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Commit 3f055167 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
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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: default avatarAdrian 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f3c98c4b

tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

+51 −0
Original line number Diff line number Diff line
@@ -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 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) 


		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)