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    Subject[PATCH 4.4 053/241] perf intel-pt: Fix sample timestamp wrt non-taken branches
    Date
    From: Adrian Hunter <adrian.hunter@intel.com>

    commit 1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 upstream.

    The sample timestamp is updated to ensure that the timestamp represents
    the time of the sample and not a branch that the decoder is still
    walking towards. The sample timestamp is updated when the decoder
    returns, but the decoder does not return for non-taken branches. Update
    the sample timestamp then also.

    Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample
    timestamp") was also a stable fix and appears, for example, in v4.4
    stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample
    timestamp").

    Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Cc: stable@vger.kernel.org # v4.4+
    Fixes: 3f04d98e972b ("perf intel-pt: Improve sample timestamp")
    Link: http://lkml.kernel.org/r/20190510124143.27054-4-adrian.hunter@intel.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 5 ++++-
    1 file changed, 4 insertions(+), 1 deletion(-)

    --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    @@ -1205,8 +1205,11 @@ static int intel_pt_walk_tnt(struct inte
    return 0;
    }
    decoder->ip += intel_pt_insn.length;
    - if (!decoder->tnt.count)
    + if (!decoder->tnt.count) {
    + decoder->sample_timestamp = decoder->timestamp;
    + decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
    return -EAGAIN;
    + }
    decoder->tnt.payload <<= 1;
    continue;
    }

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