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Date: Sat, 27 Feb 2016 15:48:09 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>, Ingo Molnar <mingo@kernel.org>,
        Andi Kleen <andi@firstfloor.org>,
        Stephane Eranian <eranian@google.com>, Wang Nan <wangnan0@huawei.com>,
        zheng.z.yan@intel.com, Kan Liang <kan.liang@intel.com>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] Core2 cpu triggers hard lockup with perf test
Message-ID: <20160227144809.GC6356@twins.programming.kicks-ass.net>
References: <20160227123636.GB30858@krava.redhat.com>
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On Sat, Feb 27, 2016 at 01:37:01PM +0100, Jiri Olsa wrote:
> we are getting hard lockups on Core2 cpus (model 23)

> I can't find what's special about Core2 CPU PEBS setup,
> it seems that oher CPUs are ok (tried on ivb/snb/hsw).
> 
> reverting the 156174999dd1 fixed the issue for me
> 
> ideas? thanks,

The obvious difference between Core2 and later chips is that Core2 only
has PEBS on a single counter (cnt0).

I'll try and have a closer look on Monday, I should still have a Core2
class machine around the house somewhere.