perf jevents: Ignore sys when determining a model directory

Existing sys directories aren't placed under a model directory like
skylake.

Placing a sys directory there causes the `is_leaf_dir` test to fail and
consequently no events or metrics are generated for the model.

Ignore sys directories in this case and update the comments to
reflect why.

This change has no affect, but when testing with a sys directory for a
model people have reported running into the no event/metric issue.

Reported-by: Stephane Eranian <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jing Zhang <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sandipan Das <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Xu Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions