perf evsel: Improve AMD IBS (Instruction-Based Sampling) error handling messages

Improve the error message returned on failed perf_event_open() on AMD
systems when using IBS (Instruction-Based Sampling).

Output of executing 'perf record -e ibs_op// true' as a non root user
BEFORE this patch (perf will add the 'u' modifier at the end to exclude
kernel/hypervisor sampling):

  The sys_perf_event_open() syscall returned with 22 (Invalid argument)for event (ibs_op//u).
  /bin/dmesg | grep -i perf may provide additional information.

Output after:

  AMD IBS can't exclude kernel events.  Try running at a higher privilege level.

Output of executing 'sudo perf record -e ibs_op// true' BEFORE this patch:

  Error:
  The sys_perf_event_open() syscall returned with 22 (Invalid argument) for event (ibs_op//).
  /bin/dmesg | grep -i perf may provide additional information.

Output after:

  Error:
  Invalid event (ibs_op//) in per-thread mode, enable system wide with '-a'.

Folowing the suggestion:

  $ sudo perf record -a -e ibs_op// true
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 1.664 MB perf.data (194 samples) ]
  $

Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: João Martins <joao.m.martins@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20220322221517.2510440-12-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

0 files changed, 0 insertions, 0 deletions