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Date: Mon, 29 May 2017 13:23:11 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
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Subject: Re: [PATCH v2]: perf/core: addressing 4x slowdown during
 per-process, profiling of STREAM benchmark on Intel Xeon Phi
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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.

I think its good to not have duplicate data structures if we can avoid
it.