Commit e9d64739 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Support Z itrace option for timeless decoding 



Correlating virtual machine TSC packets is not supported at present, so
instead support the Z itrace option.

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/20210430070309.17624-4-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 856ecd6a

tools/perf/Documentation/perf-intel-pt.txt

+5 −0
Original line number Diff line number Diff line
@@ -869,6 +869,7 @@ The letters are: 
	L	synthesize last branch entries on existing event records

	s	skip initial number of events

	q	quicker (less detailed) decoding

	Z	prefer to ignore timestamps (so-called "timeless" decoding)



"Instructions" events look like they were recorded by "perf record -e

instructions".
@@ -1062,6 +1063,10 @@ What *will* be decoded with the qq option: 


	- instruction pointer associated with PSB packets



The Z option is equivalent to having recorded a trace without TSC

(i.e. config term tsc=0). It can be useful to avoid timestamp issues when

decoding a trace of a virtual machine.





dump option

~~~~~~~~~~~

tools/perf/util/intel-pt.c

+1 −1
Original line number Diff line number Diff line
@@ -899,7 +899,7 @@ static bool intel_pt_timeless_decoding(struct intel_pt *pt) 
	bool timeless_decoding = true;

	u64 config;



	if (!pt->tsc_bit || !pt->cap_user_time_zero)

	if (!pt->tsc_bit || !pt->cap_user_time_zero || pt->synth_opts.timeless_decoding)

		return true;



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