Re: [PATCH v9 0/8] perf/amd/iommu: Enable multi-IOMMU support

From: Borislav Petkov
Date: Wed Feb 15 2017 - 05:13:51 EST


On Tue, Feb 07, 2017 at 02:40:28AM -0600, Suravee Suthikulpanit wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
>
> This patch series modifies the existing IOMMU and Perf drivers to support
> systems with multiple IOMMUs by allocating an amd_iommu PMU per IOMMU instance.
> This allows users to specify performance events and filters separately for each
> IOMMU.
>
> This has been tested on the new family17h-based server w/ multiple IOMMUs.

Ok, so far so good.

There's just one thing:

$ perf stat -e amd_iommu_X/Y

says <not supported> and only doing the system wide tracing with -a does
it count events.

So, lemme ask perf tool people, can we guys make the -a thing default
when detect that we're running only uncore events which all should need
-a anyway?

Otherwise people who, like me, don't know that, would try to do
measurements and see the <not supported> and wonder...

Lemme add some more people to CC.

--
Regards/Gruss,
Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.