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Date: Fri, 15 Nov 2013 11:05:06 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Stephane Eranian <eranian@google.com>, LKML <linux-kernel@vger.kernel.org>,
        Jiri Olsa <jolsa@redhat.com>, "mingo@elte.hu" <mingo@elte.hu>,
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        "ak@linux.intel.com" <ak@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Namhyung Kim <namhyung.kim@lge.com>
Subject: Re: [BUG] perf stat: explicit grouping yields unexpected results
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On Fri, Nov 15, 2013 at 07:34:57AM +0100, Ingo Molnar wrote:
> Btw., does the kernel side currently support discovery of such 
> impossible group scheduling constraints at group setup time? 

Up to a point.

> If not 
> then it probably should and it should reject them straight away.

We do I think, for the case where its obvious it can never fit.

That said, if you have a pinned cpu event, it all comes apart.