perf tools: Fix Intel PT 'instructions' sample period

The period on synthesized 'instructions' samples was being set to a
fixed value, whereas the correct value is the number of instructions
since the last sample, which is a value that the decoder can provide.
So do it that way.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1437150840-31811-14-git-send-email-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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

@@ -108,6 +108,7 @@ struct intel_pt_decoder {
 	uint64_t sign_bits;
 	uint64_t period;
 	enum intel_pt_period_type period_type;
+	uint64_t tot_insn_cnt;
 	uint64_t period_insn_cnt;
 	uint64_t period_mask;
 	uint64_t period_ticks;
@@ -559,6 +560,7 @@ static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
 	err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
 				 max_insn_cnt, decoder->data);
 
+	decoder->tot_insn_cnt += insn_cnt;
 	decoder->timestamp_insn_cnt += insn_cnt;
 	decoder->period_insn_cnt += insn_cnt;
 
@@ -1529,6 +1531,7 @@ const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
 	decoder->state.timestamp = decoder->timestamp;
 	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
 	decoder->state.cr3 = decoder->cr3;
+	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
 
 	if (err)
 		decoder->state.from_ip = decoder->ip;

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

@@ -58,6 +58,7 @@ struct intel_pt_state {
 	uint64_t from_ip;
 	uint64_t to_ip;
 	uint64_t cr3;
+	uint64_t tot_insn_cnt;
 	uint64_t timestamp;
 	uint64_t est_timestamp;
 	uint64_t trace_nr;

tools/perf/util/intel-pt.c

@@ -126,6 +126,7 @@ struct intel_pt_queue {
 	u64 timestamp;
 	u32 flags;
 	u16 insn_len;
+	u64 last_insn_cnt;
 };
 
 static void intel_pt_dump(struct intel_pt *pt __maybe_unused,
@@ -920,11 +921,13 @@ static int intel_pt_synth_instruction_sample(struct intel_pt_queue *ptq)
 	sample.addr = ptq->state->to_ip;
 	sample.id = ptq->pt->instructions_id;
 	sample.stream_id = ptq->pt->instructions_id;
-	sample.period = ptq->pt->instructions_sample_period;
+	sample.period = ptq->state->tot_insn_cnt - ptq->last_insn_cnt;
 	sample.cpu = ptq->cpu;
 	sample.flags = ptq->flags;
 	sample.insn_len = ptq->insn_len;
 
+	ptq->last_insn_cnt = ptq->state->tot_insn_cnt;
+
 	if (pt->synth_opts.callchain) {
 		thread_stack__sample(ptq->thread, ptq->chain,
 				     pt->synth_opts.callchain_sz, sample.ip);