Re: [PATCH 3/3] tools/power turbostat: allow turbostat to work when aperf is not available

[Len Brown]

Something like this?

diff --git a/tools/power/x86/turbostat/turbostat.c
b/tools/power/x86/turbostat/turbostat.c
index 5bc47ad5da09..4a847e7e9c65 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -8530,7 +8530,7 @@ void rapl_perf_init(void)
 /* Assumes msr_counter_info is populated */
 static int has_amperf_access(void)
 {
-       return msr_counter_arch_infos[MSR_ARCH_INFO_APERF_INDEX].present &&
+       return has_aperf &&
msr_counter_arch_infos[MSR_ARCH_INFO_APERF_INDEX].present &&
            msr_counter_arch_infos[MSR_ARCH_INFO_MPERF_INDEX].present;
 }


On Mon, Dec 1, 2025 at 2:53 PM Len Brown <lenb@xxxxxxxxxx> wrote:
>
> > ...add_msr_perf_counter() returns -1
>
> good.  and then add_msr_counter() succeeds because...
>
> > rdmsr returns zero for MSR_IA32_APERF and MSR_IA32_MPERF.
>
> Your patch is a good suggestion -- though it checks for APERF only and
> not for MPERF.
>
> We already ran CPUID and cleared has_aperf, so I'm thinking we should
> be heading this off earlier.  Let me send you a test patch later today.
>
> thanks,
> Len Brown, Intel Open Source Technology Center



-- 
Len Brown, Intel Open Source Technology Center