Messages in this thread | | | From | Ian Rogers <> | Date | Thu, 20 May 2021 08:21:12 -0700 | Subject | Re: [PATCH][Ping] perf test: Test 17 fails with make LIBPFM4=1 on s390 z/VM |
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On Thu, May 20, 2021 at 6:52 AM Thomas Richter <tmricht@linux.ibm.com> wrote: > > This test case fails on s390 virtual machine z/VM which has no PMU support > when the perf tool is built with LIBPFM4=1. > > Using make LIBPFM4=1 builds the perf tool with support for libpfm > event notation. The command line flag --pfm-events is valid: > # ./perf record --pfm-events cycles -- true > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.001 MB perf.data (2 samples) ] > # > > However the command 'perf test -Fv 17' fails on s390 z/VM virtual machine > with LIBPFM4=1: > # perf test -Fv 17 > 17: Setup struct perf_event_attr : > --- start --- > ..... > running './tests/attr/test-record-group2' > unsupp './tests/attr/test-record-group2' > running './tests/attr/test-record-pfm-period' > expected exclude_hv=0, got 1 > FAILED './tests/attr/test-record-pfm-period' - match failure > ---- end ---- > Setup struct perf_event_attr: FAILED! > > When --pfm-event system is not supported, the test returns unsupported > and continues. Here is an example using a virtual machine on x86 and > Fedora 34: > [root@f33 perf]# perf test -Fv 17 > 17: Setup struct perf_event_attr : > --- start --- > ..... > running './tests/attr/test-record-group2' > unsupp './tests/attr/test-record-group2' > running './tests/attr/test-record-pfm-period' > unsupp './tests/attr/test-record-pfm-period' > .... > > The issue is file ./tests/attr/test-record-pfm-period > which requires perf event attribute member exclude_hv to be zero. > This is not the case on s390 where the value of exclude_hv is one when > executing on a z/VM virtual machine without PMU hardware support. > > Fix this by allowing value exlucde_hv to be zero or one. > > Output before: > # /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \ > test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match > matching [event:base-record] > match: [event:base-record] matches [] > FAILED './tests/attr//test-record-pfm-period' - match failure > # > > Output after: > # /usr/bin/python ./tests/attr.py -d ./tests/attr/ -t \ > test-record-pfm-period -p ./perf -vvv 2>&1| fgrep match > matching [event:base-record] > match: [event:base-record] matches ['event-1-0-6', 'event-1-0-5'] > matched > matching [event-1-0-6] > match: [event-1-0-6] matches ['event:base-record'] > matching [event-1-0-5] > match: [event-1-0-5] matches ['event:base-record'] > matched > # > > Background: > Using libpfm library ends up in this function call sequence > > pfm_get_perf_event_encoding() > +-- pfm_get_os_event_encoding() > +-- pfmlib_perf_event_encode() > > is called when no hardware specific PMU unit can be detected > as in the s390 z/VM virtual machine case. This uses the > "perf_events generic PMU" data structure which sets exclude_hv per default. > Using this PMU that test case always fails. > > That is the reason why exclude_hv attribute setting varies. > > Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> > Cc: Ian Rogers <irogers@google.com> > --- > tools/perf/tests/attr/test-record-pfm-period | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/tools/perf/tests/attr/test-record-pfm-period b/tools/perf/tests/attr/test-record-pfm-period > index 368f5b814094..b962d6d11ee2 100644 > --- a/tools/perf/tests/attr/test-record-pfm-period > +++ b/tools/perf/tests/attr/test-record-pfm-period > @@ -7,3 +7,4 @@ ret = 1 > sample_period=77777 > sample_type=7 > freq=0 > +exclude_hv=0|1
Presumably you see the same failure for other attribute checks, such as test-record-period? Would it make more sense to change base-record so that exclude_hv=0|1 ?
Thanks, Ian
> -- > 2.30.2 >
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