Messages in this thread Patch in this message | | | From | Thomas Richter <> | Subject | [PATCH V2] perf test: Test 17 fails with make LIBPFM4=1 on s390 z/VM | Date | Fri, 21 May 2021 11:00:04 +0200 |
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Version 2: As suggested by Ian Rogers make perf_event_attribute member exclude_hv more robust and accept value 0 or 1 to handle more test cases which might fail on s390 virtual machine z/VM.
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
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 to 1 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> Suggested-by: Ian Rogers <irogers@google.com> --- tools/perf/tests/attr/base-record | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/tests/attr/base-record b/tools/perf/tests/attr/base-record index 4a7b8deef3fd..8c10955eff93 100644 --- a/tools/perf/tests/attr/base-record +++ b/tools/perf/tests/attr/base-record @@ -16,7 +16,7 @@ pinned=0 exclusive=0 exclude_user=0 exclude_kernel=0|1 -exclude_hv=0 +exclude_hv=0|1 exclude_idle=0 mmap=1 comm=1 -- 2.31.1
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