Messages in this thread | | | Date | Mon, 11 May 2009 14:05:14 +0200 | From | Ingo Molnar <> | Subject | Re: [tip:perfcounters/core] perf_counter, x86: remove X86_FEATURE_ARCH_PERFMON flag for AMD cpus |
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* Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> On Mon, 2009-05-11 at 12:02 +0200, Ingo Molnar wrote: > > * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote: > > > > > There is one more way to check performance monitor support for > > > Intel by using IA32_MISC_ENABLE MSR (0x1A0) bit 7 tells whether > > > performance monitoring is available or not. > > > > > > But IA32_MISC_ENABLE MSR (0x1A0) is not available for Pentium and > > > P6. > > > > > > So better I will add new cpufeature for performance monitoring for > > > x86: > > > > > > X86_FEATURE_PERFMON : Performance monitor support > > > > What is the exact wording of IA32_MISC_ENABLE bit 7 in the Intel > > documents? > > > > Bit 7: Performance Monitoring Available. (R) > 1 = Performance monitoring enabled > 0 = Performance monitoring disabled
i guess, if 'perfmon' is not used yet ('arch_perfmon' is), we could add this as a separate, new cpu features flag.
Although the confusion factor is high ...
Ingo
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