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

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

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi 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: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2021-04-30 10:03:00 +03:00 committed by Arnaldo Carvalho de Melo
parent 856ecd6ab4
commit e9d6473963
2 changed files with 6 additions and 1 deletions
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5
tools/perf/Documentation/perf-intel-pt.txt
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@ -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
~~~~~~~~~~~

2
tools/perf/util/intel-pt.c
View File

@ -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) {