4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Adrian Hunter <adrian.hun...@intel.com>

commit 3f04d98e972b59706bd43d6cc75efac91f8fba50 upstream.

The decoder uses its current timestamp in samples. Usually that is a
timestamp that has already passed, but in some cases it is a timestamp
for a branch that the decoder is walking towards, and consequently
hasn't reached. Improve that situation by using the pkt_state to
determine when to use the current or previous timestamp.

Signed-off-by: Adrian Hunter <adrian.hun...@intel.com>
Cc: Andi Kleen <a...@linux.intel.com>
Link: 
http://lkml.kernel.org/r/1495786658-18063-3-git-send-email-adrian.hun...@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 tools/perf/util/intel-pt-decoder/intel-pt-decoder.c |   34 ++++++++++++++++++--
 1 file changed, 31 insertions(+), 3 deletions(-)

--- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
+++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
@@ -64,6 +64,25 @@ enum intel_pt_pkt_state {
        INTEL_PT_STATE_FUP_NO_TIP,
 };
 
+static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
+{
+       switch (pkt_state) {
+       case INTEL_PT_STATE_NO_PSB:
+       case INTEL_PT_STATE_NO_IP:
+       case INTEL_PT_STATE_ERR_RESYNC:
+       case INTEL_PT_STATE_IN_SYNC:
+       case INTEL_PT_STATE_TNT:
+               return true;
+       case INTEL_PT_STATE_TIP:
+       case INTEL_PT_STATE_TIP_PGD:
+       case INTEL_PT_STATE_FUP:
+       case INTEL_PT_STATE_FUP_NO_TIP:
+               return false;
+       default:
+               return true;
+       };
+}
+
 #ifdef INTEL_PT_STRICT
 #define INTEL_PT_STATE_ERR1    INTEL_PT_STATE_NO_PSB
 #define INTEL_PT_STATE_ERR2    INTEL_PT_STATE_NO_PSB
@@ -98,6 +117,7 @@ struct intel_pt_decoder {
        uint64_t timestamp;
        uint64_t tsc_timestamp;
        uint64_t ref_timestamp;
+       uint64_t sample_timestamp;
        uint64_t ret_addr;
        uint64_t ctc_timestamp;
        uint64_t ctc_delta;
@@ -140,6 +160,7 @@ struct intel_pt_decoder {
        unsigned int fup_tx_flags;
        unsigned int tx_flags;
        uint64_t timestamp_insn_cnt;
+       uint64_t sample_insn_cnt;
        uint64_t stuck_ip;
        int no_progress;
        int stuck_ip_prd;
@@ -896,6 +917,7 @@ static int intel_pt_walk_insn(struct int
 
        decoder->tot_insn_cnt += insn_cnt;
        decoder->timestamp_insn_cnt += insn_cnt;
+       decoder->sample_insn_cnt += insn_cnt;
        decoder->period_insn_cnt += insn_cnt;
 
        if (err) {
@@ -2035,7 +2057,7 @@ static int intel_pt_sync(struct intel_pt
 
 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
 {
-       uint64_t est = decoder->timestamp_insn_cnt << 1;
+       uint64_t est = decoder->sample_insn_cnt << 1;
 
        if (!decoder->cbr || !decoder->max_non_turbo_ratio)
                goto out;
@@ -2043,7 +2065,7 @@ static uint64_t intel_pt_est_timestamp(s
        est *= decoder->max_non_turbo_ratio;
        est /= decoder->cbr;
 out:
-       return decoder->timestamp + est;
+       return decoder->sample_timestamp + est;
 }
 
 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
@@ -2099,11 +2121,17 @@ const struct intel_pt_state *intel_pt_de
        if (err) {
                decoder->state.err = intel_pt_ext_err(err);
                decoder->state.from_ip = decoder->ip;
+               decoder->sample_timestamp = decoder->timestamp;
+               decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
        } else {
                decoder->state.err = 0;
+               if (intel_pt_sample_time(decoder->pkt_state)) {
+                       decoder->sample_timestamp = decoder->timestamp;
+                       decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
+               }
        }
 
-       decoder->state.timestamp = decoder->timestamp;
+       decoder->state.timestamp = decoder->sample_timestamp;
        decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
        decoder->state.cr3 = decoder->cr3;
        decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;


Reply via email to