"
> which will print more..
> Then, the code that calls est_init() (in arch/x86/x86/identcpu.c) shows
>       if (cpu_feature[1] & CPUID2_EST) {
>               if (rdmsr(MSR_MISC_ENABLE) & (1 << 16))
>                       est_init(cpu_vendor);
>       }
> and on my machine, "cpuctl identify 0" shows
>   cpu0: features2 0xc1a9<SSE3,MONITOR,VMX,EST,TM2,xTPR,PDCM>
> I don't know what MSR_MISC_ENABLE means, perhaps just that the CPU is
> enabled..?

Thanks Iain -- rebuilding a kernel w/ EST_DEBUG right now... my cpuctl
is as follows (I'm pasting whole thing, since this appears to be a
"problem" CPU:

kamloops# cpuctl identify 0
cpu0: Intel Mobile Pentium II (Dixon) (686-class), 2660.22 MHz, id 0x20652
cpu0: features  0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR>
cpu0: features  0xbfebfbff<PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR>
cpu0: features  0xbfebfbff<SSE,SSE2,SS,HTT,TM,SBF>
cpu0: features2 0x298e3ff<SSE3,B01,DTES64,MONITOR,DS-CPL,VMX,SMX,EST,TM2>
cpu0: features2 0x298e3ff<SSSE3,CX16,xTPR,PDCM,SSE41,SSE42,POPCNT,B25>
cpu0: features3 0x28100800<SYSCALL/SYSRET,XD,EM64T>
cpu0: features4 0x1<LAHF>
cpu0: "Intel(R) Core(TM) i7 CPU       M 620  @ 2.67GHz"
cpu0: I-cache 32KB 64B/line 4-way, D-cache 32KB 64B/line 8-way
cpu0: L2 cache 256KB 64B/line 8-way
cpu0: ITLB 128 4KB entries 4-way
cpu0: DTLB 64 4KB entries 4-way
cpu0: L3 cache 4MB 64B/line 16-way
cpu0: Initial APIC ID 0
cpu0: Cluster/Package ID 0
cpu0: Core ID 0
cpu0: SMT ID 0
cpu0: family 06 model 05 extfamily 00 extmodel 02

> iain

Brad Harder
Method Logic Digital Consulting

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