Re: [PATCH] perf/x86: fix uncore PCI fixed counter handling

From: Andi Kleen
Date: Tue Sep 10 2013 - 16:23:02 EST


On Mon, Sep 09, 2013 at 12:53:50PM -0700, Stephane Eranian wrote:
>
> There was a bug in the handling of SNB-EP/IVB-EP uncore PCI
> fixed counters, e.g., IMC. It would cause erratic values to
> be returned for the IMC clockticks event. This was due to
> a bogus hwc->config value which was then written to PCI
> config space. The fixed counter has most fields marked as
> reserved with hw reset values of 0. Yet the kernel was
> defaulting to a hwc->config = ~0 and that was causing
> the issues. The patch sets the hwc->config values for fixed
> uncore event to 0. Now, the values of imc clockticks is
> correct.
>
> $ perf stat -a -C 0 -e uncore_imc_0/clockticks/ -I 1000 sleep 10

Looks good to me.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

-Andi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/