diff options
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/Documentation/perf-intel-pt.txt | 15 | ||||
| -rw-r--r-- | tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 18 |
2 files changed, 33 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt index f9fe4a4040ba..d5a266d7f15b 100644 --- a/tools/perf/Documentation/perf-intel-pt.txt +++ b/tools/perf/Documentation/perf-intel-pt.txt @@ -999,6 +999,21 @@ What *will* be decoded with the (single) q option: Note the q option does not specify what events will be synthesized e.g. the p option must be used also to show power events. +Repeating the q option (double-q i.e. qq) results in even faster decoding and even +less detail. The decoder decodes only extended PSB (PSB+) packets, getting the +instruction pointer if there is a FUP packet within PSB+ (i.e. between PSB and +PSBEND). Note PSB packets occur regularly in the trace based on the psb_period +config term (refer config terms section). There will be a FUP packet if the +PSB+ occurs while control flow is being traced. + +What will *not* be decoded with the qq option: + + - everything except instruction pointer associated with PSB packets + +What *will* be decoded with the qq option: + + - instruction pointer associated with PSB packets + dump option ~~~~~~~~~~~ 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 ccb204b1a050..697513f35154 100644 --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -113,6 +113,7 @@ struct intel_pt_decoder { bool in_psb; bool hop; bool hop_psb_fup; + bool leap; enum intel_pt_param_flags flags; uint64_t pos; uint64_t last_ip; @@ -240,6 +241,7 @@ struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) decoder->return_compression = params->return_compression; decoder->branch_enable = params->branch_enable; decoder->hop = params->quick >= 1; + decoder->leap = params->quick >= 2; decoder->flags = params->flags; @@ -1903,9 +1905,18 @@ static int intel_pt_resample(struct intel_pt_decoder *decoder) #define HOP_RETURN 2 #define HOP_AGAIN 3 +static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder); + /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err) { + /* Leap from PSB to PSB, getting ip from FUP within PSB+ */ + if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) { + *err = intel_pt_scan_for_psb(decoder); + if (*err) + return HOP_RETURN; + } + switch (decoder->packet.type) { case INTEL_PT_TNT: return HOP_IGNORE; @@ -2681,6 +2692,7 @@ static int intel_pt_sync(struct intel_pt_decoder *decoder) decoder->ip = 0; intel_pt_clear_stack(&decoder->stack); +leap: err = intel_pt_scan_for_psb(decoder); if (err) return err; @@ -2702,6 +2714,12 @@ static int intel_pt_sync(struct intel_pt_decoder *decoder) decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + } else if (decoder->leap) { + /* + * In leap mode, only PSB+ is decoded, so keeping leaping to the + * next PSB until there is an ip. + */ + goto leap; } else { return intel_pt_sync_ip(decoder); } |