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

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Message-ID: <20170215111340.myr3aecozzepxcx6@pd.tnic>
Date:   Wed, 15 Feb 2017 12:13:40 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Jiri Olsa <jolsa@...hat.com>
Cc:     Suravee Suthikulpanit <Suravee.Suthikulpanit@....com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>, Ingo Molnar <mingo@...nel.org>,
        linux-kernel@...r.kernel.org, iommu@...ts.linux-foundation.org,
        peterz@...radead.org, joro@...tes.org, mingo@...hat.com
Subject: Re: [PATCH v9 0/8] perf/amd/iommu: Enable multi-IOMMU support

On Wed, Feb 15, 2017 at 11:44:24AM +0100, Jiri Olsa wrote:
> does it say unsupported when you omit -a?

Yeah, it does dump the event name like it was counting but then it says
<not supported>. For example:

   <not supported>      amd_iommu_0/...

> [jolsa@...va perf]$ ./perf stat -e 'cpu/cpu-cycles/'
	 ^^^^^

Haha, I chuckle everytime I see this hostname :-)))

> > 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?
> 
> it's possible, can't think of anything being hurt by this now..

Right, so Peter meant something simple like: you parse all events, see
that they're all uncore and enable system_wide if so.

I get the feeling that we want to do that for uncore-only events
anyway...

-- 
Regards/Gruss,
    Boris.

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