Commit 6af4b600 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Fix IPC with CYC threshold 



The code assumed every CYC-eligible packet has a CYC packet, which is not
the case when CYC thresholds are used. Fix by checking if a CYC packet is
actually present in that case.

Fixes: 5b1dc0fd ("perf intel-pt: Add support for samples to contain IPC ratio")
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20210205175350.23817-4-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 20aa3970

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

+27 −0
Original line number Diff line number Diff line
@@ -24,6 +24,13 @@ 
#include "intel-pt-decoder.h"

#include "intel-pt-log.h"



#define BITULL(x) (1ULL << (x))



/* IA32_RTIT_CTL MSR bits */

#define INTEL_PT_CYC_ENABLE		BITULL(1)

#define INTEL_PT_CYC_THRESHOLD		(BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))

#define INTEL_PT_CYC_THRESHOLD_SHIFT	19



#define INTEL_PT_BLK_SIZE 1024



#define BIT63 (((uint64_t)1 << 63))
@@ -167,6 +174,8 @@ struct intel_pt_decoder { 
	uint64_t sample_tot_cyc_cnt;

	uint64_t base_cyc_cnt;

	uint64_t cyc_cnt_timestamp;

	uint64_t ctl;

	uint64_t cyc_threshold;

	double tsc_to_cyc;

	bool continuous_period;

	bool overflow;
@@ -204,6 +213,14 @@ static uint64_t intel_pt_lower_power_of_2(uint64_t x) 
	return x << i;

}



static uint64_t intel_pt_cyc_threshold(uint64_t ctl)

{

	if (!(ctl & INTEL_PT_CYC_ENABLE))

		return 0;



	return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;

}



static void intel_pt_setup_period(struct intel_pt_decoder *decoder)

{

	if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
@@ -245,12 +262,15 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) 


	decoder->flags              = params->flags;



	decoder->ctl                = params->ctl;

	decoder->period             = params->period;

	decoder->period_type        = params->period_type;



	decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;

	decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;



	decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);



	intel_pt_setup_period(decoder);



	decoder->mtc_shift = params->mtc_period;
@@ -2017,6 +2037,7 @@ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, in 


static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)

{

	int last_packet_type = INTEL_PT_PAD;

	bool no_tip = false;

	int err;
@@ -2025,6 +2046,12 @@ static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) 
		if (err)

			return err;

next:

		if (decoder->cyc_threshold) {

			if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)

				decoder->sample_cyc = false;

			last_packet_type = decoder->packet.type;

		}



		if (decoder->hop) {

			switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {

			case HOP_IGNORE:

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

+1 −0
Original line number Diff line number Diff line
@@ -244,6 +244,7 @@ struct intel_pt_params { 
	void *data;

	bool return_compression;

	bool branch_enable;

	uint64_t ctl;

	uint64_t period;

	enum intel_pt_period_type period_type;

	unsigned max_non_turbo_ratio;

tools/perf/util/intel-pt.c

+13 −0
Original line number Diff line number Diff line
@@ -893,6 +893,18 @@ static bool intel_pt_sampling_mode(struct intel_pt *pt) 
	return false;

}



static u64 intel_pt_ctl(struct intel_pt *pt)

{

	struct evsel *evsel;

	u64 config;



	evlist__for_each_entry(pt->session->evlist, evsel) {

		if (intel_pt_get_config(pt, &evsel->core.attr, &config))

			return config;

	}

	return 0;

}



static u64 intel_pt_ns_to_ticks(const struct intel_pt *pt, u64 ns)

{

	u64 quot, rem;
@@ -1026,6 +1038,7 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt, 
	params.data = ptq;

	params.return_compression = intel_pt_return_compression(pt);

	params.branch_enable = intel_pt_branch_enable(pt);

	params.ctl = intel_pt_ctl(pt);

	params.max_non_turbo_ratio = pt->max_non_turbo_ratio;

	params.mtc_period = intel_pt_mtc_period(pt);

	params.tsc_ctc_ratio_n = pt->tsc_ctc_ratio_n;