Messages in this thread | | | Date | Tue, 13 Aug 2019 10:51:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v6 7/7] perf intel-pt: Add brief documentation for PEBS via Intel PT |
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Em Tue, Aug 06, 2019 at 11:46:06AM +0300, Alexander Shishkin escreveu: > From: Adrian Hunter <adrian.hunter@intel.com> > > Document how to select PEBS via Intel PT and how to display synthesized > PEBS samples. > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> > --- > 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..8dc513b6607b 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 cycles/aux-output/ppp -e intel_pt/branch=0/ uname > + > +Note that currently, software only supports redirecting at most one PEBS event.
So, with these patches, but not the kernel ones I end up getting:
[root@quaco ~]# perf record -c 10000 -e cycles/aux-output/ppp -e intel_pt/branch=0/ uname Error: The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (cycles/aux-output/ppp). /bin/dmesg | grep -i perf may provide additional information.
[root@quaco ~]#
I'll check if I can make it spew a more helpful message, then build a kernel with the kernel patches and try with it as well.
PeterZ has the kernel ones landed on tip? I guess not, as perf/core I have should be in sync...
- Arnaldo
> +To display PEBS events from the Intel PT trace, use the itrace 'o' option e.g. > + > + perf script --itrace=oe > -- > 2.20.1
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