On Wed, 29 Oct 2014, Manuel Selva wrote:
> I am trying to setup load latency sampling on a Sandy Bridge processor (Cpu
> familly 6, model 42, model name Intel(R) Core(TM) i5-2520M CPU @ 2.50GHz)
> running a 3.13 linux kernel.
>
> After deep investigations made of reading of the Intel SDM, examples provided
> by the pfm library and the source code of perf, I am still not able to get
> sample. I think for now that my problem is related to the precise_ip parameter
> of the perf_event_attr structure.
>
> Any time I change this value from 0 to 1 or from 0 to 2 (2 is the value to
> enable PEBS isn't it ?) the perf_event_open system call failed with a "Not
> supported operation" error. Running perf mem record on this Sandy Bridge
> platform also result in the same error.
Which event are you trying to use?
On my Ivybrige machine using 3.14 I am able to get latency values with
pe.config=0x1cd;
pe.config1=3;
pe.precise_ip=2;
Vince
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