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Date: Wed, 26 Feb 2014 08:04:00 +0100
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Subject: Re: [PATCH v3 00/14] perf, x86: Haswell LBR call stack support
From: Stephane Eranian <eranian@google.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "Yan, Zheng" <zheng.z.yan@intel.com>, LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Ingo Molnar <mingo@kernel.org>,
        Arnaldo Carvalho de Melo <acme@infradead.org>,
        Andi Kleen <andi@firstfloor.org>
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On Wed, Feb 26, 2014 at 3:39 AM, Andy Lutomirski <luto@amacapital.net> wrote:
> On 02/17/2014 10:07 PM, Yan, Zheng wrote:
>>
>> This patch series adds LBR call stack support. User can enabled/disable
>> this through an sysfs attribute file in the CPU PMU directory:
>>  echo 1 > /sys/bus/event_source/devices/cpu/lbr_callstack
>
> This seems like an unpleasant way to control this.  It would be handy to
> be able to control this as an option to perf record.
>
That would mean you'd be root for perf.
Or are you suggesting a perf event option? But then, you'd expose arch-specific
feature at the API level.

> --Andy