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    Subject[tip:perf/core] perf intel-pt: Accumulate cycle count from TSC/TMA/MTC packets
    Commit-ID:  3f05516758bef438cef7adc47599f8b8faad7c3a
    Gitweb: https://git.kernel.org/tip/3f05516758bef438cef7adc47599f8b8faad7c3a
    Author: Adrian Hunter <adrian.hunter@intel.com>
    AuthorDate: Mon, 20 May 2019 14:37:17 +0300
    Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
    CommitDate: Wed, 5 Jun 2019 09:47:56 -0300

    perf intel-pt: Accumulate cycle count from TSC/TMA/MTC packets

    When CYC packets are not available, it is still possible to count cycles
    using TSC/TMA/MTC timestamps.

    As the timestamp increments in TSC ticks, convert to CPU cycles using
    the current core-to-bus ratio.

    Do not accumulate cycles when control flow packet generation is not
    enabled, nor when time has been "lost", typically due to mwait, which is
    indicated by a TSC/TMA packet that is not part of PSB+.

    Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Jiri Olsa <jolsa@redhat.com>
    Link: http://lkml.kernel.org/r/20190520113728.14389-12-adrian.hunter@intel.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    ---
    .../perf/util/intel-pt-decoder/intel-pt-decoder.c | 51 ++++++++++++++++++++++
    1 file changed, 51 insertions(+)

    diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    index 99773445872d..9eb778f9c911 100644
    --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
    @@ -163,6 +163,9 @@ struct intel_pt_decoder {
    uint64_t last_masked_timestamp;
    uint64_t tot_cyc_cnt;
    uint64_t sample_tot_cyc_cnt;
    + uint64_t base_cyc_cnt;
    + uint64_t cyc_cnt_timestamp;
    + double tsc_to_cyc;
    bool continuous_period;
    bool overflow;
    bool set_fup_tx_flags;
    @@ -1423,6 +1426,42 @@ static int intel_pt_overflow(struct intel_pt_decoder *decoder)
    return -EOVERFLOW;
    }

    +static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
    +{
    + if (decoder->have_cyc)
    + return;
    +
    + decoder->cyc_cnt_timestamp = decoder->timestamp;
    + decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
    +}
    +
    +static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
    +{
    + decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
    +
    + if (decoder->pge)
    + intel_pt_mtc_cyc_cnt_pge(decoder);
    +}
    +
    +static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
    +{
    + uint64_t tot_cyc_cnt, tsc_delta;
    +
    + if (decoder->have_cyc)
    + return;
    +
    + decoder->sample_cyc = true;
    +
    + if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
    + return;
    +
    + tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
    + tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
    +
    + if (tot_cyc_cnt > decoder->tot_cyc_cnt)
    + decoder->tot_cyc_cnt = tot_cyc_cnt;
    +}
    +
    static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
    {
    uint32_t ctc = decoder->packet.payload;
    @@ -1432,6 +1471,11 @@ static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
    if (!decoder->tsc_ctc_ratio_d)
    return;

    + if (decoder->pge && !decoder->in_psb)
    + intel_pt_mtc_cyc_cnt_pge(decoder);
    + else
    + intel_pt_mtc_cyc_cnt_upd(decoder);
    +
    decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
    decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
    if (decoder->tsc_ctc_mult) {
    @@ -1487,6 +1531,8 @@ static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
    else
    decoder->timestamp = timestamp;

    + intel_pt_mtc_cyc_cnt_upd(decoder);
    +
    decoder->timestamp_insn_cnt = 0;
    decoder->last_mtc = mtc;

    @@ -1511,6 +1557,8 @@ static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)

    decoder->cbr = cbr;
    decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
    +
    + intel_pt_mtc_cyc_cnt_cbr(decoder);
    }

    static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
    @@ -1706,6 +1754,7 @@ static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
    decoder->state.to_ip = decoder->ip;
    }
    decoder->state.type |= INTEL_PT_TRACE_BEGIN;
    + intel_pt_mtc_cyc_cnt_pge(decoder);
    return 0;

    case INTEL_PT_TIP:
    @@ -1776,6 +1825,7 @@ next:

    case INTEL_PT_TIP_PGE: {
    decoder->pge = true;
    + intel_pt_mtc_cyc_cnt_pge(decoder);
    if (decoder->packet.count == 0) {
    intel_pt_log_at("Skipping zero TIP.PGE",
    decoder->pos);
    @@ -2138,6 +2188,7 @@ static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)

    case INTEL_PT_TIP_PGE:
    decoder->pge = true;
    + intel_pt_mtc_cyc_cnt_pge(decoder);
    if (intel_pt_have_ip(decoder))
    intel_pt_set_ip(decoder);
    if (!decoder->ip)
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