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Subject: Re: [PATCH v2]: perf/core: addressing 4x slowdown during per-process,
 profiling of STREAM benchmark on Intel Xeon Phi
From: Alexey Budankov <alexey.budankov@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Andi Kleen <ak@linux.intel.com>, Kan Liang <kan.liang@intel.com>,
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        Valery Cherepennikov <valery.cherepennikov@intel.com>,
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        Stephane Eranian <eranian@google.com>,
        Mark Rutland <mark.rutland@arm.com>, linux-kernel@vger.kernel.org
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Date: Thu, 15 Jun 2017 20:42:39 +0300
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On 29.05.2017 14:45, Alexey Budankov wrote:
> On 29.05.2017 14:23, Peter Zijlstra wrote:
>> On Mon, May 29, 2017 at 01:56:05PM +0300, Alexey Budankov wrote:
>>> On 29.05.2017 13:43, Peter Zijlstra wrote:
>>
>>>> Why can't the tree do both?
>>>>
>>>
>>> Well, indeed, the tree provides such capability too. However 
>>> switching to
>>> the full tree iteration in cases where we now go through _groups 
>>> lists will
>>> enlarge the patch, what is probably is not a big deal. Do you think 
>>> it is
>>> worth implementing the switch?
>>
>> Do it as a series of patches, where patch 1 introduces the tree, patches
>> 2 through n convert the list users into tree users, and patch n+1
>> removes the list.
> 
> Well ok, let's do that additionally but please expect delay in delivery 
> (I am OOO till Jun 14).

addressed in v3.

> 
>>
>> I think its good to not have duplicate data structures if we can avoid
>> it.
>>
> 
> yeah, makes sense.
> 
> 
>