Re: [PATCH] perf,x86: add constraint for IVBCYCLE_ACTIVITY:CYCLES_LDM_PENDING

[Andi Kleen]

On Wed, Sep 11, 2013 at 08:22:22AM -0700, Stephane Eranian wrote:
> 
> The IvyBridge event CYCLE_ACTIVITY:CYCLES_LDM_PENDING can only
> be measured on counters 0-3 when HT is off. When HT is on, you
> only have counters 0-3.
> 
> If you program it on the eight counters for 1s on a 3GHz
> IVB laptop running a noploop, you see:
> 
>            2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>            2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>            2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>            2 747 527 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>        3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>        3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>        3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
>        3 280 563 608 CYCLE_ACTIVITY:CYCLES_LDM_PENDING
> 
> Clearly the last 4 values are bogus.

Thanks looks good.

Likely need it on Haswell too?

-Andi
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