Re: perf test hybrid failing on 14700K

From: Ian Rogers
Date: Sat Jan 20 2024 - 01:09:34 EST


On Sat, Dec 23, 2023 at 5:55 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Hi Kan,
>
> I noticed the following problem, are you able to reproduce it?
>
> Happy solstice!
>
> - Arnaldo

Hi Arnaldo,

I'm seeing a test failure on Alderlake in perf-tools-next and wondered
if it was on your radar:
```
32: Session topology :
--- start ---
test child forked, pid 539222
templ file: /tmp/perf-test-HMet21
Using CPUID GenuineIntel-6-97-2
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0x800000000
disabled 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 4
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0x400000000
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
test child finished with -1
---- end ----
Session topology: FAILED!
```

The code is hitting this line in evlist__valid_sample_type as
core.nr_entries is 2 on hybrid not 1:
https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/util/evlist.c?h=perf-tools-next#n1215
this causes perf_session__open to fail:
https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/util/session.c?h=perf-tools-next#n129

Thanks,
Ian