From: Markus Metzger <markus.t.metzger@intel.com>
Date: Tue, 21 Jul 2009 13:56:48 +0000 (+0200)
Subject: x86, perf_counter, bts: Add BTS support to perfcounters
X-Git-Tag: v2.6.32-rc1~720^2~50
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=30dd568c912602b7dbd609a45d053e01b13422bb;p=pandora-kernel.git

x86, perf_counter, bts: Add BTS support to perfcounters

Implement a performance counter with:

    attr.type           = PERF_TYPE_HARDWARE
    attr.config         = PERF_COUNT_HW_BRANCH_INSTRUCTIONS
    attr.sample_period  = 1

Using branch trace store (BTS) on x86 hardware, if available.

The from and to address for each branch can be sampled using:

    PERF_SAMPLE_IP      for the from address
    PERF_SAMPLE_ADDR    for the to address

[ v2: address review feedback, fix bugs ]

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

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