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authorAdrian Hunter <adrian.hunter@intel.com>2021-04-30 10:03:00 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-05-12 12:43:10 -0300
commite9d64739635f8db204c9fc81f20ed70751b4e0dd (patch)
tree02079fbabb89cae96a9d8c0a1e23f137d89814a4 /tools/perf/Documentation
parentperf intel-pt: Move synth_opts initialization earlier (diff)
downloadlinux-dev-e9d64739635f8db204c9fc81f20ed70751b4e0dd.tar.xz
linux-dev-e9d64739635f8db204c9fc81f20ed70751b4e0dd.zip
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: 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>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-intel-pt.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt
index 1dcec73c910c..33df7898c378 100644
--- a/tools/perf/Documentation/perf-intel-pt.txt
+++ b/tools/perf/Documentation/perf-intel-pt.txt
@@ -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
~~~~~~~~~~~