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Date: Thu, 19 Dec 2013 15:49:42 +0100
From: Frederic Weisbecker <fweisbec@gmail.com>
To: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>, Peter Zijlstra <peterz@infradead.org>,
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        Paul Mackerras <paulus@samba.org>,
        Stephane Eranian <eranian@google.com>, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH v0 04/71] itrace: Infrastructure for instruction flow
 tracing units
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On Thu, Dec 19, 2013 at 04:30:53PM +0200, Alexander Shishkin wrote:
> Or the interface and implementation of BTS support in the kernel
> discourage its use and that is why it is so rarely used.

I never heard complains about it. It's a simple dump of from/to address couples.
I just think nobody take the time to develop userspace tooling to exploit it.
But it's famous slowness might have had a bad influence on this. And may be
also the fact that it's very architecture specific. AMD doesn't support BTS if I recall
correctly. Or may be it has its own different implementation?