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

Date: Tue, 6 Aug 2019 11:46:06 +0300

Subject: perf intel-pt: Add brief documentation for PEBS via Intel PT

Git-commit: 243384dd25c8ea721c5c82a229eaf33cbd1bfd52

Patch-mainline: v5.4-rc1

References: JIRA#SLE-9874

​

Document how to select PEBS via Intel PT and how to display synthesized

PEBS samples.

​

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>

Cc: Jiri Olsa <jolsa@kernel.org>

Cc: Kan Liang <kan.liang@linux.intel.com>

Cc: Namhyung Kim <namhyung@kernel.org>

Cc: Peter Zijlstra <peterz@infradead.org>

Link: http://lkml.kernel.org/r/20190806084606.4021-8-alexander.shishkin@linux.intel.com

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>

[ Update the example to use a group with intel_pt// as the group leader, as per Alex comment ]

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Tony Jones <tonyj@suse.de>

---

 tools/perf/Documentation/intel-pt.txt | 15 +++++++++++++++

 1 file changed, 15 insertions(+)

​

diff --git a/tools/perf/Documentation/intel-pt.txt b/tools/perf/Documentation/intel-pt.txt

index 50c5b60101bd..e0d9e7dd4f17 100644

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

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

@@ -919,3 +919,18 @@ amended to take the number of elements as a parameter.

 Note there is currently no advantage to using Intel PT instead of LBR, but

 that may change in the future if greater use is made of the data.

+

+

+PEBS via Intel PT

+=================

+

+Some hardware has the feature to redirect PEBS records to the Intel PT trace.

+Recording is selected by using the aux-output config term e.g.

+

+   perf record -c 10000 -e '{intel_pt/branch=0/,cycles/aux-output/ppp}' uname

+

+Note that currently, software only supports redirecting at most one PEBS event.

+

+To display PEBS events from the Intel PT trace, use the itrace 'o' option e.g.

+

+   perf script --itrace=oe

​

​