Re: BISECTED: perf test 'Miscellaneous Intel PT' failing on Intel hybrid machines

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Tue, Apr 09, 2024 at 12:32:06PM -0300, Arnaldo Carvalho de Melo wrote:
> root@x1:~# perf test "Miscellaneous Intel PT testing"
> 112: Miscellaneous Intel PT testing                                  : FAILED!
> root@x1:~#
> 
> then I revert:
> 
> commit 642e1ac96aaa12aeb41402e68eac7faf5917a67a (HEAD -> perf-tools-next)
> Author: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date:   Tue Apr 9 12:28:49 2024 -0300
> 
>     Revert "perf pmus: Check if we can encode the PMU number in perf_event_attr.type"
>     
>     This reverts commit 82fe2e45cdb00de4fa648050ae33bdadf9b3294a.
> ⬢[acme@toolbox perf-tools-next]$
> 
> It works now:
> 
> root@x1:~# perf -v
> perf version 6.8.g642e1ac96aaa
> root@x1:~# perf test "Miscellaneous Intel PT testing"
> 117: Miscellaneous Intel PT testing                                  : Ok
> root@x1:~#
> 
> Investigating, if you come up with ideas, lemme know.

Some more context:

When this patch was implemented/tested I had access only to an ARM64
hybrid machine, now my notebook is a Rocket Lake lenovo (13th gen), that
is hybrid and the test is failing with:

root@x1:~# perf test -v "Miscellaneous Intel PT testing"
112: Miscellaneous Intel PT testing                                  :
--- start ---
test child forked, pid 304355
--- Test system-wide sideband ---
Checking for CPU-wide recording on CPU 0
OK
Checking for CPU-wide recording on CPU 1
OK
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.934 MB /tmp/perf-test-intel-pt-sh.xACV6V7Hn4/test-perf.data ]
OK
--- Test per-thread recording ---
Workload PIDs are 304377 and 304378
perf PID is 304389
Waiting for "perf record has started" message
OK
pid 0 cpu -1 fd 5 : sys_perf_event_open: pid 0  cpu -1  group_fd -1  flags 0x8 = 5
pid 0 cpu -1 fd 6 : sys_perf_event_open: pid 0  cpu -1  group_fd -1  flags 0x8 = 6
pid 304377 cpu -1 fd 7 : sys_perf_event_open: pid 304377  cpu -1  group_fd -1  flags 0x8 = 7
pid 304380 cpu -1 fd 8 : sys_perf_event_open: pid 304380  cpu -1  group_fd -1  flags 0x8 = 8
pid 304378 cpu -1 fd 9 : sys_perf_event_open: pid 304378  cpu -1  group_fd -1  flags 0x8 = 9
pid 304381 cpu -1 fd 10 : sys_perf_event_open: pid 304381  cpu -1  group_fd -1  flags 0x8 = 10
pid 304377 cpu -1 fd 11 : sys_perf_event_open: pid 304377  cpu -1  group_fd -1  flags 0x8 = 11
pid 304380 cpu -1 fd 12 : sys_perf_event_open: pid 304380  cpu -1  group_fd -1  flags 0x8 = 12
pid 304378 cpu -1 fd 13 : sys_perf_event_open: pid 304378  cpu -1  group_fd -1  flags 0x8 = 13
pid 304381 cpu -1 fd 14 : sys_perf_event_open: pid 304381  cpu -1  group_fd -1  flags 0x8 = 14
fd 7 : idx 0: mmapping fd 7
fd 11 fd_to 7 : idx 0: set output fd 11 -> 7
fd 8 : idx 1: mmapping fd 8
fd 12 fd_to 8 : idx 1: set output fd 12 -> 8
fd 9 : idx 2: mmapping fd 9
fd 13 fd_to 9 : idx 2: set output fd 13 -> 9
fd 10 : idx 3: mmapping fd 10
fd 14 fd_to 10 : idx 3: set output fd 14 -> 10
Checking 10 fds
No mmap for fd 5