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

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>
This commit is contained in:
Adrian Hunter 2019-08-06 11:46:06 +03:00 committed by Arnaldo Carvalho de Melo
parent 1b9921546a
commit 243384dd25

View File

@ -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