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Thomas Richteracmel
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perf test: Test 17 fails with make LIBPFM4=1 on s390 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. 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. Suggested-by: Ian Rogers <[email protected]> Signed-off-by: Thomas Richter <[email protected]> Reviewed-by: Ian Rogers <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Sumanth Korikkar <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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tools/perf/tests/attr/base-record

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exclusive=0
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exclude_user=0
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exclude_kernel=0|1
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exclude_hv=0
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exclude_hv=0|1
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exclude_idle=0
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