perf evlist: Fix evlist__new_default() for > 1 core PMU
authorJames Clark <james.clark@arm.com>
Wed, 24 Jan 2024 09:43:57 +0000 (09:43 +0000)
committerNamhyung Kim <namhyung@kernel.org>
Wed, 24 Jan 2024 22:13:48 +0000 (14:13 -0800)
commit63f209b6fa4d810ee159cb38c1c6c8e2d516920c
tree1892dd0671fa9fbaca759da4a9f078fbaf172eab
parent821aca20be503a6ce96ebda68c09fbcb1f7c51ba
perf evlist: Fix evlist__new_default() for > 1 core PMU

The 'Session topology' test currently fails with this message when
evlist__new_default() opens more than one event:

  32: Session topology                                                :
  --- start ---
  templ file: /tmp/perf-test-vv5YzZ
  Using CPUID 0x00000000410fd070
  Opening: unknown-hardware:HG
  ------------------------------------------------------------
  perf_event_attr:
    type                             0 (PERF_TYPE_HARDWARE)
    config                           0xb00000000
    disabled                         1
  ------------------------------------------------------------
  sys_perf_event_open: pid 0  cpu -1  group_fd -1  flags 0x8 = 4
  Opening: unknown-hardware:HG
  ------------------------------------------------------------
  perf_event_attr:
    type                             0 (PERF_TYPE_HARDWARE)
    config                           0xa00000000
    disabled                         1
  ------------------------------------------------------------
  sys_perf_event_open: pid 0  cpu -1  group_fd -1  flags 0x8 = 5
  non matching sample_type
  FAILED tests/topology.c:73 can't get session
  ---- end ----
  Session topology: FAILED!

This is because when re-opening the file and parsing the header, Perf
expects that any file that has more than one event has the sample ID
flag set. Perf record already sets the flag in a similar way when there
is more than one event, so add the same logic to evlist__new_default().

evlist__new_default() is only currently used in tests, so I don't
expect this change to have any other side effects. The other tests that
use it don't save and re-open the file so don't hit this issue.

The session topology test has been failing on Arm big.LITTLE platforms
since commit 251aa040244a ("perf parse-events: Wildcard most
"numeric" events") when evlist__new_default() started opening multiple
events for 'cycles'.

Fixes: 251aa040244a ("perf parse-events: Wildcard most "numeric" events")
Closes: https://lore.kernel.org/lkml/CAP-5=fWVQ-7ijjK3-w1q+k2WYVNHbAcejb-xY0ptbjRw476VKA@mail.gmail.com/
Tested-by: Ian Rogers <irogers@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20240124094358.489372-1-james.clark@arm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
tools/perf/util/evlist.c